Brakes Fading
Jim Corey
I began having brake fading
problems -- loss of pedal, primarily after long continuous braking.
Thought it might be boiling fluid caused by heat transfer from the calipers,
(A known problem)
so had calipers replaced with new ones w/ phenolic pistons. No problems
for about a year, but the problem reappeared last week. I was in heavy stop
and go traffic for several miles. The pedal drifted to the floor; pumping
didn't help much, if at all. When the traffic picked up, the problem
disappeared. Any thoughts? I'm not running synthetic fluid. That's my
next fix. I have posted a similar inquiry on the Ford Truck newsgroup.
Zeke Hardscrabble
"Jim Corey" <jcor...@excite.com> wrote in message
news:WvzN8.11941$3w2....@typhoon.sonic.net...
Your pedal went to the floor and you were still driving it?? Get thee to a
brake shop and pay whatever they ask ....
Zeke H.
Lon VanOstran
Have your brake fluid changed. Yours is contaminated with water. After
this, ALWAYS change your brake fluid at least once every 3 years. Brake
fluid absorbe moisture out of the air, which lowers the boiling point.
Lon
Kenneth Shelton
fluid, DON'T. Use fresh DOT 4 brake fluid. Get it completely flushed every
two years.
http://www.tirekingdom.com/purch/brkfluid.html
The problems with DOT 5 brake fluid:
1) It's not compatible with DOT 3 or 4 or 5.1 glycol brake fluid. DOT 5
needs a new system with all clean passages.
2) DOT 5 is not suitable for ABS systems.
3) DOT 5 is about twice as compressible at the glycol fluids. You'll have
a spongy pedal feel.
Ken
Jim Corey
I said synthetic. The symptoms do indicate moisture in the fluid.
>>SNIP<<
Clark, D.
the fluid aquires about 10% water per year.
"Jim Corey" <jcor...@excite.com> wrote in message
news:WvzN8.11941$3w2....@typhoon.sonic.net...
Will Sill
>Jim try a new mastercilinder and flush and replace "ALL" the brake fluid, as
>the fluid aquires about 10% water per year.
Aha! Anoither brilliant bit of 'wisdom' from usenet. BS is still BS
when it appears in print. Brake fluid in a sealed container or
system does NOT absorb moisture.
DISCLAIMER:
My advice is useless. I have no university degrees and
have never towed a 34' TT with an Intrepid. Though I have
done some near-Darwin-award dumb things in the past, and
often still make errors, I currently own NO Banks headers,
fuel magnets, deer whistles, "Smart" solenoids or louvered
tailgates. I've never deliberately allowed a holding tank to
freeze solid, and have no financial interest in whether you
join RVCG, wear clothes, overinflate your tires or hate
Firestone. If you take my advice, I guarantee absolutely NOTHING.
Got that?
Will Sill KD3XR
Chris Bryant
>"Clark, D." <cqk...@msn.com> recently wrote these words:
>
>>Jim try a new mastercilinder and flush and replace "ALL" the brake fluid, as
>>the fluid aquires about 10% water per year.
>
>Aha! Anoither brilliant bit of 'wisdom' from usenet. BS is still BS
>when it appears in print. Brake fluid in a sealed container or
>system does NOT absorb moisture.
Except that the master cylinder is not sealed, and brake fluid
in a braking system can and does absorb moisture. There are test
strips you can buy to test the moisture in brake fluid, as well as
refractometers.
If I lived in Arizona, I wouldn'y worry as much, but in more
humid climes, 2-4 years is the recommended interval.
Just a tiny bit of research would give these facts.
--
Chris Bryant
Bryant RV Services- http://www.bryantrv.com
Will Sill
"Clark, D." <cqk...@msn.com> :
>>>Jim try a new mastercilinder and flush and replace "ALL" the brake fluid, as
>>>the fluid aquires about 10% water per year.
Will:
>>Aha! Another brilliant bit of 'wisdom' from usenet. BS is still BS
>>when it appears in print. Brake fluid in a sealed container or
>>system does NOT absorb moisture.
Chris:
> Except that the master cylinder is not sealed, and brake fluid
>in a braking system can and does absorb moisture. There are test
>strips you can buy to test the moisture in brake fluid, as well as
>refractometers.
> If I lived in Arizona, I wouldn'y worry as much, but in more
>humid climes, 2-4 years is the recommended interval.
>
> Just a tiny bit of research would give these facts.
All the research I needed was to pop off the SEALED cover on my master
cylinders, under which is a diaphragm to keeps the system totally
airtight until/unless I remove the cover.
What tiny bit of research do your suggest that would be better?
Will KD3XR ---- the Curmudgeon of Sill Hill
Before flaming, pause. I post to help rv'ers
and annoy morons. Whichever shoe fits, wear it.
Chris Bryant
>All the research I needed was to pop off the SEALED cover on my master
>cylinders, under which is a diaphragm to keeps the system totally
>airtight until/unless I remove the cover.
>
>What tiny bit of research do your suggest that would be better?
http://www.google.com/search?hl=en&ie=UTF8&oe=UTF8&q=brake+fluid+moisture&btnG=Google+Search
Let me see- about 11,500 web pages which disagree with you.
Plus, you could look at the fluid- is it clear?- Mine isn't
(in my SEALED reservoir)- when it is no longer clear, it means there
is some contamination- hard to get in a SEALED reservoir.
Or, you could look at some recommended service intervals, and
note that flushing the brake fluid is recommended because of moisture
contamination.
Or- you could buy one of the test strips which indicates
moisture in the brake fluid and test your own.
Or, you could ignore it for a few years and pay the
consequences.
You are dead wrong, and gave dangerous advice.
Will Sill
useful contributors, takes off on a serious rant based on my objection
to a daft statement that:
" . . .the fluid aquires about 10% water per year."
Since I know that is NOT true, I wrote::
>> . . . . . Brake fluid in a sealed container or system does NOT absorb moisture.
Then Chris jumped in with:
> Except that the master cylinder is not sealed, and brake fluid
>in a braking system can and does absorb moisture. There are test
>strips you can buy to test the moisture in brake fluid, as well as
Then I offered:
>>All the research I needed was to pop off the SEALED cover on my master
>>cylinders, under which is a diaphragm to keeps the system totally
>>airtight until/unless I remove the cover.
>>
>>What tiny bit of research do your suggest that would be better?
Whereupon he responds with this stuff:
>http://www.google.com/search?hl=en&ie=UTF8&oe=UTF8&q=brake+fluid+moisture&btnG=Google+Search
>
> Let me see- about 11,500 web pages which disagree with you.
>
> Plus, you could look at the fluid- is it clear?- Mine isn't
>(in my SEALED reservoir)- when it is no longer clear, it means there
>is some contamination- hard to get in a SEALED reservoir.
>
> Or, you could look at some recommended service intervals, and
>note that flushing the brake fluid is recommended because of moisture
>contamination.
>
> Or- you could buy one of the test strips which indicates
>moisture in the brake fluid and test your own.
>
> Or, you could ignore it for a few years and pay the
>consequences.
>
> You are dead wrong, and gave dangerous advice.
No, Chris, I am absolutely NOT "dead wrong" nor did I give dangerous
advice. I challenged the misleading flat statement that " . . .the
fluid aquires about 10% water per year.", and later pointed out that a
sealed system doesn't permit moisture to be absorbed from the air.
The link you provided does NOT contradict anything I wrote. My owners
manual (GMC) makes NO reference to changing brake fluid, and my
11-year-old GMC pickup has almost certainly never had the fluid
changed. (No need to unseal the system unless it starts leaking
somewhere.)
Don't get me wrong - I DO agree that brake fluid absorbs moisture from
the air - but not 10% per year, and definitely not inside a sealed
system. Water in the fluid not only promotes rust but can lead to
brake failure. People who have trouble with moisture inside their
brake systems have it because the system was not kept sealed or was
filled with contaminated fluid.
Instead of throwing 11,500 pages at me, pony up some facts, Chris.
And BTW brake FADING is more often than not caused by overheating of
the lining material, and is not necessarily associated with water in
the fluid.
bill horne
While I won't argue about whether someone should periodically change
their brake fluid (some should), or whether DOT 3 is hydroscopic (it
is), I will say this:
The only car I've ever owned that recommended changing the fluid was an
88 Mazda.
Neither my 96 Chevy PU nor my 83 Chevy PU manuals require, or recommend,
periodically changing the brake fluid.
I've never changed the fluid in my 83, and I've had no hydraulic system
problems in the 19 years I've owned it.
The seals on the master cylinder lid of all vehicles I've owned since
1966 (can't remember the ones before that) have had full cover seals
that are designed to flex with the varying level of the fluid, to
prevent the sucking in of air and its contained moisture.
Unless the owner's manual for a specific vehicle says to do it, I see no
reason to 'periodically' change the brake fluid anymore than I saw the
need for my Grandmother to periodically flush my system with Castor Oil.
If the brake fluid in your vehicle is contaminated, you have a problem
that needs to be found and fixed BEFORE you change the fluid.
--
bill
Theory don't mean squat if it don't work.
Will Sill
everything that can be looked up or tested, recently wrote these
words:
>The seals on the master cylinder lid of all vehicles I've owned since
>1966 (can't remember the ones before that) have had full cover seals
>that are designed to flex with the varying level of the fluid, to
>prevent the sucking in of air and its contained moisture.
Me too. Chris seemed so emphatic (and is wrong very seldom on
technical assues) that I went out and looked. Sure enough. Mine are
made that way too.
>Unless the owner's manual for a specific vehicle says to do it, I see no
>reason to 'periodically' change the brake fluid anymore than I saw the
>need for my Grandmother to periodically flush my system with Castor Oil.
In well over 50 years and more than that many privately owned vehicles
I too have never ever changed the brake fluid other than as a part of
a restoration project after fitting new brake parts. And never yet
had a fluid-related problem. ANd as noted earlier, my manual doesn't
recommend changing brake fluid, despite page after page of other
recommendations.
>If the brake fluid in your vehicle is contaminated, you have a problem
>that needs to be found and fixed BEFORE you change the fluid.
That would certainly also be my POV.
Will KD3XR
Chris Bryant
<<..>>
>No, Chris, I am absolutely NOT "dead wrong" nor did I give dangerous
>advice. I challenged the misleading flat statement that " . . .the
>fluid aquires about 10% water per year.", and later pointed out that a
>sealed system doesn't permit moisture to be absorbed from the air.
And the links I gave explained that a braking system is not
sealed, and the brake fluid in that system can and will absorb
moisture
>The link you provided does NOT contradict anything I wrote. My owners
>manual (GMC) makes NO reference to changing brake fluid, and my
>11-year-old GMC pickup has almost certainly never had the fluid
>changed. (No need to unseal the system unless it starts leaking
>somewhere.)
>
I find it amazing that you have not had any brake work done in
11 years- but that is really irrelevant, as we are talking about a
Ford Class A chassis- and the official Ford recommendation is to
change the brake fluid every 2 years.
>Don't get me wrong - I DO agree that brake fluid absorbs moisture from
>the air - but not 10% per year, and definitely not inside a sealed
>system. Water in the fluid not only promotes rust but can lead to
>brake failure. People who have trouble with moisture inside their
>brake systems have it because the system was not kept sealed or was
>filled with contaminated fluid.
Wrong- if you had bothered to read any of the links provided,
you would realize that.
>
>Instead of throwing 11,500 pages at me, pony up some facts, Chris.
>
>And BTW brake FADING is more often than not caused by overheating of
>the lining material, and is not necessarily associated with water in
>the fluid.
Oh- I agree- especially when you qualify with "not
necessarily"- I would go as far as to guess that the majority of brake
fade is from the friction material being saturated with heat.
But.. bottom line, while I don't agree with the 10% a year
statement, Clark gave good sound advice, and you called it typical
usenet BS.
Chris Bryant
<<..>>
>While I won't argue about whether someone should periodically change
>their brake fluid (some should), or whether DOT 3 is hydroscopic (it
>is), I will say this:
>
>The only car I've ever owned that recommended changing the fluid was an
>88 Mazda.
>
>Neither my 96 Chevy PU nor my 83 Chevy PU manuals require, or recommend,
>periodically changing the brake fluid.
>
>I've never changed the fluid in my 83, and I've had no hydraulic system
>problems in the 19 years I've owned it.
But- have you had *no* work done on the brakes- usually a
brake job will entail adding fluid and bleeding the brakes. While not
a complete change, this will help.
>
>The seals on the master cylinder lid of all vehicles I've owned since
>1966 (can't remember the ones before that) have had full cover seals
>that are designed to flex with the varying level of the fluid, to
>prevent the sucking in of air and its contained moisture.
That's only one place the moisture can enter, and mine must
not be sealed as well as yours, as the level of my brake fluid has
dropped about 3/4 inch from normal wear in the last couple of years-
and I'm nearly certain that it isn't a vacuum in the top of the
reservoir.
>
>Unless the owner's manual for a specific vehicle says to do it, I see no
>reason to 'periodically' change the brake fluid anymore than I saw the
>need for my Grandmother to periodically flush my system with Castor Oil.
>
>If the brake fluid in your vehicle is contaminated, you have a problem
>that needs to be found and fixed BEFORE you change the fluid.
Bottom line is that the OP was talking about a Ford motor home
chassis, and Ford specifically recommends changing the brake fluid
every 2 years.
--
bill horne
>
> bill horne wrote:
>
> <<..>>
> >While I won't argue about whether someone should periodically change
> >their brake fluid (some should), or whether DOT 3 is hydroscopic (it
> >is), I will say this:
> >
> >The only car I've ever owned that recommended changing the fluid was an
> >88 Mazda.
> >
> >Neither my 96 Chevy PU nor my 83 Chevy PU manuals require, or recommend,
> >periodically changing the brake fluid.
> >
> >I've never changed the fluid in my 83, and I've had no hydraulic system
> >problems in the 19 years I've owned it.
>
> But- have you had *no* work done on the brakes- usually a
> brake job will entail adding fluid and bleeding the brakes. While not
> a complete change, this will help.
No. No one but myself has ever worked on any of my vehicle brakes. I
have, though, carried rotors and drums to someone to be turned.
> >The seals on the master cylinder lid of all vehicles I've owned since
> >1966 (can't remember the ones before that) have had full cover seals
> >that are designed to flex with the varying level of the fluid, to
> >prevent the sucking in of air and its contained moisture.
>
> That's only one place the moisture can enter, and mine must
> not be sealed as well as yours, as the level of my brake fluid has
> dropped about 3/4 inch from normal wear in the last couple of years-
> and I'm nearly certain that it isn't a vacuum in the top of the
> reservoir.
Brake fluid level drops as shoes, pads, drums, and rotors wear. My
manuals even caution about adding fluid when this could be the reason
for a lowered fluid level, as the thing could then be overfull when the
brakes are serviced.
And no, it's not a "vacuum" in the top of the reservoir. Have you looked
at the seal? The seal just moves down with the fluid level. The air
volume between the fluid and the seal remains essentially the same - no
"vacuum". At least none to speak of.
Disclaimer: I'm speaking of a 74 Chevy, an 83 Chevy, an 88 Mazda, and a
96 Chevy. I can't, with any confidence, say that all other vehicles use
the same type of seal.
> >Unless the owner's manual for a specific vehicle says to do it, I see no
> >reason to 'periodically' change the brake fluid anymore than I saw the
> >need for my Grandmother to periodically flush my system with Castor Oil.
> >
> >If the brake fluid in your vehicle is contaminated, you have a problem
> >that needs to be found and fixed BEFORE you change the fluid.
>
> Bottom line is that the OP was talking about a Ford motor home
> chassis, and Ford specifically recommends changing the brake fluid
> every 2 years.
And I said, "Unless the owner's manual for a specific vehicle says to do
it, I see no reason to 'periodically' change the brake fluid anymore
than I saw the
need for my Grandmother to periodically flush my system with Castor
Oil."
I still say it.
> --
> Chris Bryant
> Bryant RV Services- http://www.bryantrv.com
Will Sill
>Brake fluid level drops as shoes, pads, drums, and rotors wear. My
>manuals even caution about adding fluid when this could be the reason
>for a lowered fluid level, as the thing could then be overfull when the
>brakes are serviced.
Same here.
>And no, it's not a "vacuum" in the top of the reservoir. Have you looked
>at the seal? The seal just moves down with the fluid level. The air
>volume between the fluid and the seal remains essentially the same - no
>"vacuum". At least none to speak of.
Yup. Absolutely correct.
>Disclaimer: I'm speaking of a 74 Chevy, an 83 Chevy, an 88 Mazda, and a
>96 Chevy. I can't, with any confidence, say that all other vehicles use
>the same type of seal.
Also yup. And I can't help but wonder why at least some Ford manuals
recommend changing the fluid. And BTW never pretended people should
ignore the owners manual.
Will KD3XR
Will Sill
> And the links I gave explained that a braking system is not
>sealed, and the brake fluid in that system can and will absorb
>moisture
I saw NO link that explained THAT -- and if there was one, it is
incorrect for many brake systems. Mine (all GHM at the moment) are
all sealed.
> I find it amazing that you have not had any brake work done in
>11 years- but that is really irrelevant, as we are talking about a
>Ford Class A chassis- and the official Ford recommendation is to
>change the brake fluid every 2 years.
I didn't say that - I only said "my 11-year-old GMC pickup has almost
certainly never had the fluid changed. (No need to unseal the system
unless it starts leaking somewhere.)" If that was misleading,
sorry. I didn't buy it new. I have owned it for maybe 5 years, and
have had brake work that (as Bill Horne pointed out) does NOT require
adding fluid unless a leak occurs.
YOU may be talking about a particular Ford chassis - I was not and am
not. I said:
>Don't get me wrong - I DO agree that brake fluid absorbs moisture from
>>the air - but not 10% per year, and definitely not inside a sealed
>>system. Water in the fluid not only promotes rust but can lead to
>>brake failure. People who have trouble with moisture inside their
>>brake systems have it because the system was not kept sealed or was
>>filled with contaminated fluid.
You say:
> Wrong- if you had bothered to read any of the links provided,
>you would realize that.
Don't be a horse' behind - I DID read some of that stuff. Did YOU?
> But.. bottom line, while I don't agree with the 10% a year
>statement, Clark gave good sound advice, and you called it typical
>usenet BS.
Clark did NOT give good advice, and neither did you. GOOD advice is
accurate, None of us are perfect on these issues, and you've made
yerself look ridiculous on this issue.
Will KD3XR
Chris Bryant
>Chris Bryant wrote:
>>
>> bill horne wrote:
<<..>>
>Brake fluid level drops as shoes, pads, drums, and rotors wear. My
>manuals even caution about adding fluid when this could be the reason
>for a lowered fluid level, as the thing could then be overfull when the
>brakes are serviced.
>
>And no, it's not a "vacuum" in the top of the reservoir. Have you looked
>at the seal? The seal just moves down with the fluid level. The air
>volume between the fluid and the seal remains essentially the same - no
>"vacuum". At least none to speak of.
>
>Disclaimer: I'm speaking of a 74 Chevy, an 83 Chevy, an 88 Mazda, and a
>96 Chevy. I can't, with any confidence, say that all other vehicles use
>the same type of seal.
Bingo- Both of my vehicles have translucent BF reservoirs with
a small cap on them- if the seal was to expand to fill the void left
by the dropping fluid level, it would be clearly visible. In the old
style reservoirs, with the full size cover, I could see the seal
expanding that much, but not in the new style.
Which means that the seal isn't perfect, and air is entering.
<<..>>
>And I said, "Unless the owner's manual for a specific vehicle says to do
>it, I see no reason to 'periodically' change the brake fluid anymore
>than I saw the
>need for my Grandmother to periodically flush my system with Castor
>Oil."
>
>I still say it.
I disagree- but- a standard "daily driver" is unlikely to ever
stress the brakes as much as a vehicle loaded to near GVW- if you
*were* for some reason to need the full braking capacity of your
vehicles, you would not have it, as the boiling point of your brake
fluid is probably about 1/2 of the design point.
I simply think it is foolish to cheap out on something so
inexpensive, and potentially costly and dangerous. There are test kits
for moisture in brake fluid, but when it is only around $20 to have
the system flushed and refilled, I don't bother.
Chris Bryant
>Chris Bryant <Bryan...@cfl.rr.com> recently wrote these words:
>
>
>> And the links I gave explained that a braking system is not
>>sealed, and the brake fluid in that system can and will absorb
>>moisture
>
>I saw NO link that explained THAT -- and if there was one, it is
>incorrect for many brake systems. Mine (all GHM at the moment) are
>all sealed.
Well, let me see- the first link provided says:
"How does water get into the brake system? Moisture enters through
microscopic pores in the rubber brake hoses and seals, cracks in the
rubber brake hoses, leaks in the brake lines, and when the brake fluid
resevoir is opened (it does not take much for brake fluid to absorb
moisture, especially in a place like Florida where there tends to be a
great deal of humidity in the air)."
The second link says:
"The amount of moisture in brake fluid definitely affects its
performance. The big problem is it is absorbs moisture quickly. Over a
relatively short period of time brake fluid will absorb moisture from
the air. SAE field tests have shown that the average one year old car
has 2% moisture in the fluid. A random test of vehicles in the U.S.
showed an average water content of 2.6% for vehicles with an average
age of 8 years. And 25% of these vehicles had water content greater
than 4%. "
The list goes on and on.
>
>YOU may be talking about a particular Ford chassis - I was not and am
>not. I said:
This whole thread is about a particular Ford chassis- and that
is what Clarke was responding to.
>
>>Don't get me wrong - I DO agree that brake fluid absorbs moisture from
>>>the air - but not 10% per year, and definitely not inside a sealed
>>>system. Water in the fluid not only promotes rust but can lead to
>>>brake failure. People who have trouble with moisture inside their
>>>brake systems have it because the system was not kept sealed or was
>>>filled with contaminated fluid.
>
>You say:
>> Wrong- if you had bothered to read any of the links provided,
>>you would realize that.
>
>Don't be a horse' behind - I DID read some of that stuff. Did YOU?
Yep.
>
>
>> But.. bottom line, while I don't agree with the 10% a year
>>statement, Clark gave good sound advice, and you called it typical
>>usenet BS.
>
>Clark did NOT give good advice, and neither did you. GOOD advice is
>accurate, None of us are perfect on these issues, and you've made
>yerself look ridiculous on this issue.
I repeat- Clark gave good advice, you called it typical usenet
BS. It is bad advice and dangerous to tell people that changing brake
fluid is un needed. It is a vital maintenance item on large motor
homes- something that should be done at least every 5 years, and Ford
specifies every 2 years.
With that, I'm sure you will want the last word- I cannot make
it much more plain.
Be my guest.
Alan King
>a standard "daily driver" is unlikely to ever
>stress the brakes as much as a vehicle loaded to near GVW- if you
>*were* for some reason to need the full braking capacity of your
>vehicles, you would not have it, as the boiling point of your brake>fluid is
probably about 1/2 of the design point.
An interesting little debate to wake up to this morning. A lot of the
discussion has centered around whether the system is "sealed" or not. Well,
there ain't no such thing as a perfectly sealed system when there are moving
parts involved. Second, air/moisture entering the system generally gets in at
the wheel cylinders, not at the master cylinder.
Theoretically, all vehicles should have the brake fluid changed at some
interval, but in practice passenger vehicles and light trucks are driven
enough and get brake work done often enough to make this not an issue. But
larger vehicles like motorhomes, with significantly larger volumes of brake
fluid, that sit for long periods of time and may not get brake work done for
years definitely need the fluid changed periodically.
Alan King
Will Sill
this. He said:
>>> And the links I gave explained that a braking system is not
>>>sealed, and the brake fluid in that system can and will absorb
>>>moisture
So, I replied that:
>>I saw NO link that explained THAT -- and if there was one, it is
>>incorrect for many brake systems. Mine (all GM at the moment) are
>>all sealed.
(Which was true - I did NOT see such a link tho I scanned several of
those offered)
Sez he:
> Well, let me see- the first link provided says:
>
>"How does water get into the brake system? Moisture enters through
>microscopic pores in the rubber brake hoses and seals, cracks in the
>rubber brake hoses, leaks in the brake lines, and when the brake fluid
>resevoir is opened (it does not take much for brake fluid to absorb
>moisture, especially in a place like Florida where there tends to be a
>great deal of humidity in the air)."
OK, I did not read that particular verbiage, and if I had I woulda
barfed because it is out of any reasonable context. Words on my
screen don't constitute facts, but I now see why you might believe
some of this. Allow me to opine that the microscopic "pore" thing is
almost certainly pure bafflegab, and the rest are either dangerous
DEFECTS or deliberate opening of the seal to add fluid. Air does not
enter a closed system in opposition to internal pressure - and there
is always SOME internal pressure (small though it is at rest) due to
the weight of the fluid. The parenthetical remark about how easy brake
fluid takes on moisture is probably valid but totally irrelevant in a
sealed, non-defective, unopened system.
> The second link says:
>
>"The amount of moisture in brake fluid definitely affects its
>performance. The big problem is it is absorbs moisture quickly. Over a
>relatively short period of time brake fluid will absorb moisture from
>the air.
Fine - don't disagree with that.
>SAE field tests have shown that the average one year old car
>has 2% moisture in the fluid. A random test of vehicles in the U.S.
>showed an average water content of 2.6% for vehicles with an average
>age of 8 years. And 25% of these vehicles had water content greater
>than 4%. "
Very interesting - if true - but a helluva lot different than a claim
that the fluid absorbs 10% moisture per year. If THAT were true, my
truck would be 110% water, fer cryin' out loud!
> This whole thread is about a particular Ford chassis- and that
>is what Clarke was responding to.
YOU may think "brake fading" and the moisture-in-fluid issue is only
a Ford topic. I don't.
As I said:
>>Clark did NOT give good advice, and neither did you. GOOD advice is
>>accurate, None of us are perfect on these issues, and you've made
>>yerself look ridiculous on this issue.
Now Chris claims:
> I repeat- Clark gave good advice, you called it typical usenet
>BS. It is bad advice and dangerous to tell people that changing brake
>fluid is un needed. It is a vital maintenance item on large motor
>homes- something that should be done at least every 5 years, and Ford
>specifies every 2 years.
Where did I tell people that changing brake fuid is unnecessary? I
did say I have not done it, and I did say my owner manual does not
recommend it. I also challenged the "10%" crap because it was dead
wrong, and stated (and stand by) "Brake fluid in a sealed container or
system does NOT absorb moisture." I certainly do take the
conservative POV that one ought to change brake fluid in a vehicle
that has brakle system defects or failures, or vehicles for which
changing fluids is recommended. But I also say that if it ain't
broke, don't 'fix' it. None of my brakes are broke.
All your arguments seem to center around either
1) a mistaken understanding of what "sealed" means.
2) an erroneous belief that I'm against changing fluid when
appropriate OR recommended by the manufacturer; or
3) a desire to argue
Will Sill
>An interesting little debate to wake up to this morning. A lot of the
>. . . air/moisture entering the system generally gets in at
>the wheel cylinders, not at the master cylinder.
Would you mind explaining the basis for that statement?
Will KD3XR
bill horne
> Where did I tell people that changing brake fuid is unnecessary? I
> did say I have not done it, and I did say my owner manual does not
> recommend it. I also challenged the "10%" crap because it was dead
> wrong, and stated (and stand by) "Brake fluid in a sealed container or
> system does NOT absorb moisture." I certainly do take the
> conservative POV that one ought to change brake fluid in a vehicle
> that has brakle system defects or failures, or vehicles for which
> changing fluids is recommended. But I also say that if it ain't
> broke, don't 'fix' it. None of my brakes are broke.
>
> All your arguments seem to center around either
> 1) a mistaken understanding of what "sealed" means.
> 2) an erroneous belief that I'm against changing fluid when
> appropriate OR recommended by the manufacturer; or
> 3) a desire to argue
>
> Will KD3XR ---- the Curmudgeon of Sill Hill
Here's some more on that from Chris's links:
From AAA:
---------------------------------------------------
Should Brake Fluid Be Changed?
Vehicle manufacturers are about evenly divided on whether or not the
brake system should be flushed periodically and refilled with fresh
fluid. All of the manufacturers who call for brake fluid changes are
import carmakers, about evenly divided between Asian and European. None
of the domestic Big-Three manufacturers calls for periodic brake fluid
changes. When specified, change intervals vary from as often as every
12 months or 15,000 miles to as infrequently as every 60,000 miles. The
manufacturer's maintenance schedule for your vehicle is your best guide.
----------------------------------------
From the same AAA, different page:
----------------------------------------
Unfortunately, when you need the brakes the most, you may not have any.
If the fluid is flushed every two years, the moisture will be removed
from the system and the boiling point will be returned to an acceptable
level. So, not only will flushing the brake system prevent corrosion
and premature wear of hydraulic components, but can also keep your
brakes from going to the floor when they get hot!
----------------------------------------
From "thebrakeman":
----------------------------------------
Since the brake fluid can only absorb approximately 2% moisture, it
stops here.
----------------------------------------
I concede that the search on 'brake fluid moisture' results in a
preponderance of links that say "change your brake fluid", but most of
those sites seem to be in the business of providing product or service.
Bad fluid can cause bad brakes. Bad brakes can cause bad things to
happen. Bad things happening can cause law suits. Unless anyone
disagrees with that, my question is then - Why doesn't GM require, or
recommend, the periodic changing of brake fluid? If for no other reason,
to cover their ass.
What I'm not going to do is take an unbroken vehicle to a mechanic for a
transfusion, and risk an unsanitary transfusion which could result in my
unbroken brakes becoming broken.
I once had whiteknuckle brake fade with my 83 and TT (no brakes on that
TT) going down a mountain north of San Francisco. The next day, I went
to the hobby shop at a nearby AFB to find the problem. Pads and shoes,
it was. My fault - should have replaced them before we started the trip.
I did not replace the fluid. That was in 1987, and I've had no problem
with the brakes - other than having to replace pads and shoes.
So, if I should have a brake problem, unless I determine the problem is
bad brake fluid, I'm going to go with "The manufacturer's maintenance
schedule for your vehicle is your best guide."
--
bill
Theory don't mean squat if it don't work.
HHamp5246
>So, if I should have a brake problem, unless I determine the problem is
>bad brake fluid, I'm going to go with "The manufacturer's maintenance
>schedule for your vehicle is your best guide."
That's what Chris said...... the motohome chassis manufacturer maintenence
schedule says to change it.
Hunter
Will Sill
>Here's some more on that from Chris's links:
>
>From AAA:
>---------------------------------------------------
>Should Brake Fluid Be Changed?
>
>Vehicle manufacturers are about evenly divided on whether or not the
>brake system should be flushed periodically and refilled with fresh
>fluid. All of the manufacturers who call for brake fluid changes are
>import carmakers, about evenly divided between Asian and European. None
>of the domestic Big-Three manufacturers calls for periodic brake fluid
>changes.
[I guess AAA doesn't consider Ford a domestic?]
>>When specified, change intervals vary from as often as every
>12 months or 15,000 miles to as infrequently as every 60,000 miles. The
>manufacturer's maintenance schedule for your vehicle is your best guide.
>----------------------------------------
>
>From the same AAA, different page:
>----------------------------------------
>Unfortunately, when you need the brakes the most, you may not have any.
>If the fluid is flushed every two years, the moisture will be removed
>from the system and the boiling point will be returned to an acceptable
>level. So, not only will flushing the brake system prevent corrosion
>and premature wear of hydraulic components, but can also keep your
>brakes from going to the floor when they get hot!
>----------------------------------------
>
>From "thebrakeman":
>----------------------------------------
>Since the brake fluid can only absorb approximately 2% moisture, it
>stops here.
>----------------------------------------
Not too hard to see why Chris is confused, since the "data" (may I use
that term to describe a mixture of good stuff, bafflegab, and total
hogwash?) is - at best - contradictory. When I scanned through the
stuff, I concluded that the people whe developed the links had as
little expertise & authority as any usenet source!
Bill sez:
>I concede that the search on 'brake fluid moisture' results in a
>preponderance of links that say "change your brake fluid", but most of
>those sites seem to be in the business of providing product or service.
>
>Bad fluid can cause bad brakes. Bad brakes can cause bad things to
>happen. Bad things happening can cause law suits. Unless anyone
>disagrees with that, my question is then - Why doesn't GM require, or
>recommend, the periodic changing of brake fluid? If for no other reason,
>to cover their ass.
My own view on that, based on personal experience and (gasp) whatever
engineering expertise I have, is that it simply is NOT even remotely
necessary in anything approaching normal use. As I've opined
several times, a properly sealed system is simply not going to take in
moisture - never has that I know about in any vehicle I've ever owned
- but I concede I don't presently own any Fords - big or little.
>What I'm not going to do is take an unbroken vehicle to a mechanic for a
>transfusion, and risk an unsanitary transfusion which could result in my
>unbroken brakes becoming broken.
>
>I once had whiteknuckle brake fade with my 83 and TT (no brakes on that
>TT) going down a mountain north of San Francisco. The next day, I went
>to the hobby shop at a nearby AFB to find the problem. Pads and shoes,
>it was. My fault - should have replaced them before we started the trip.
>I did not replace the fluid. That was in 1987, and I've had no problem
>with the brakes - other than having to replace pads and shoes.
>
>So, if I should have a brake problem, unless I determine the problem is
>bad brake fluid, I'm going to go with "The manufacturer's maintenance
>schedule for your vehicle is your best guide."
Me too, even though Chris seems to think that's "dangerous advice".
[It feels kinda strange to be accused of offering reckless counsel.
My usual hate mail comes from bozos who think I am much too
conservative because I advise against overloading, over-inflating,
etc]
Will KD3XR
bill horne
If it says it for that specific vehicle, that's correct, but he also
said some other things about brake systems with which I took/take issue.
And if Ford is one of the "domestic Big Three", then AAA's - "None of
the domestic Big-Three manufacturers calls for periodic brake fluid
changes" contradicts even that statement. But I'd go with The Manual for
The Vehicle, regardless of what AAA, thebrakeman, or anyone else says.
But since I've never paid for a brake job, I do have two questions for
those of you who pay some establishment to just replace your pads and
shoes - When you have your pads/shoes replaced, is flushing and bleeding
the hydraulics part of the Standard Procedure, or is it optional,
mandatory, persuasively optional, or what? And how much does it cost?
Just Me
>
> If it says it for that specific vehicle, that's correct, but he also
> said some other things about brake systems with which I took/take
> issue. And if Ford is one of the "domestic Big Three", then AAA's -
> "None of the domestic Big-Three manufacturers calls for periodic brake
> fluid changes" contradicts even that statement. But I'd go with The
> Manual for The Vehicle, regardless of what AAA, thebrakeman, or anyone
> else says.
>
> But since I've never paid for a brake job, I do have two questions for
> those of you who pay some establishment to just replace your pads and
> shoes - When you have your pads/shoes replaced, is flushing and
> bleeding the hydraulics part of the Standard Procedure, or is it
> optional, mandatory, persuasively optional, or what? And how much does
> it cost?
>
Bill,
It's always been a part of the job, or so they tell me [on the
paperwork].
Of course, they *could* just be padding the number of hours but,
considering that this would have to be an "Industry Standard" practice
for both dealerships and independent mechanics, I lean towards the SOP
position.
Since I've never had an itemized pricing for the procedure, I can't
help you there.
bill horne
> [It feels kinda strange to be accused of offering reckless counsel.
> My usual hate mail comes from bozos who think I am much too
> conservative because I advise against overloading, over-inflating,
> etc]
>
> Will KD3XR
Yeah, but but but - are you adding an extra few ounces to your MC for
improved performance?
bill horne
Is turning the rotors and drums SOP also? In any event, what's a
Standard Brake Job cost (ballpark) these days, and what does it include?
Chris Bryant
Will Sill wrote:
<<snip>>
>Not too hard to see why Chris is confused, since the "data" (may I use
>that term to describe a mixture of good stuff, bafflegab, and total
>hogwash?) is - at best - contradictory. When I scanned through the
>stuff, I concluded that the people whe developed the links had as
>little expertise & authority as any usenet source!
So- you didn't read any of the info I provided links to- you
scanned, and because it goes against your opinion, you dismiss it as
bafflegab.
I am not confused at all- you are wrong, and I am right, I
have provided ample evidence, and you have provided your opinion.
>
>Bill sez:
>>I concede that the search on 'brake fluid moisture' results in a
>>preponderance of links that say "change your brake fluid", but most of
>>those sites seem to be in the business of providing product or service.
>>
>>Bad fluid can cause bad brakes. Bad brakes can cause bad things to
>>happen. Bad things happening can cause law suits. Unless anyone
>>disagrees with that, my question is then - Why doesn't GM require, or
>>recommend, the periodic changing of brake fluid? If for no other reason,
>>to cover their ass.
>
>My own view on that, based on personal experience and (gasp) whatever
>engineering expertise I have, is that it simply is NOT even remotely
>necessary in anything approaching normal use. As I've opined
>several times, a properly sealed system is simply not going to take in
>moisture - never has that I know about in any vehicle I've ever owned
>- but I concede I don't presently own any Fords - big or little.
Your opinion is incorrect, plain and simple.
>
>>What I'm not going to do is take an unbroken vehicle to a mechanic for a
>>transfusion, and risk an unsanitary transfusion which could result in my
>>unbroken brakes becoming broken.
>>
>>I once had whiteknuckle brake fade with my 83 and TT (no brakes on that
>>TT) going down a mountain north of San Francisco. The next day, I went
>>to the hobby shop at a nearby AFB to find the problem. Pads and shoes,
>>it was. My fault - should have replaced them before we started the trip.
>>I did not replace the fluid. That was in 1987, and I've had no problem
>>with the brakes - other than having to replace pads and shoes.
>>
>>So, if I should have a brake problem, unless I determine the problem is
>>bad brake fluid, I'm going to go with "The manufacturer's maintenance
>>schedule for your vehicle is your best guide."
>
>Me too, even though Chris seems to think that's "dangerous advice".
>
Yes, I know it is dangerous advice- bottom line.
>[It feels kinda strange to be accused of offering reckless counsel.
>My usual hate mail comes from bozos who think I am much too
>conservative because I advise against overloading, over-inflating,
>etc]
>
>Will KD3XR
I'm somewhat amazed that in your career as a "Safety
Engineer". you never ran across an example of the "recommended
maintenance" to be inadequate.
We are talking about large motor homes here- not class "B"s,
not daily drivers- though personally, I have the brake fluid flushed
and changed every 5 years, if I do not need other brake service before
then- and I drive few enough miles now that I usually do not need
pads, etc.
Funny thing- my 9AM appointment couldn't make it in this
morning because his brakes all were dragging.
To recap- you have given bad advice, based solely on your
opinion and (dare I say it) theory, which in the real world doesn't
pan out. I doubt anyone would take your advice- but think about what
would happen if someone took a motor home in for service, was told he
should have his brake fluid flushed, and based upon what he read from
you, believed that it was a mere attempt at charging for an un needed
service.
I am not confused- I don't feel a need to argue, and I am
certain that I will read some snipes from you in the future in totally
unrelated threads- as is your style.
Tom
of pads.
$150 parts and labor
Tom
Will Sill
>But since I've never paid for a brake job, I do have two questions for
>those of you who pay some establishment to just replace your pads and
>shoes - When you have your pads/shoes replaced, is flushing and bleeding
>the hydraulics part of the Standard Procedure, or is it optional,
>mandatory, persuasively optional, or what? And how much does it cost?
I have recently started having brake work done by others, and no
mention has been made of flushing/bleeding. All that's been done is
shoe/pad replacement. At this shop it is clearly optional. But then
we currently have all GM vehciles with a sealed hydraulinc system.
Will KD3XR
Will Sill
>*Sigh*
For someone who doesn't feel the need to argue, you have a
near-Osbornian knack for making a mountain out of a molehill. And for
a guy who is almost always courteous & helpful, you've made a complete
ass of yourself on this issue.
I've said all I think needs to be said on this issue, and saying it
again will serve no purpose. But I will summarize by endorsing
(enthusiastically) the idea of flushing brake fluid:
1) When recommended by the manufacturer of the vehicle
2) Whenever the system is opened up by a leak or for replacement of
hydraulic parts (hoses, cylinders).
And I will continue to believe that a sealed system with no defects
does NOT require flushing except as noted above.
BTW, Chris - how much water can brake fluid absorb - and how do you
know for sure?
Will KD3XR ---- the Curmudgeon of Sill Hill
David Osborn
>I have recently started having brake work done by others, and no
>mention has been made of flushing/bleeding. All that's been done is
>shoe/pad replacement. At this shop it is clearly optional. But then
>we currently have all GM vehciles with a sealed hydraulinc system.
"Sealed" is an interesting term. Most of us -- but obviously not Mr. Sill --
are aware that a gas will pass through numerous barriers that hold a liquid.
In other words, "sealed" for a liquid doesn't necessarily mean "sealed" for a
gas.
--
David, N8DO; FMCA 147762
djosborn at aol dot com
Jim
years I only replaced fluid then I had a 90 Olds with ABS turn on the
ABS brake idiot light ; the brakes worked fine until you forced the ABS
to function. Then it did strange things. Tried all kinds of things
except replacing the $600 or $1000 parts. The dealer ( a real good one
) said that all they could do was take a guess on those expensive parts.
It was not fixed when I traded it. The best mechanic I have ever
known said that most of the new ABS systems were so sensitive that you
should replace the brake fluid every two years or so and I both trust
and believe him. For the minor cost involved I will replace the fluid
in my cars and the MH. It can't hurt and those parts are expensive !!!
--
Jim & Barb Bruckert
Phooey & Pounce
01 Winnie 35U
& Tracker toad
SKP 74448
Lon VanOstran
> Aha! Anoither brilliant bit of 'wisdom' from usenet. BS is still BS
> when it appears in print. Brake fluid in a sealed container or
> system does NOT absorb moisture.
Then why do the experts suggest changing brake fluid every 3 years?
Lon
Mark
Lon, I don't think you'll change Will's mind on this... since he'll now ask
you: "What experts?".
I, for one, do change it regularly.. wouldn't believe the crud that comes out.
The fluid coming out is inevitably dark and/or murky.
Mark
Lon VanOstran
Maybe Will won't consider them experts, but the tech columns in Trailer
Life, Motorhome, Highways, and Family Motor coach have all suggested
changing brake fluid to prevent lowering of the boiling point via water
contamination. Most suggest every 3 years, while Ford recommends every 2
years.
Now, with Chris Bryant chiming in I will go with changing it.
Lon
Will Sill
Can't answer your question though since you've been away there have
been a raft of posts on this problem that should be sufficient to
clarify my POV. If you check this out closely you'll find that the
"experts" are not even close to being unanimous. If your owner
manual recommends it, do it.
Will KD3XR
George Becker
1) Every time I flushed out the brake fluid after 5 years or so it came out
very dark and dirty. Justification enough for me to change it earlier. This
was in motorcycles and my two Corvettes.
2) Is Will Sill trying to force one of the most knowledgeable and helpful
contributors to this newsgroup to leave like some others have done, not
needing the aggravation?
Sincerely
George W Becker
gw...@cinci.rr.com
1999 Country Coach Intrigue #10700
Chris Bryant
<<..>>
>BTW, Chris - how much water can brake fluid absorb - and how do you
>know for sure?
That's an easy one- it can absorb enough moisture that it no
longer operates with the design characteristics, particularly boiling
point, and corrosion resistance.
Furthermore- it will reach this point far before (in time and
capacity) it reaches the saturation point.
I know it because it is somewhat common knowledge.
Will Sill
>Will Sill wrote:
><<..>>
>>BTW, Chris - how much water can brake fluid absorb - and how do you
>>know for sure?
>
> That's an easy one- it can absorb enough moisture that it no
>longer operates with the design characteristics, particularly boiling
>point, and corrosion resistance.
> Furthermore- it will reach this point far before (in time and
>capacity) it reaches the saturation point.
>
> I know it because it is somewhat common knowledge.
Just wondered which of the conflicting sources you considered
authentic, and frankly I was kinda jerking yer chain because I doubt
there IS a source that is meaningful. The figures provided in the
links you posted are (not to put a fine point on are) wildly
inconsistent, though all dramatically BELOW the 10% per year cited by
the post I challenged.
BTW I agree that brake fluid with water in it sux. In case you
thought otherwise.
Will KD3XR
bill horne
> BTW I agree that brake fluid with water in it sux.
> Will KD3XR
Ah! So that's what causes the vacuum.
Will Sill
>Will Sill wrote:
>
>> BTW I agree that brake fluid with water in it sux.
>Ah! So that's what causes the vacuum.
Hehehe! If there is one, that would be the cause!
Will KD3XR
Allen Wood
thread about brake fade/water contamination and have been pushed into
dragging out my 1995 veresion of the SAE International Standards Handbooks.
Below is what I found on this subject.
(Volume 2) 2525.62 3.3.3 - Water Contamination -j1703 motor vehicle brake
fluids are hygroscopic and absorb moisture when exposed to the atmosphere
and in service. Water contamination from any source including mechanical or
accidental additions of free water, will appreciably lower the original
boiling point of the brake fluid and increase its viscosity at low ambient
temps. Water contamination my cause corrosion of brake cylinder bores and
pistons, and may seriously affect the braking efficiency and safety of the
braking system
(Volume 2) 25.63 7.2 - Replacement of brake fluid in the braking system -
Brake fluids inthe motor vehicle braking system can become contaminated.
Whenever wheel cylinders and/or calipers are removed for inspection,
reconditioning or replacement, or when contamination is syspected, it is
strongly recommended that the system be flushed and refilled. Periodic
changes of fluid in aging vehicles are not recommended unless wheel
cylinders and calipers are disconnected to prevent and dirt, sludge, or
abrasive materials in the the system from being flushed into them.
Otherwise they may cause scoring or scuffing of pistions, bores, cups, or
seals, with possible leakage and system failure.
This is what I have found, there is a great deal of information on this
subject in the SAE standard but I have grown very tired of looking it up and
even more tired of this tread. My thoughts are that people are generally
going to believe what they believe and no amount of information is going to
change their mind.
Allen Wood
"Will Sill" <wi...@epix.net> wrote in message
news:5c1qgu8eb5cqaqo5d...@4ax.com...
Alan King
>>An interesting little debate to wake up to this morning. A lot of the
>>. . . air/moisture entering the system generally gets in at
>>the wheel cylinders, not at the master cylinder.
>
>Would you mind explaining the basis for that statement?
The wheel cylinders are where the relative motion is, where the large swings in
temperature are and, most importantly, where most of the water exposure occurs.
Thats sorta why wheel cylinders and calipers tend to get rustier than master
cylinders.
Alan King
Will Sill
of the SAE International Standards Handbooks, including the following
bit of wisdom:
>. . .Water contamination from any source including mechanical or
>accidental additions of free water, will appreciably lower the original
>boiling point of the brake fluid and increase its viscosity at low ambient
>temps. Water contamination my cause corrosion of brake cylinder bores and
>pistons, and may seriously affect the braking efficiency and safety of the
>braking system
AFAIK everyone agrees with that. What a few folks have a LOT of
anguish about would be this:
>Whenever wheel cylinders and/or calipers are removed for inspection,
>reconditioning or replacement, or when contamination is suspected, it is
>strongly recommended that the system be flushed and refilled. Periodic
>changes of fluid in aging vehicles are not recommended unless wheel
>cylinders and calipers are disconnected to prevent and dirt, sludge, or
>abrasive materials in the the system from being flushed into them.
Couldn't have said it better myself.
I didn't write the standard but I like it. Not just because I agree
with it, but because it makes perfect sense to anyone who understands
how closed, unvented hydraulic systems work.
Will KD3XR
Will Sill
>The wheel cylinders are where the relative motion is, where the large swings in
>temperature are and, most importantly, where most of the water exposure occurs.
>
>Thats sorta why wheel cylinders and calipers tend to get rustier than master
>cylinders.
Fine, but as a GM engineer, how (if you can) do you explain the
absence of reference to changing brake fluid in GM manuals? Though I
have found several things to gripe about in GM vehicles, bad brake
fluid is not among them.
Will KD3XR
Will Sill
Except for a spontaneous cracked windshield and a fuel level gauge
problem, our '99 GMC Savana 3500 (basis for our class B) has been
virtually trouble free for over 58k miles.
But with each trip I am more annoyed by the need to use the brakes far
too much (IMO). It may even be a (gasp) safety issue, and I covet
yer advice. Here is my take on the problem:
In virtually all driving situations, the throttle does not close
promptly to idle mode when I remove my foot from the accelerator.
There seems to be a period of several seconds during which it
maintains a part throttle position before the engine goes to idle
mode. To avoid fighting throttle with brakes I must anticipate the
need to slow for several seconds.
My mechanic - an excellent GM-trained guy - tells me that's the way
they are programmed. He is usually right but not always and I wonder
why the engine can't be programmed to go directly to idle mode when I
touch the brakes - even if not just when backing off the accelerator.
Any ideas, facts, or flames?
Will KD3XR
Mark
>they are programmed. He is usually right but not always and I wonder
>why the engine can't be programmed to go directly to idle mode when I
>touch the brakes - even if not just when backing off the accelerator.
>
>Any ideas, facts, or flames?
>
>Will KD3XR
This has been around for quite some time. If's possible that one of the
mechanical parts is binding or wearing out with age and not responding as fast
as it should.. though on a '99, it should be unlikely. Possibly something is
out of adjustment in the linkages.
IIRC, these popped up back in the 80's with throttle body injectors. They did
several thing. When the foot is taken off the throttle, some of the emissions
went sky-high and this brought those down by allowing the fuel to be combusted
rather than dumped out the tailpipe. (Techincally, the throttle plate responded
faster than the fuel control so fuel would continue spraying for a short period
and "flood" the engine). Also, on some, at slow speeds, in low gear, a quick
release of the throttle would often cause an excess of "reverse torque' in some
of the trannys. I think it was Ford who had the tranny issue, though it might
have been the Turbo-350's... don't remember who.
A couple of us played with the computers and injection systems with racecars
and generally found the thing (throttle "slow down" dealy..forget the tech
term) useless in that application, but the electronics and mechanicals had to
be hooked up for the computer to work properly....but there was a way around
that...
I'm sure Alan can tell us more... I'm just an old shade-tree mech who doesn't
play with 'em anymore...
Mark
Bubba
the throttle. In my case, the throttle would not release until the wheels
were just about stopped. The service manager told me that was the way a
fuel injected vehicle behaved. I asked him if he could change out the
computer and test it that way. He said the computer checked good and he
could not switch computers. I had the car in the shop 14 times in 12 months
for various problems. I will say that GM was more than willing to cover the
repair for this problem no matter how long it took, even if out of warranty.
The problem was that I felt that the life of the brakes and quite possibly
the occupants would be shortened, if I continued to drive the vehicle.
Finally, I parked it in their lot with a long letter and the keys and told
them what they could do with it. Almost a year later a GM rep called me to
tell me that they found that the computer was bad. He wanted to know what I
wanted to do now that they had repaired the car. I thanked him for his call
and told him exactly what he could do with it.
Mickey
Chris Bryant <Bryan...@cfl.rr.com> wrote in message
news:bsjngu4mcomhhivlc...@4ax.com...
SNIP
>
> I'm somewhat amazed that in your career as a "Safety
> Engineer". you never ran across an example of the "recommended
> maintenance" to be inadequate.
>
> We are talking about large motor homes here- not class "B"s,
> not daily drivers- though personally, I have the brake fluid flushed
> and changed every 5 years, if I do not need other brake service before
> then- and I drive few enough miles now that I usually do not need
> pads, etc.
>
> Funny thing- my 9AM appointment couldn't make it in this
> morning because his brakes all were dragging.
>
> To recap- you have given bad advice, based solely on your
> opinion and (dare I say it) theory, which in the real world doesn't
> pan out. I doubt anyone would take your advice- but think about what
> would happen if someone took a motor home in for service, was told he
> should have his brake fluid flushed, and based upon what he read from
> you, believed that it was a mere attempt at charging for an un needed
> service.
> I am not confused- I don't feel a need to argue, and I am
> certain that I will read some snipes from you in the future in totally
> unrelated threads- as is your style.
>
>
> --
> Chris Bryant
> Bryant RV Services- http://www.bryantrv.com
I'm jumping in here a little late but have been camping for a few days.
I think Will is suffering from what we all do from time to time and that is
the everyone's world is the same as we experience. Very bad advice can be
given when we are thinking this way. I would bet Will's old GM van has a
cast iron master cylinder including fluid reservoir. This is a rarity in
today's world with many/most vehicles having plastic, nylon, reservoirs.
Nylon is VERY hydroscopic so from a "sealed" standpoint, it AIN"T. Since I
don't deal with plastics daily anymore I don't recall the exact % of water @
saturation but I can't forget that nylon grows/shrinks 1/32" per inch from
bone dry to fully saturated and at saturation, the water content is in the
double digit range.
Since a Ford product was the subject of the original post I will add that my
89 E350 chassis has a aluminum master cylinder with a plastic reservoir.
Maybe that is the reason Ford recommends the fluid change as stated in Bill
Horne's first post in this thread. This is also likely the reason import
auto Co's are are more likely to recommend fluid change on a reg basis.
When is the last time you saw an all metal master cylinder on an import?
And if it maters, I'm siding with Chris on his comments because for many, it
is the right answer to be offering others.
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.370 / Virus Database: 205 - Release Date: 6/5/02
Big....@hotmail.com
My 91 Olds '98 says to change the brake fluid also. (One of the big
three).
Big John
On Sat, 15 Jun 2002 18:41:53 -0400, bill horne <red...@rye.net> wrote:
>HHamp5246 wrote:
>>
>> Bill wrote:
>> >So, if I should have a brake problem, unless I determine the problem is
>> >bad brake fluid, I'm going to go with "The manufacturer's maintenance
>> >schedule for your vehicle is your best guide."
>>
>> That's what Chris said...... the motohome chassis manufacturer maintenence
>> schedule says to change it.
>>
>> Hunter
>
>If it says it for that specific vehicle, that's correct, but he also
>said some other things about brake systems with which I took/take issue.
>And if Ford is one of the "domestic Big Three", then AAA's - "None of
>the domestic Big-Three manufacturers calls for periodic brake fluid
>changes" contradicts even that statement. But I'd go with The Manual for
>The Vehicle, regardless of what AAA, thebrakeman, or anyone else says.
>
>But since I've never paid for a brake job, I do have two questions for
>those of you who pay some establishment to just replace your pads and
>shoes - When you have your pads/shoes replaced, is flushing and bleeding
>the hydraulics part of the Standard Procedure, or is it optional,
>mandatory, persuasively optional, or what? And how much does it cost?
>
Big....@hotmail.com
A 99% direct quote on my system.
Big John
Big....@hotmail.com
When it comes out milkey, you know you had a lot of water in the
system also.
Big John
bill horne
>
> Bill
>
> My 91 Olds '98 says to change the brake fluid also. (One of the big
> three).
>
> Big John
When are you supposed to change it?
Mark
>
>When it comes out milkey, you know you had a lot of water in the
>system also.
>
>Big John
Never saw milky... just dirty and dark looking. Even cars that got the fluid
changed once a year (major brake work on a race car), it was always darker than
the new stuff.
Mark
bill horne
Maybe you should guess some more. Both my 83 and my 96 Chevy PU have a
plastic (or composite) reservoir and an aluminum (or composite) master
cylinder, and I still haven't found anything in the owner's manuals or
service manuals for either that recommends or requires periodic changing
of brake fluid.
> And if it maters, I'm siding with Chris on his comments because for many, it
> is the right answer to be offering others.
I'm siding with the manufacturers. If your manual says change it
periodically, do so. If it doesn't say change it, do whatever you want.
But you - or anyone else - have yet to convince me that everybody should
change their brake fluid every couple of years.
> ---
bill horne
My 96 does the same thing. Always has. It appears to be designed to do
that, and it annoys the hell out of me, too. When I go to the mountains,
I disconnect the Throttle Position Sensor (TPS). This gives me immediate
engine braking when I let off the throttle. It also gives me a slightly
rough idle, but I can live with that in exchange for engine braking
while in the mountains.
Will Sill
>I think Will is suffering from what we all do from time to time and that is
>the everyone's world is the same as we experience. Very bad advice can be
>given when we are thinking this way. I would bet Will's old GM van has a
>cast iron master cylinder including fluid reservoir.
WHen it comes to suffereing, I don't do much! You'd lose some serious
money with your stupid bet. My "old" GM van is a '99, and like my
other GM vehciles, it has a sealed translucent reservoir and an owners
manual that does NOT mention changing brake fluid.
What's more, I have NOT recommended that people ignore THEIR manuals,
when they get different advice from them.
> . . . .many/most vehicles having plastic, nylon, reservoirs.
>Nylon is VERY hydroscopic so from a "sealed" standpoint, it AIN"T.
Very interesting but almost certainly untrue. If you are trying to
say that moisture gets into the fluid through the walls of the
reservoir - no manner what plastic it's made of - you are going to
have to offer some credible proof. I think you are blowing smoke.
> Since I
>don't deal with plastics daily anymore I don't recall the exact % of water @
>saturation but I can't forget that nylon grows/shrinks 1/32" per inch from
>bone dry to fully saturated and at saturation, the water content is in the
>double digit range.
First you'd have to show that nylon is the material used in brake
reservoirs. I don't KNOW that it is or isn't, but frankly I doubt
it. If it is one of Ford's "Better Ideas" . . . , well, let's just
say it aint the best idea I ever heard!
Will KD3XR ---- the Curmudgeon of Sill Hill
Before flaming, pause. I post to help rv'ers
and annoy morons. Whichever shoe fits, wear it.
Will Sill
ill-considered blather from Mickey:
>Maybe you should guess some more. Both my 83 and my 96 Chevy PU have a
>plastic (or composite) reservoir and an aluminum (or composite) master
>cylinder, and I still haven't found anything in the owner's manuals or
>service manuals for either that recommends or requires periodic changing
>of brake fluid.
Not only that, but I just went out and scanned through my '89 Chilton
Repair Manual and found NOTHING recommending periodic brake fluid
change, other than the flushing & bleeding one would do in the course
of repair work replacing/repairing components.
>I'm siding with the manufacturers. If your manual says change it
>periodically, do so. If it doesn't say change it, do whatever you want.
>But you - or anyone else - have yet to convince me that everybody should
>change their brake fluid every couple of years.
Me too. If this is REALLY a necessary procedure, you'd also have to
change fluid in the clutch system in any old crock with a hydraulic
clutch!
Imagine - all this started because I challenged a daft statement that
brake fuid absorbs 10% water every year!
Todd Kattelman
>In virtually all driving situations, the throttle does not close
>promptly to idle mode when I remove my foot from the accelerator.
>There seems to be a period of several seconds during which it
>maintains a part throttle position before the engine goes to idle
>mode. To avoid fighting throttle with brakes I must anticipate the
>need to slow for several seconds.
>
>My mechanic - an excellent GM-trained guy - tells me that's the way
>they are programmed. He is usually right but not always and I wonder
>why the engine can't be programmed to go directly to idle mode when I
>touch the brakes - even if not just when backing off the accelerator.
>
>Any ideas, facts, or flames?
>
>Will KD3XR
They are designed to come back to an idle slowly to reduce the
emission output. If the throttle closses quickly you have a period of
time which you have excess fuel and not enough air that they are
trying to deal with.
Mickey
> WHen it comes to suffereing, I don't do much! You'd lose some serious
> money with your stupid bet. My "old" GM van is a '99, and like my
> other GM vehciles, it has a sealed translucent reservoir and an owners
> manual that does NOT mention changing brake fluid.
>
of the many posts your van was 11 yrs old. If not, my mistake. The intent
was to suggest your MC may be all metal and not like that found on many
vehicles today. Damn, you sure get your shorts in a knot easily.
Mickey
Will Sill
>Will Sill <wi...@epix.net> wrote in message
>news:c64ugucdiorl7rn8s...@4ax.com...
>> WHen it comes to suffereing, I don't do much! You'd lose some serious
>> money with your stupid bet. My "old" GM van is a '99, and like my
>> other GM vehciles, it has a sealed translucent reservoir and an owners
>> manual that does NOT mention changing brake fluid.
>>
>I do know you like to get the last nasty word in but I thought I read in one
>of the many posts your van was 11 yrs old. If not, my mistake. The intent
>was to suggest your MC may be all metal and not like that found on many
>vehicles today. Damn, you sure get your shorts in a knot easily.
And you, sir, have a remarkably well-developed patina of arrogance,
not to mention poor reading comprehension. I made reference to an
11-year-old pickup truck - which also has a sealed reservoir - same as
most other vehicles of recent vintage.
I notice you ignored virtually all the technical issues in order to
get right down to the personal insults. Congratulations for not
pretending you know ANY of the answers to questions raised.
Thanx for that much.
This lecture brought to you free by Will Sill KD3XR, who hopes you
are not offended by anything you read, inferred, assumed, presumed
or otherwise guessed I might have possibly meant as demeaning -
unless of course you are personally a humorless nitwit who WANTS
to be insulted. In which case be my guest.
Will Sill
about our GMC not going to idle promptly:
>. . . . . When I go to the mountains,
>I disconnect the Throttle Position Sensor (TPS). This gives me immediate
>engine braking when I let off the throttle. It also gives me a slightly
>rough idle, but I can live with that in exchange for engine braking
>while in the mountains.
Thanx.
How do you do that? (Stuff that is possible in a pickup engine bay
requires a contortionist in a van). In yer opinion does it make sense
to put a switch in the appropriate wire?
Will KD3XR
Will Sill
these words after I wrote:
>> . . . . . I wonder
>>why the engine can't be programmed to go directly to idle mode when I
>>touch the brakes - even if not just when backing off the accelerator.
Says he.
>They are designed to come back to an idle slowly to reduce the
>emission output. If the throttle closses quickly you have a period of
>time which you have excess fuel and not enough air that they are
>trying to deal with.
So I am told, but I would MUCH rather waste a few microliters of fuel
that way than waste even more fighting the brakes. Thanx for the
confirmation of the intent, but I was hoping for a fix.
Will KD3XR
Todd Kattelman
>So I am told, but I would MUCH rather waste a few microliters of fuel
>that way than waste even more fighting the brakes. Thanx for the
>confirmation of the intent, but I was hoping for a fix.
>
>Will KD3XR
>
The only fix I know is to let the auto manufacturers make cars that
work the way they should and keep the congress critters and enviro
natzi's out of it.
Neon John
>Will Sill wrote:
>My 96 does the same thing. Always has. It appears to be designed to do
>that, and it annoys the hell out of me, too. When I go to the mountains,
>I disconnect the Throttle Position Sensor (TPS). This gives me immediate
>engine braking when I let off the throttle. It also gives me a slightly
>rough idle, but I can live with that in exchange for engine braking
>while in the mountains.
If you pull the Idle Air Control solenoid lead instead, you won't have any of
those problems, you won't lose acceleration enrichment and you won't come
nearly as likely of setting a code. If you carry a second solenoid (junkyard
for pennies) and plug it in to the connector, then the computer will remain
more or less happy. At least until it runs the part of the OBD-II sequence
where it tests the IAC and sees it's not responding.
Your ECU has probably been hacked (I'd know from the last for digits of the
part number) and if so, that behavior can be modified.
John
---
John De Armond
johngdDO...@bellsouth.net
http://personal.bellsouth.net/~johngd
Cleveland, Occupied TN
Big....@hotmail.com
modern fuel system works and why.
1. Use your brakes as needed to be safe no matter the rate your engine
goes to full idle. If this means drivng 'further down the road', than
the hood ornament, get your view (and mind) out there.
At high speed you have to look further down the road to drive safely.
At low speed you can 'tail gate' and be 'safe'
When I was flying at Mach 2, I had to look a way out in front to be
safe. I the highways I now drive aware of things several hundred yards
(minimum) down the road.
2. Check your brakes at more frequent intervals and replace the
pads/shoes when they show wear to the replacement point due to more
use than in the 'old' days.
Safe on the highways to all.
Big John
bill horne
It's one of the things on the throttle body with wires going to it. The
other is the IAC valve. Although Neon is usually right about technical
stuff, removing the wires to the IAC on my 96 did not affect the delay,
but the TPS did.
I also thought about putting a switch on mine, but didn't. I had
concerns about switching the thing on and off causing a voltage surge to
the computer when it didn't want a surge. Those concerns are probably
unwarranted - particularly since the voltage is lowest at idle (closed
throttle) position - but I wasn't willing to try it. If I was sure that
I could remember to switch the engine off before flipping the switch, I
might do it anyway.
On mine, the wires to the TPS are gray, black, and dark blue. The IAC,
which is right next to it, has some green wires.
And BTW, it doesn't seem to be an air/fuel thing on mine - the TPS feeds
the computer, and the computer tells the transmission to do something.
For example, if I let off the throttle and shift from OD to third, I get
immediate engine braking. If I touch the throttle again, it's about 4-5
seconds before I get engine braking again.
Another example. When I'm going down mountains, and shift to second, I
get immediate engine braking, but if I touch the throttle, the damned
delay comes in again.
With the TPS disconnected, I get immediate engine braking when I let off
the throttle in 1st, 2nd, or 3rd. But as I said, with the TPS
disconnected, it runs a little raggedy.
bill horne
The (Gasp!) theory was - by the dealership - that the engine braking
delay when the throttle was closed was to smooth out the deceleration.
They have a small point, because when I neutralize the delay, it has
some of the jerkiness you get with a standard transmission when you open
and close the throttle - particularly when in 1st or 2nd.
bill horne
>
> I'm supprised with Will's 'background' he didn't know the way the
> modern fuel system works and why.
>
> 1. Use your brakes as needed to be safe no matter the rate your engine
> goes to full idle. If this means drivng 'further down the road', than
> the hood ornament, get your view (and mind) out there.
>
> At high speed you have to look further down the road to drive safely.
> At low speed you can 'tail gate' and be 'safe'
> When I was flying at Mach 2, I had to look a way out in front to be
> safe. I the highways I now drive aware of things several hundred yards
> (minimum) down the road.
>
> 2. Check your brakes at more frequent intervals and replace the
> pads/shoes when they show wear to the replacement point due to more
> use than in the 'old' days.
>
> Safe on the highways to all.
>
> Big John
Nevertheless, this engine braking delay is a pain in the ass -
particularly when in the mountains in 1st or 2nd gear. I've gotten used
to it in normal town and hiway driving, but when I let off the gas in
the mountains, I want engine braking, and I want it NOW.
Lon VanOstran
> The only fix I know is to let the auto manufacturers make cars that
> work the way they should and keep the congress critters and enviro
> natzi's out of it.
Good luck! The sheeple like having bureaucrats tell the engineers how to
build cars.
Lon
Chris Bryant
<<..>>
>And you, sir, have a remarkably well-developed patina of arrogance,
>not to mention poor reading comprehension.
<<..>>
>I notice you ignored virtually all the technical issues in order to
>get right down to the personal insults. Congratulations for not
>pretending you know ANY of the answers to questions raised.
Yeah, Mickey- these traits are Will's department.
Sandy A. Nicolaysen
>
>Nevertheless, this engine braking delay is a pain in the ass -
>particularly when in the mountains in 1st or 2nd gear. I've gotten used
>to it in normal town and hiway driving, but when I let off the gas in
>the mountains, I want engine braking, and I want it NOW.
Bill: My solution was to simply hack the code. I left the delay in
for driving in overdrive, but eliminated the delay for any other gear.
The logic behind this is that I normally tow in drive (1:1) and not
overdrive. When towing, my '98 truck acts like a good old-fashioned
carbureted engine. If I happen to WANT to free wheel, I shift to
overdrive and coast down the hill.
But you and I share the same gripe. I wonder what it would take to
convince the manufacturer to make the same modification?
Regards, - Sandy
Big....@hotmail.com
Don't know. I just looked at the owners manuel and also the shop
manuel and didn't find any time/milage to change the brake fluid????
Shortly after I bought the car my wife had a complete brake failure
and minor accident. There was lots of correspondence with Olds
concerning this. It is possible that in the data they sent me it was
included there???? Will continue to look more in detail as may have
missed???
I did find in my looking today that they recommend the brake fluid NOT
be changed and flushed in 'older' cars due to it moving the junk from
the master cylinder to the wheel cylinders where it could cause
binding and scoring...............
As I recall the reson for the change of fluid was due to the ABS
having very close tolerances and junk in the fluid would/could cause
ABS failure..
Bottom line. I agree that fluid that is discolored should be changed.
My experience with fluid with a dark color showed that there was
solids in the fluid ( a no no)..
And you'all have a nice day.
Big John
Big....@hotmail.com
What I said was, if you want ot slow down put on the brakes. That's
what they are there for.
If/when the engine (gas only) slows down to a slow idle and gives some
braking that is a bonus.
I can remember when I started driving a model'T" and had no use for
the buggy whip. I learned and moved on into the 20th Century. It's
time now to move into the 21th century. :-)
If you are in the mountains and start down do you shift down at the
top or way down the hill when you are going like a bat out of hell? If
you shift on top the engine has slowed down before you even start
down the hill. I really can't see it as a big problem.
Big John
bill horne
> >> My 91 Olds '98 says to change the brake fluid also. (One of the big
> >> three).
> >>
> >> Big John
> >
> >When are you supposed to change it?
> >
> >--
> >bill
Ok. First you say:
"My 91 Olds '98 says to change the brake fluid also. (One of the big
three)."
Then I say:
"When are you supposed to change it?"
Now you say:
"Don't know. I just looked at the owners manuel and also the shop manuel
and didn't find any time/milage to change the brake fluid????"
Uh huh. I see.
bill horne
>
> Bill
>
> What I said was, if you want ot slow down put on the brakes. That's
> what they are there for.
>
> If/when the engine (gas only) slows down to a slow idle and gives some
> braking that is a bonus.
>
> I can remember when I started driving a model'T" and had no use for
> the buggy whip. I learned and moved on into the 20th Century. It's
> time now to move into the 21th century. :-)
>
> If you are in the mountains and start down do you shift down at the
> top or way down the hill when you are going like a bat out of hell? If
> you shift on top the engine has slowed down before you even start
> down the hill. I really can't see it as a big problem.
>
> Big John
If you drove my truck in my mountains, you'd see the problem. I'll try
to explain it to you.
I go to the mountains. I get on steep, twisty, FS dirt roads. I get in
first gear so I don't have have to ride my brakes. Sometimes the road
levels off, and I have to give it a little gas to keep moving - because
when my engine manages to brake in first gear, it brakes damned goodful.
Then it gets steep again, and I let off the gas, and my damned engine
braking is gone, and I have to ride the brakes until the damned timer
times out. and by then, it's time to give it a little gas again - and
reset the damned timer again. Fooey.
Now picture the same thing on GA 60 - which is a paved, but twisty and
steep, road. I want to drive this road in second gear to minimize brake
use, but I have the same damned problem - only at a higher speed.
The bottom line is that the damned delay requires me to spend much more
time on the brakes than I would have to if the damned engine braking
were immediate - like ALL of my other vehicles have been. I know this,
because when I go to the mountains, I stop at the first scenic view,
view the scene, and then pop the hood and disconnect the damned TPS.
Then I drive the mountains as they should be driven - mostly engine
braking.
It doesn't have squat to do with moving into the 21st century - unless
progress means using my brakes more than I should have to.
Marc
injection system is you run the risk of sending excess unburnt fuel into the
catalytic (? spelling ) converters . I am sure they are at the extreme maxium
wanted temperature when towing, last thing they need is any unburnt fuel
hitting them & generating still more heat. If they overheat - then the
internals can have a melt-down & thus plugging up & reducing your performance.
I would also say you wouldn't be a happy camper if you ever got stopped at a
roadside smog inpection ( I know they are few & far between).
Is this problem uique to GM ? Is it a bad batch of computers ? - I never had
that type of problem in fords ( 87 F-150 302 FI, 94 E-250 351 FI, or 97 F150 FI
)
bill horne
> Is this problem uique to GM ?
Beats me. And GM may not consider it a problem. When I get out of my
truck, the interior light stays on for about 20 seconds. They don't
consider that a problem, either.
> Is it a bad batch of computers ?
Beats me.
> - I never had
> that type of problem in fords ( 87 F-150 302 FI, 94 E-250 351 FI, or 97 F150 FI
> )
Count your blessings.
Will Sill
>I'm supprised with Will's 'background' he didn't know the way the
>modern fuel system works and why.
I know less than I'd like, but that is not the issue.
>1. Use your brakes as needed to be safe no matter the rate your engine
>goes to full idle. If this means drivng 'further down the road', than
>the hood ornament, get your view (and mind) out there.
Dear John,
You Just Don't Get It. When I constantly have to use braking BECAUSE
the danged throttle doesn't close when _I_ need it to, that's a defect
from my POV. Sorry you don't agree. BTW I am fairly good at
defensive driving techniques, so can the sarcasm.
>2. Check your brakes at more frequent intervals and replace the
>pads/shoes when they show wear to the replacement point due to more
>use than in the 'old' days.
Not acceptable to me. If you think that's "progress" we'll have to
agree to disagree. Look at Bill Horne's comments about the problem,
and also consider this:
I enter a village with a reduced speed limit as follows:
1) Kick off the CC the moment I see the "reduce speed ahead" sign
2) Grumble under breath because #$%^&*( engine goes to part throttle
3) Ride brakes for a while to get down to desired speed
4) Touch throttle again to maintain new speed, see traffic light ahead
5) Repeat step 2
6) Etc, ad nauseum.
It's not a Huge Problem but it's a serious annoyance in what is
otherwise a very satisfactory rig.
So thanx for nothing.
"Most people are about as happy as they make up their
minds to be." [A. Lincoln]
Will KD3XR
Will Sill
>> >. . . . . When I go to the mountains,
>> >I disconnect the Throttle Position Sensor (TPS). This gives me immediate
>> >engine braking when I let off the throttle. It also gives me a slightly
>> >rough idle, but I can live with that in exchange for engine braking
>> >while in the mountains.
Sez me:
>> Thanx.
>> How do you do that? (Stuff that is possible in a pickup engine bay
>> requires a contortionist in a van). In yer opinion does it make sense
>> to put a switch in the appropriate wire?
Rats & fooey. I was hoping it was something fairly easy to do - on
our rig it sounds like a Big Hassle. But thanks for the confirmation
and the data!
Will KD3XR
Will Sill
HA! Can't imagine what terrorist attack would be necessary to get GM
to fix it! I wonder what it would take to get you to hack the 'puter
on MY rig! I'd be happy if the logic was to eliminate the delay when
the brakes are touched!
Will KD3XR
JanOrme99
-------------------------------------------------------------
This is hilarious!
Will and Bill, I'm sorry but you guys are really misinformed/full of shit/out
to lunch on this one.
Of course you should take issue with any statement that says, "brake fuid
absorbs 10% water every year!" BUT...brake fluid does absorb water and
contaniments over time AND should be changed. Yes, every couple of years.
AND...way less than 10% will put you and your system in potential trouble.
AND....does Chilton or the GM manual tell you to stop and gas up your rig so
you won't run out? Gentlemen, brakes on vehicles are a very touchy subject with
board room attorneys. They don't like to tell the public much of ANYTHING or
give much advice because when they get to court when Brand X brakes failed
before the recommended change date....blah blah blah. It's the world as we live
in it fellas.
AND...forget the saw about "they tell me when to change my oil."
Care of brakes ain't like changing oil!
Run your engine out of oil and your engine may die. Brake failure due to poor
fluid equals a potential dirt nap! As my good friend Chief Track Steward Tom
Georgalos says in a drivers meeting, about going off course for some
agricultural racing, "DIRT..WALL..DEATH!"
This subject would be funny if it wasn't so serious.
A race car is a vehicle that is used under high stress and what could be called
"heavy duty." An RV and/or tow vehicle is a ditto. Not as extreme but still
heavy duty for sure.
I have been around folks that maintain race cars now for a while. Brakes are
like number one on the maintenace list. On a real serious race car, guess what?
The brake fluid gets changed out for every race. For moderate use performance
cars with less severe use like Auto Cross or time trials etc. probably twice
per season and bleed for every event.
In case you are wondering. I use Motul 600 for any of my performance/race
car(s).
Here is some light reading:
http://www.carcarecouncil.org/brak199.htm
http://www.hotrodheaven.com/tech/brakes/brakes8.htm
http://www.babcox.com/editorial/bf/bf30066.htm
http://silverstone.fortunecity.com/ferrari/464/index.htm
http://members.rennlist.com/911pcars/brakefluid.htm
BTW, for heavy duty street use the Ford HD is probably the cheapest real good
quality high temp product. Some weekend racers use it because it's like 1/3 the
cost of the expensive stuff. I suspect that the Ford HD, AP Racing 550 and
Performance friction Z is all the same stuff with different labels.
Jan Eric Orme
"Good judgment comes from
experience, and a lot of that
comes from bad judgment."
-Will Rogers
bill horne
-------------------------------------------------------------
> This is hilarious!
Yeah, it sure is. So is the stuff about Black Pyramids and toilet paper
in mayonaisse jars - for about the same reason.
> Will and Bill, I'm sorry but you guys are really misinformed/full of shit/out
> to lunch on this one.
Ok, maybe I am. Show me in my manuals where it tells me to - or even
suggests that - I should change my brake fluid every two years, and
I'll reconsider my lunch habits.
> Of course you should take issue with any statement that says, "brake fuid
> absorbs 10% water every year!" BUT...brake fluid does absorb water and
> contaniments over time AND should be changed. Yes, every couple of years.
> AND...way less than 10% will put you and your system in potential trouble.
>
> AND....does Chilton or the GM manual tell you to stop and gas up your rig so
> you won't run out?
Nope, but it tells me How to do it, and it doesn't mention periodic
flushing of the gas tank.
> Gentlemen, brakes on vehicles are a very touchy subject with
> board room attorneys. They don't like to tell the public much of ANYTHING or
> give much advice because when they get to court when Brand X brakes failed
> before the recommended change date....blah blah blah.
I guess that's why they spend 4 pages telling me about brakes - two and
a half of them about brake fluid. They tell me how to check brake fluid.
They tell me the wrong kind of fluid can cause a crash. But not one word
or hint about changing it periodically.
> It's the world as we live
> in it fellas.
And I'm still living in it - after 45 years of driving, and never
periodically changing my brake fluid - except once in the Mazda. I'm
just lucky, I guess.
> Run your engine out of oil and your engine may die. Brake failure due to poor
> fluid equals a potential dirt nap! As my good friend Chief Track Steward Tom
> Georgalos says in a drivers meeting, about going off course for some
> agricultural racing, "DIRT..WALL..DEATH!"
Snipped all the stuff about race cars, because my truck ain't one. If it
were, I'd have to change the tires every couple of hundred miles, and
the oil every time I took a little trip. Many of them tear down the
engine after every trip. I don't do that, either. Race car drivers have
to do a lot of things to their cars that I don't have to do to my little
teal green trucklet.
> Jan Eric Orme
bill horne
> Rats & fooey. I was hoping it was something fairly easy to do - on
> our rig it sounds like a Big Hassle. But thanks for the confirmation
> and the data!
>
> Will KD3XR
If you can see and reach the throttle body, it is easy - the connector
just pops off. Or you could just do the job once, and put a switch on
it, and take the probably very small chance of smoking part of the
computer if you use the switch with the engine running. Maybe somebody
who actually knows about car computers could tell us what the likelihood
is, and why.
Will Sill
>Will and Bill, I'm sorry but you guys are really misinformed/full of shit/out
>to lunch on this one.
>
>Of course you should take issue with any statement that says, "brake fuid
>absorbs 10% water every year!" BUT...brake fluid does absorb water and
>contaniments over time AND should be changed. Yes, every couple of years.
>AND...way less than 10% will put you and your system in potential trouble.
I respect your opinions but don't plan to change the brake fluid in my
light GM vehicles unless/until it seems appropriate to me. Not that
I'm against preventive measures - in fact, the contrary is true.
Perhaps I'm mistaken, but unless the manufacturer - who after all is
definitely in the CYA mode! - suggests it in the manuals, I am more
concerned about the various problems arising from flushing/bleeding
incorrectly.
But please don't get me wrong on this - I most certainly DO favor
changing fluid when doing any service work other than routine pad/shoe
replacement, whenever there's a leak anywhere, and of course if yer
manual suggests it. I'll go farther and say that extreme service
applications (racing qualifies!) justify periodic changing as well.
Will KD3XR
Will Sill
throttle position sensor (recent GM products) and I was kinda
intimidated and wrote:
>> Rats & fooey. I was hoping it was something fairly easy to do - on
>> our rig it sounds like a Big Hassle. But thanks for the confirmation
>> and the data!
Sez Bill:
>If you can see and reach the throttle body, it is easy - the connector
>just pops off.
Next time you cannot resist the urge to stop in and palaver with the
Eager, Competent Staff at yer local GM dealer, pop what passes for a
hood on a full-sized van - any one will do. After you see what's
visible under that hood, you'll understand why I don't know what's
buried in there! And BTW I don't think the '99's use a throttle body
setup for EFI any more.
Thank Heaven the thing is reliable, because it just ain't hardly
possible to work on stuff in there.
>Or you could just do the job once, and put a switch on
>it, and take the probably very small chance of smoking part of the
>computer if you use the switch with the engine running. Maybe somebody
>who actually knows about car computers could tell us what the likelihood
>is, and why.
I sure would like to hear some credible source on exactly that type of
thing. No doubt a few people think the factory setup is just ducky,
but then some people watch Oprah and enjoy doing so!
Will KD3XR
bill horne
> Next time you cannot resist the urge to stop in and palaver with the
> Eager, Competent Staff at yer local GM dealer, pop what passes for a
> hood on a full-sized van - any one will do. After you see what's
> visible under that hood, you'll understand why I don't know what's
> buried in there! And BTW I don't think the '99's use a throttle body
> setup for EFI any more.
Well, if you ain't got a throttle body, you may not have a throttle. And
if you ain't got a throttle, you probably ain't got a Throttle Position
Sensor. And if you ain't got a TPS, disregard everything I've said this
week.
Will Sill
>Will Sill wrote:
>
>> Next time you cannot resist the urge to stop in and palaver with the
>> Eager, Competent Staff at yer local GM dealer, pop what passes for a
>> hood on a full-sized van - any one will do. After you see what's
>> visible under that hood, you'll understand why I don't know what's
>> buried in there! And BTW I don't think the '99's use a throttle body
>> setup for EFI any more.
>
>Well, if you ain't got a throttle body, you may not have a throttle. And
>if you ain't got a throttle, you probably ain't got a Throttle Position
>Sensor. And if you ain't got a TPS, disregard everything I've said this
>week.
Everything? Egad!
Will KD3XR
Sandy A. Nicolaysen
I don't want to get into a flame war, but I have to put my 2¢ in here
before someone does something really stupid.
If you have a GM Vortec engine, disabling the throttle position sensor
will give you more grief than benefit. My TPS went bad two years ago
and the symptoms were the truck didn't want to upshift. A hard
"failure", i.e. disconnecting, the connection to the TPS will cause
the ECU to go into limp home mode. You'll suffer poorer mileage and
no timing advance, meaning less horsepower.
I've been hacking these computers since 1981 when I changed the code
in a '81 Monte Carlo. GM has made mistakes in the past, like when I
pointed out to them that killing timing advance when coolant temp
reaches 170 degrees doesn't work well when you install a 195 degree
thermostat at the factory.
As I've stated in another thread, Bill Horne has a legitimate gripe
about the lack of engine braking caused by delayed throttle closing.
As far as emissions issues are concerned, we've managed to make it
from 1974 to 1980 without computerized controls and mandated catalytic
converters. IMO early throttle closure will not cook the cat.
Maybe if Bill would post what year/make truck he has I could give some
more insight to this.
Regards, - Sandy
Lon VanOstran
It's OK, Will. At our age, we forgot most of it already anyway. <G>
Lon
Will Sill
>I don't want to get into a flame war, but I have to put my 2¢ in here
>before someone does something really stupid.
HA! It is MUCH too late for that!
>If you have a GM Vortec engine, disabling the throttle position sensor
>will give you more grief than benefit.
SInce mine is the Vortec 5.7L, I was kinda afraid of that but still
don't know what (if anything) is practical to do about the problem.
>I've been hacking these computers since 1981 when I changed the code
>in a '81 Monte Carlo. GM has made mistakes in the past, like when I
>pointed out to them that killing timing advance when coolant temp
>reaches 170 degrees doesn't work well when you install a 195 degree
>thermostat at the factory.
GM (and Ford and CD etc) have all made some blunders, IMO this idle
delay crap is one of them, but rather than just grouse about it I
hoped I might get some tips on how to circumvent it. So far, all
I've got is suggestions that I am stupid (not a new report!), that I
am not the only one who finds the feature annoying, and that at least
one person did somthing that helped HIM but apparently won't help me.
>As I've stated in another thread, Bill Horne has a legitimate gripe
>about the lack of engine braking caused by delayed throttle closing.
>As far as emissions issues are concerned, we've managed to make it
>from 1974 to 1980 without computerized controls and mandated catalytic
>converters. IMO early throttle closure will not cook the cat.
I wondered about that. Our GMC has TWO three inch cats - sure seems
like overkill for a 350 ci engine!
>Maybe if Bill would post what year/make truck he has I could give some
>more insight to this.
Bill has mentioned what he has - mine is a '99 GMC 3500. Any
insights for that?
DISCLAIMER:
My advice is useless. I have no university degrees and
have never towed a 34' TT with an Intrepid. Though I have
done some near-Darwin-award dumb things in the past, and
often still make errors, I currently own NO Banks headers,
fuel magnets, deer whistles, "Smart" solenoids or louvered
tailgates. I've never deliberately allowed a holding tank to
freeze solid, and have no financial interest in whether you
join RVCG, wear clothes, overinflate your tires or hate
Firestone. If you take my advice, I guarantee absolutely NOTHING.
Got that?
Will Sill KD3XR
bill horne
> As I've stated in another thread, Bill Horne has a legitimate gripe
> about the lack of engine braking caused by delayed throttle closing.
> As far as emissions issues are concerned, we've managed to make it
> from 1974 to 1980 without computerized controls and mandated catalytic
> converters. IMO early throttle closure will not cook the cat.
>
> Maybe if Bill would post what year/make truck he has I could give some
> more insight to this.
>
> Regards, - Sandy
96 Chevy PU, 5.7L Vortec. I could be wrong, but I don't think it has
anything to do with a delayed throttle closing. I think the throttle is
closing when I let off the gas. The TPS tells the computer something,
and about 5 seconds later, the computer tells the transmission
something. I think this for two reasons:
1. I don't see any device on the throttle body or accelerator cabling
that could hold the throttle off idle.
2. If I simultaneously let off the gas and downshift, engine braking is
immediate. More on this: (Assume I'm now in second gear)
If I touch the gas pedal, engine braking is gone for about 5 seconds.
However, if I shift to third and back to second, engine braking occurs
as soon as I shift back to second, even if the 5 seconds has not
elapsed.
A similar thing happens in third. If I let off the gas and shift from OD
to third, engine braking is immediate. If I touch the gas, the ole 5-sec
delay once again appears.
Same in first, or going from second to first.
So, other than disconnecting the TPS, what else can I do? I know nothing
about car computer hacking.
Jon Porter
"Will Sill" <wi...@epix.net> wrote in message
news:7hp1hu8flmmf1khhc...@4ax.com...
>
> Next time you cannot resist the urge to stop in and palaver with the
> Eager, Competent Staff at yer local GM dealer, pop what passes for a
> hood on a full-sized van - any one will do. After you see what's
> visible under that hood, you'll understand why I don't know what's
> buried in there! And BTW I don't think the '99's use a throttle body
> setup for EFI any more.
>
Step one for working on the engine in a Ford or Chevy van - remove the air
box.
Step two - remove anything else as it gets in the way of what you're doing.
Neon John
>"Sandy A. Nicolaysen" wrote:
>
>> As I've stated in another thread, Bill Horne has a legitimate gripe
>> about the lack of engine braking caused by delayed throttle closing.
>> As far as emissions issues are concerned, we've managed to make it
>> from 1974 to 1980 without computerized controls and mandated catalytic
>> converters. IMO early throttle closure will not cook the cat.
>>
>> Maybe if Bill would post what year/make truck he has I could give some
>> more insight to this.
>>
>> Regards, - Sandy
>
>96 Chevy PU, 5.7L Vortec. I could be wrong, but I don't think it has
>anything to do with a delayed throttle closing. I think the throttle is
>closing when I let off the gas. The TPS tells the computer something,
>and about 5 seconds later, the computer tells the transmission
>something. I think this for two reasons:
>
>1. I don't see any device on the throttle body or accelerator cabling
>that could hold the throttle off idle.
That is correct. Idle control is done by a totally separate device called the
Idle Air Control valve. This is a stepper motor-operated valve that bypasses
air around the throttle plate. The ECU uses this motor to control the idle
speed, to improve mileage and several other things including emissions and NVH
reductions.
Under the theory that a picture is worth a thousand words, here is a photo of
the throttle body from a Vortec engine:
http://personal.cha.bellsouth.net/cha/j/o/johngd/files/car/Vortec%20Throttle%20Body.jpg
This is one of two such throttle bodies that I'm using on a twin turbo LS1
engine I'm currently working on. The IAC motor is identified in the photo.
There is a weatherpack-style connector containing 4 pins that plugs into that
motor. If you disconnect this connector, you disable the IAC function.
You'll also eventually cause the computer to set a code. If you get a spare
IAC motor from the junkyard or whatever and plug IT into the connector instead
of leaving it dangling, you will make the ECU much happier. It still will
evetually set a code when the OBD-II IAC test fails but that takes time.
If you want to switch this unit off, you'll need a DPST switch. There are two
pairs of wires; you'll need to break one of each pair. The stepper motor
remains in the last place it was driven so it is a good idea to flip the
switch at idle. That is, if you want a normal idle.
Taking out the IAC is MUCH more satisfactory than the TPS. The TPS is used
for a wide variety of functions and is vital for smooth engine operation.
>
>2. If I simultaneously let off the gas and downshift, engine braking is
>immediate. More on this: (Assume I'm now in second gear)
>If I touch the gas pedal, engine braking is gone for about 5 seconds.
>However, if I shift to third and back to second, engine braking occurs
>as soon as I shift back to second, even if the 5 seconds has not
>elapsed.
>
>A similar thing happens in third. If I let off the gas and shift from OD
>to third, engine braking is immediate. If I touch the gas, the ole 5-sec
>delay once again appears.
>
>Same in first, or going from second to first.
All this is normal.
John
---
John De Armond
johngdDO...@bellsouth.net
http://personal.bellsouth.net/~johngd
Cleveland, Occupied TN
bill horne
Ok, but when I disconnected the IAC (with engine off), and then ran down
the road, why didn't it eliminate the delay?
HHamp5246
fluid......
http://www.google.com/search?hl=en&q=%22change+brake+fluid%22&btnG=Google+
Search
Hunter