Brake Fluid Revisited
Cass
I sure wish you could find that study.
Cass
"bill horne" <red...@rye.net> wrote in message
news:3EAC7C59...@rye.net...
> Chris Bryant wrote:
>
> Snipped everything that we've beat to death before. If there's some
> particular thing you want me to respond to, say so, and I'll try.
>
> > Bad, bad advise. My recommendation- which is what it has
> > always been, and anyone with 1/2 a brain could see is reasonable- is
> > that *If you have a vehicle which you are operating at or near its
> > GVW, you should regularly have the brake fluid tested, and changed as
> > needed. It doesn't take much moisture to greatly reduce the boiling
> > point of BF, and only a fool would recommend otherwise.
> >
> > Of course, I would never recommend deliberatively disabling a
> > safety device, either.
> >
> > --
> > Chris Bryant
> > Bryant RV Services- http://www.bryantrv.com
>
> My recommendations are what they've always been:
>
> 1. Do what the owner's manual for your particular vehicle recommends.
> 2. Modern brake systems are sealed. Unless you open them.
>
> And here's a short summary of what I did last year.
>
> Poured some new BF into a powder scale pan and weighed it.
>
> Weighed it pretty much randomly over the next 15 days. 33 times.
>
> It started at 89.9 grains. On the 9th day, it reached 106.5 grains.
> Between the start and the 9th day, it generally increased, but there
> were numerous instances of decreases. On the 15th day, it had decreased
> to 90.4 - only a half a grain of water from the new BF.
>
> But as to BF sucking moisture through the hoses, I doubt it. But if it
> does, it's only logical to me that the moisture will also go the other
> way. Why would brake hose engineers make hose that only inhales water,
> but doesn't exhale it? Particularly since inhaling is bad, and exhaling
> is good.
>
> And my opinion remains that if your manual does not recommend periodic
> changing of BF, you are more likely to introduce water and other
> contaminants by peering into the MC, by opening it to 'check' it, or by
> changing it. And speaking of fools - and you did - what are the odds of
> getting a fool to change your brake fluid? The last time that came up,
> some fool said to find a reliable BF changer. Yeah, well, that's easier
> said than done.
>
> If you insist, I'll post - again - all the sources that led me to that
> opinion. If I can find them.
>
> Decades ago (around 1970), some organization - gummit or otherwise (I
> forget which) - did a study in California. The bottom line was that with
> the incompetence and/or the crookedness, you had a 25% chance of getting
> the job done right.
>
> --
> bill
> Theory don't mean squat if it don't work.
ray
>>>always been, and anyone with 1/2 a brain could see is reasonable- is
>>>that *If you have a vehicle which you are operating at or near its
>>>GVW, you should regularly have the brake fluid tested, and changed as
>>>needed. It doesn't take much moisture to greatly reduce the boiling
>>>point of BF, and only a fool would recommend otherwise.
IIRC It's somewhere around 2% water = 50% decrease in temp for boiling.
>>1. Do what the owner's manual for your particular vehicle recommends.
>>2. Modern brake systems are sealed. Unless you open them.
They are not THAT sealed. The master cylinder lid isn't exactly
airtight, especially the older the car is the more likely it's not
quite airtight.
I've started to siphon a 1/2 a master cylinder out at every oil change
and replace with fresh fluid. Even last year on a one year old car the
stuff that was in there was already starting to discolor. (I also
bled the brakes on it as well to get as much new fluid in there as
possible.)
Ray
Mike F
brake line rust out. I've never changed brake fluid, keep my vehicles for
15+ years, and have never experienced a brake system rust problem. What
gives?
Mike
Will Sill
words:
>I've started to siphon a 1/2 a master cylinder out at every oil change
>and replace with fresh fluid. Even last year on a one year old car the
>stuff that was in there was already starting to discolor. (I also
>bled the brakes on it as well to get as much new fluid in there as
>possible.)
It's your vehicle - do what you like. Personally I would not think of
opening up a sealed system at every oil change. The risk of
contamination AND getting moisture in the system is MUCH greater than
if you just left it alone.
Will Sill
Will Sill
Mike, there are books that will tell you almost anything. Go by the
OWNERS MANUAL (or service manual if you have one). Very few even
mention periodic BF changes - for the obvious reason that it isn't
necessary on most vehicles.
Will Sill
Bruce Chang
"Will Sill" <wi...@epix.net> wrote in message
news:654ravkdj1vaoosbl...@4ax.com...
The risk of contamination and getting moisture in the system? What? Is
someone shooting water with grit in it at you while you're opening the brake
fluid cover? Oh.. you mean the negligible risk that you might get a grain
of sand or dust? If he's siphoning off the fluid he's reducing the amount
of brake fluid that has already absorbed moisture and fluid that has
suspended contaminants in it. Sure you could just leave it alone and when
your brake lines rust through or you have a spongy pedal, don't tell us we
didn't warn you. If it were a truly sealed system, brake fluid would never
get any additional moisture in it and we wouldn't be having this discussion.
-Bruce
C. E. White
ray wrote:
> >>> Bad, bad advise. My recommendation- which is what it has
> >>>always been, and anyone with 1/2 a brain could see is reasonable- is
> >>>that *If you have a vehicle which you are operating at or near its
> >>>GVW, you should regularly have the brake fluid tested, and changed as
> >>>needed. It doesn't take much moisture to greatly reduce the boiling
> >>>point of BF, and only a fool would recommend otherwise.
>
> IIRC It's somewhere around 2% water = 50% decrease in temp for boiling.
>
I don't think you phrased this correctly. For DOT 3 Brake Fluid, the
uncontaminated boiling point must be at least 401 degrees F. With 2%
moisture will drop it to around 320 degrees F. Temperature scales use an
arbitrary zero point, so saying it can reduce the boiling point by 50% is
very uninformative. Using the above information for the Fahrenheit scale, 2%
moisture reduced the boiling point by 20%. If you used the same information,
but converted it to the Celsius Scale, then the reduction would be 22%. If
you used the Rankine scale, then the percent change would be less than 10%.
Regards,
Ed White
Will Sill
>The risk of contamination and getting moisture in the system? What? Is
>someone shooting water with grit in it at you while you're opening the brake
>fluid cover? Oh.. you mean the negligible risk that you might get a grain
>of sand or dust? If he's siphoning off the fluid he's reducing the amount
>of brake fluid that has already absorbed moisture and fluid that has
>suspended contaminants in it. Sure you could just leave it alone and when
>your brake lines rust through or you have a spongy pedal, don't tell us we
>didn't warn you. If it were a truly sealed system, brake fluid would never
>get any additional moisture in it and we wouldn't be having this discussion.
Obviously someone has crossposted the tail end of a long discussion,
leaving you with only a few scraps of information.
I started this current flame war by merely posting the results of an
11-month test to rec.outdoors.rv-travel. FYI - that post follows:
==============
Almost a year ago there was considerable (ahem) discussion in this
venue about brake fluid, wherein some parties alleged emphatically
that brake fluid:
- when exposed to air absorbs water up to 10%/year
- won't mix with water, so water settles to the bottom
- will rust steel once water is allowed to enter
- has such a frantic appetite for water that it sucks it through seals
and brake hoses
In the intervening 11 months my experiment has established beyond
reasonable doubt that ALL of these beliefs are erroneous (putting it
mildly). For those new to the topic, I poured a mixture of BF & water
into a mason jar, and added two naked steel 1/4-20 nuts. One of the
latter is suspended where the surface of the mixture was at the start
of the experiment, the other lays in the bottom. Results include:
1) enough water had evaporated to _reduce_ the volume to almost
exactly _60%_ of the original amount, thereby proving conclusively
that BF doesn't continuously absorb water.
2) there has never at any time been any visible evidence of separation
3) there has yet to be the first visible trace of rust on either nut
4) since an open container in a damp basement failed to collect
additional water, it seems fair to conclude that Chris Bryant was dead
wrong with his claim that BF will suck moisture through brake hoses &
seals.
================
The meaning of all this for the rv'ers? You are more likely to cause
trouble than to stave it off by changing BF unnecessarily. Keep the
system full and don't sweat it. If your owners manual says change it
from time to time, do so. If not, have a beer instead.
Will ---- the Curmudgeon of Sill Hill
Before flaming, pause. I post to help rv'ers and annoy the snot
out of morons, idjits, fools and bozos - - and to irk their ilk.
Often, I do both at once.
============
Since that time, the usual flurry of objections and accusations have
appeared. Feel free to add more verbiage if you think it is helpful.
Will Sill
Mike Romain
Rotted brake lines and crud in the fluid are a major headache around
here on old vehicles. I am in the rust belt where 100% humidity can
happen on sunny days...
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Cass
The mistake that you make here ( I do the same) is that you are thinking
that you are dealing with rational, intelligent and knowledgeable folks who
sincerely want to learn something.
Many have not even been able to read your results correctly much less,
understand what they are reading.
Others can't keep the attibutes correct as to who said what to whom. Some
just want to argue. One RV hatcheman (Bryant) runs away without realizing
what is being said and calls you a troll and on and on and on.
There are a few here that are not listed above but a very few, indeed.
Cass
"Will Sill" <wi...@epix.net> wrote in message
news:m96rav4okedfjv7ta...@4ax.com...
Mike F
system. The subsequent total seal failure led to total brake failure 300
miles from home, leading to a 300-mile drive (no parts available locally)
with only the parking brake to stop my 5,000# SUV. THAT was followed by two
years of trying to find the right replacement parts, giving up, having three
old-fashioned REAL brake experts try many times to restore braking power,
giving up on OEM replacement parts and adding double stage vacuum pumps and
other aftermarket stuff, and finally giving up and spending the next five
years with substandard brakes on an off-road vehicle used in terrain lizards
would pee their pants in (example: measured slopes exceeding 45 DEGREES
[100% grades]).
That's what I get for buying an exotic SUV and opening the brake system for
no good reason. The "exotic SUV"? A 1972 Chevy Blazer. Every dealer we
contacted the next two years swore it didn't even HAVE the proportioning
valve that came from Detroit bolted under the master cylinder.
I don't open brake systems any more until they NEED fluid, and then I do it
fast so they don't have time to absorb much moisture.
Mike
"Will Sill" <wi...@epix.net> wrote in message
news:654ravkdj1vaoosbl...@4ax.com...
Brent P
> 3) there has yet to be the first visible trace of rust on either nut
This matches my experience. I've never had a brake line fail from
rust coming from the inside. Every hard line I've replaced has been
the result of rust from the outside, from the road salt and water
mix each winter. In fact, a few hadn't failed until I had to replace
the hose they were attached to, but were too weakened and the fitting
rusted to the line so they broke when I went to remove the hose. The
inside of the line, when broken or cut open always appeared clean as
new.
Steve
> It's your vehicle - do what you like. Personally I would not think of
> opening up a sealed system at every oil change. The risk of
> contamination AND getting moisture in the system is MUCH greater than
> if you just left it alone.
>
> Will Sill
Absurd. Brake fluid level should be checked EVERY oil change (more
often, really). Checking the level requires opening the reservoir cap
(trying to guess the level in so-called see-through master cylinder
reservoirs is not reliable). Modern brake systems are no more "sealed"
than they were in 1960. The cap on the master cylinder keeps out splash,
dust, and dirt, but it is not air-tight and moisture still can get in.
Brent P
> Absurd. Brake fluid level should be checked EVERY oil change (more
> often, really). Checking the level requires opening the reservoir cap
> (trying to guess the level in so-called see-through master cylinder
> reservoirs is not reliable).
Considering the floating 'plug' in them looking in to see if it is
at the full mark (often below the floating plug) is not accurate
either.
Ray
And three years from now when you need to get those bleeder screws
off ... it's torch and visegrips time.
The wife's Beretta's rear wheel cylinders spring a leak about every
three years. Crappy design, but not worth re-engineering the whole
system.
I've also boiled the brake fluid in my Trans Am - hotlaps on the
local road course - so changing it is a good idea.
Ray
Ray
Did you test boiling points before mixing and after?
How about the boiling point of the fluid in your RV once a year?
How much does it cost to flush your brake system?
Ray
Ray
That's where the IIRC came from - I couldn't recall the #'s, but
all I've ever needed to know was Brake Fluid + Water = lower boiling
point. Most of the cars I've owned have been old beaters so the brake
system is usually filled full of brown/black sludge when I got them...
and $5 in fresh brake fluid was a good idea. Good way to find rotted
brake lines BEFORE they failed...
Ray
Ray
>
> Absurd. Brake fluid level should be checked EVERY oil change (more
> often, really). Checking the level requires opening the reservoir cap
> (trying to guess the level in so-called see-through master cylinder
> reservoirs is not reliable). Modern brake systems are no more "sealed"
> than they were in 1960. The cap on the master cylinder keeps out splash,
> dust, and dirt, but it is not air-tight and moisture still can get in.
There is a seal - that flimsy rubber gasket thing. I think they are
mostly airtight, but you can't convince me a plastic clip-on top
is 100% airtight. I think the old cast iron MCs were better for
seals...
You know what I've concluded? People are cheap. They won't change
their oil any sooner than they HAVE to, and it's the same with any
fluids on their car. Preventative maintenance is foreign to them.
In the last couple of years I've started doing more PM work on my
"fleet" and when poking around changing fluids and filters more often
than I've had to, I've found stuff that's starting to wear out and
can keep and eye on it and replace it before it busts in the middle
of BF nowhere and leaves me stranded. I don't want to be stranded.
Penny wise, pound foolish. Brake fluid: $5. Discovering a leaking
wheel cylinder in the driveway instead of the highway...
Ray
Brent P
> And three years from now when you need to get those bleeder screws
> off ... it's torch and visegrips time.
Hmm... again rust from the outside is the killer. I'll put grease over
the outside of the bleed screws threads and they don't get rusted in place.
Usually combined with anti-sieze compound on the threads. but the grease
ball is usually good enough.
Will Sill
>Will Sill wrote:
>
>> It's your vehicle - do what you like. Personally I would not think of
>> opening up a sealed system at every oil change. The risk of
>> contamination AND getting moisture in the system is MUCH greater than
>> if you just left it alone.
Steve, bristling with indignation, writes:
>Absurd. Brake fluid level should be checked EVERY oil change (more
>often, really). Checking the level requires opening the reservoir cap
>(trying to guess the level in so-called see-through master cylinder
>reservoirs is not reliable). Modern brake systems are no more "sealed"
>than they were in 1960. The cap on the master cylinder keeps out splash,
>dust, and dirt, but it is not air-tight and moisture still can get in.
Systems were sealed in 1960 too, if memory serves. It's opening them
that breaks the seal. Like I said, feel free to check your BF daily
if you like.
Will Sill
Will Sill
>Did you test boiling points before mixing and after?
Nope. Beyond the scope of my experiment. Never doubted for a second
that water lowers the boiling point and that's bad. Take another look
at what I was trying to learn - and did.
>How about the boiling point of the fluid in your RV once a year?
Nope. My rv's owners manual makes NO suggestion that I should test,
boil, change or otherwise diddle with brake fluid - at ANY frequency.
Some manuals DO, and for those people I recommend they follow the
manual.
>How much does it cost to flush your brake system?
I dunno - have never done it in 50+ years as a car nut and rv'er ---
EXCEPT when I rarely had to do major service work rquiring that the
hydraulic system be opened up. Never yet suffered a fluid-related
brake problem - so I guess I am just one lucky son of a gun.
Will Sill
BenD...@mailcity.com
mike hunt
jeffgrech
that it is more for protection of the ABS system than for
failure of brake lines due to rust.
You may very well run a non ABS system "forever"
without changing the fluid. A standard system may work OK
with a little moisture, rust, etc. in the works.
However, an ABS system can / will be completely disabled
by a small particle of rust, dirt, etc.
"Mike F" <iso...@urxSpamDam.com> wrote in message
news:t3gra.2498$C5....@fe01.atl2.webusenet.com...
Mike F
ABS by decades.
Mike
"jeffgrech" <jeff...@sysim.net> wrote in message
news:1051593336.779294@localhost...
Thomas Tornblom
the clutch master cylinder in my 1984 Pantera due to excessive
rusting.
I got the car in the year 2000 and the clutch was flakey, dropping the
pedal to the floor without any clutch action about once every fourth
attempt.
I replaced the master cylinder right after getting the car and
naturally replaced all of the the fluid in the process of replacing
the cylinder.
The slave cylinder started to leak slightly last winter while I had
the engine out and the piston was probably moving in places it had
never been before and the seals failed. Checking the bore I saw that
it was severely pitted from rust and it had to be re-lined.
The car was used in Saudi Arabia (hardly a moist place) for the first
five years and has been in Sweden since.
The car has always been garaged.
Changing the brake and clutch fluid regularly is important in my book.
Thomas
Will Sill
>My limited "research" into brake fluid flush / change tells me
>that it is more for protection of the ABS system than for
>failure of brake lines due to rust.
Good that you use quote marks on "research". Duh.
>You may very well run a non ABS system "forever"
>without changing the fluid. A standard system may work OK
>with a little moisture, rust, etc. in the works.
>
>However, an ABS system can / will be completely disabled
>by a small particle of rust, dirt, etc.
I'm confused. If your ABS system "can/will be completely disabled
by a small particle of rust, dirt, etc", WHY would you periodically
open it up to create the strong possibility of introducing foreign
matter? Did you read Bill Horne's excellent post on this topic? He
concludes:
:So I stand where I was at the beginning - if the manufacturer of your
:particular vehicle says change it, change it when they say change it.
:Otherwise, you're likely to do more causing than preventing.
:
:But y'all go ahead and change your BF periodically. If you have
:problems, you can always console yourself by telling yourself, "Damn. I
:didn't periodically change it often enough" - and just ignore the
:possibility that you caused the problem by going counter to the clear
:recommendations of GM, Ford, and Chrysler.
Neil Nelson
"Mike F" <iso...@urxSpamDam.com> wrote:
> Probably valid, but this mantra to change our brake fluid precedes common
> ABS by decades.
>
> Mike
Okay, let's go back a few decades, back to the 70s and 80s.
At the Chrysler and Ford dealerships I worked at back then,
rebuilding calipers and rear wheel cylinders was done on
each and every brake job. (policy, and for good reason)
It was very common to find rust in the cylinder bores,
sometimes it was so bad and had worked to seize the pistons
to the point that the normal procedure of applying air
pressure to the caliper inlet port to pop the piston out was
in-sufficient to move the piston. In cases like this, most
mechanics had fabricated an adaptor which allowed using a
grease gun to force the piston from the bore.
(messy, but it usually worked)
Design of the seals and dust boots plays a significant role
in how fast and/or whether moisture can intrude into the
system.
Fords, Chryslers, AMC etc. using Kelsey-Hayes designs of the
time were more prone to it than (say) GM designs were.
Of course, all of this no doubt varies according to climate,
ambient humidity and frequency of usage of salt on the roads.
perhaps this all explains the variation in experience
between different postors.
Brake fluid+moisture=rust in the system, all very real.
For whomever poo-poos this fact based according to an
experiment done by hanging two nuts in a jar of brake fluid,
I would say: Your experiment is flawed. You (we) don't
know that the metals and/or alloys of the sample nuts were
of the same composition as what is in common use in brake
systems. i.e., the nuts used could have been plated for all
we know.
There was no heat cycling as one would normally find in a
typical braking system. There was no inclusion of other
contaminants which are a normal occurance of brake
components wearing. It ignores the fact that once brake
fluid becomes saturated with moisture, additional moisture
drops out of suspension and accumulates at the lowest point
in the system that it can reach.
I would also point out the phenomenon that all of the brake
service tools I own, that have and do experience incedental
contact with used brake fluid are all suffering rust damage,
whilst similar tools of the same brand and quality used in
the same work areas that do not experience incedental
contact with used brake fluid are showing no evidence of
corrosion at all.
Brent P
> I have had to replace the clutch master cylinder and rebuild (re-line)
> the clutch master cylinder in my 1984 Pantera due to excessive
> rusting.
<snip>
> The slave cylinder started to leak slightly last winter while I had
> the engine out and the piston was probably moving in places it had
> never been before and the seals failed. Checking the bore I saw that
> it was severely pitted from rust and it had to be re-lined.
Which were into areas that had not been exposed to brake fluid.. ie
in front of the piston.
> The car was used in Saudi Arabia (hardly a moist place) for the first
> five years and has been in Sweden since.
And 11 years in Sweden.
> The car has always been garaged.
But was it driven in rain or snow?
I replaced the slave cylinder on a mazda MX6 years ago, it just died
of old age, no rust to have ripped up the seal, it just wore out.
Car just had ~170K on it at the time, the fluid had never been changed
(not my car).
Brent P
> I would also point out the phenomenon that all of the brake
> service tools I own, that have and do experience incedental
> contact with used brake fluid are all suffering rust damage,
> whilst similar tools of the same brand and quality used in
> the same work areas that do not experience incedental
> contact with used brake fluid are showing no evidence of
> corrosion at all.
While it's probably once or twice year any tools I have come in
contact with brake fluid, I have flare wrenches (craftsman) that
are probably 12 years old that haven't rusted one bit, nor have
any other of the tools. However I do clean them after they are
exposed to brake fluid. Brake fluid on a metal surface out in
the air is not good thing for the metal.
Steve
>
> You know what I've concluded? People are cheap.
And stupid.
> They won't change
> their oil any sooner than they HAVE to, and it's the same with any
> fluids on their car.
Which puts their lives and those of their passengers at risk, and yet
they're perfectly willing to file class-action lawsuits against
carmakers for FAR less negligent acts.
Steve
> Steve <n...@spam.thanks> recently wrote these words:
>
>
>>Will Sill wrote:
>>
>>
>>>It's your vehicle - do what you like. Personally I would not think of
>>>opening up a sealed system at every oil change. The risk of
>>>contamination AND getting moisture in the system is MUCH greater than
>>>if you just left it alone.
>
>
> Steve, bristling with indignation, writes:
You're right I'm indignant. You're putting my life at risk by being on
the road with me.
>
>>Absurd. Brake fluid level should be checked EVERY oil change (more
>>often, really). Checking the level requires opening the reservoir cap
>>(trying to guess the level in so-called see-through master cylinder
>>reservoirs is not reliable). Modern brake systems are no more "sealed"
>>than they were in 1960. The cap on the master cylinder keeps out splash,
>>dust, and dirt, but it is not air-tight and moisture still can get in.
>
>
> Systems were sealed in 1960 too, if memory serves. It's opening them
> that breaks the seal. Like I said, feel free to check your BF daily
> if you like.
>
> Will Sill
>
I like my cars to STOP when I push the pedal, so you're bloody right
I'll check my brake fluid. And when your brakes fail because the master
cylinder is sucking air because you were afraid you'd "break the seal"
on a system that was never hermetically sealed in the first place, and
DESPITE the instructions in your owners manual to check the brake fluid
on a regular schedule, you'd better hope you're the only one maimed and
not some innocent passenger or person in another car who actually takes
care of their vehicle.
Steve
>
>>The slave cylinder started to leak slightly last winter while I had
>>the engine out and the piston was probably moving in places it had
>>never been before and the seals failed. Checking the bore I saw that
>>it was severely pitted from rust and it had to be re-lined.
>
>
> Which were into areas that had not been exposed to brake fluid.. ie
> in front of the piston.
Actually, I've seen brake MCs fail this way when they pedal is pushed
DEEPER into areas of the bore that are 100% covered in fluid- nasty
fluid that has absorbed moisture and pitted the bore.
No fluid used in a car or truck absorbs humidity more eagerly than brake
fluid. You CAN'T keep it from absorbing water, since water vapor can
migrate *through* the rubber seals in the system over time and into the
fluid that way. That is why it should be changed occasionally.
Will Sill
>I like my cars to STOP when I push the pedal, so you're bloody right
>I'll check my brake fluid. And when your brakes fail because the master
>cylinder is sucking air because you were afraid you'd "break the seal"
>on a system that was never hermetically sealed in the first place, and
>DESPITE the instructions in your owners manual to check the brake fluid
>on a regular schedule, you'd better hope you're the only one maimed and
>not some innocent passenger or person in another car who actually takes
>care of their vehicle.
Yo, Moron! I check brake fluid LEVEL on a regular basis. Apparently
you get a contrary idea out of Rectal Data Storage! The brake system
IS sealed and there is no good reason to break that seal just to look
at it.
WHERE do nitwits like this come from?
DISCLAIMER:
My advice is useless. I have no degrees and no interest in knowing
your credentials. I've never towed a 34' TT with an Intrepid but
have survived many equally stupid tricks. 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
Will Sill
>Actually, I've seen brake MCs fail this way when they pedal is pushed
>DEEPER into areas of the bore that are 100% covered in fluid- nasty
>fluid that has absorbed moisture and pitted the bore.
In view of recent experiments, I'd have to conclude you are
hallucinating - again. I too have seen pitted bores on very old
equipment, but lacking a means of analyzing what chemicals might have
been present, I would not be willing (as you and a few others are) to
say that "absorbed moisture" is the cause. In fact, our experiments
certainly strongly suggest that a mixture of BF & water does NOT
promote rust.
>No fluid used in a car or truck absorbs humidity more eagerly than brake
>fluid. You CAN'T keep it from absorbing water, since water vapor can
>migrate *through* the rubber seals in the system over time and into the
>fluid that way. That is why it should be changed occasionally.
You are entitled to your own opinions, but you are not entitled to
your own facts. All three major US manufacturers advise AGAINST
changing fluid periodically. And I have yet to see the first credible
evidence that moisture can or will enter a properly sealed hydraulic
brake system through seals and hoses. Such evidence may exist, but if
so it has not been convincingly shared.
There ARE of course good reasons to change fluid, including but not
necessarily limited to:
- racing and similar severe service applications where components are
subjected to extreme heat
- occasions when the system is opened up for parts replacement
- vehicles for which the manufacturer RECOMMENDS periodic change
- vehicles owned by anal-retentive types who would also periodically
change the air in their tires.
Will Sill
I'll try being nicer if you'll try being smarter.
Ray
changing fluid periodically. And I have yet to see the first credible
> evidence that moisture can or will enter a properly sealed hydraulic
> brake system through seals and hoses. Such evidence may exist, but if
> so it has not been convincingly shared.
Cars don't have a properly sealed system. Go look at the flimsy
little rubber gasket inside your master cylinder. Realize that
the caliper pistons move in and out. So do the wheel cylinders.
The wife's Beretta (and most 80's GMs) seem to spring small leaks
from the master cylinder on a depressingly regular basis. That's
no sealed system. (It's a poor design that wears unevenly.)
>
> There ARE of course good reasons to change fluid, including but not
> necessarily limited to:
>
> - racing and similar severe service applications where components are
> subjected to extreme heat
towing? Mountain driving?
> - vehicles owned by anal-retentive types who would also periodically
> change the air in their tires.
I'd like that. Nitrogen would help. (NASCAR joke.)
I would like someone to test the boiling point of new brake fluid
and one year old brake fluid that's been siphoned from a master
cylinder.
Let's see where the old stuff goes - maybe you're right, but considering
the black crap I pulled from a one year old car, I doubt it.
Ray
Brent P
> Actually, I've seen brake MCs fail this way when they pedal is pushed
> DEEPER into areas of the bore that are 100% covered in fluid- nasty
> fluid that has absorbed moisture and pitted the bore.
>
> No fluid used in a car or truck absorbs humidity more eagerly than brake
> fluid. You CAN'T keep it from absorbing water, since water vapor can
> migrate *through* the rubber seals in the system over time and into the
> fluid that way. That is why it should be changed occasionally.
I simply haven't seen a rusted component that was always submerged in
brake fluid. brake fluid on it, left in the air, yes. brake components
subjected to salt spray, yes. Areas completely submerged in brake fluid
no. Case in point, the master cylinder resevior on my '73. Inside surface
where the brake fluid sits, clean. Outside surface where brake fluid
occasionally gets spilled on, rusted.
BenD...@mailcity.com
change the fluid every two years/60K WOF. Why? I suggest you
collect and observe the first few ounces of fluid that comes of
of the bleeder in those situations and you will understand why.
When one considers, fleets keep their vehicles 5yrs/300K WOF and
the little time involved and the minute costs, why not?
We do the same with power steering fluid.
mike hunt
Thomas Tornblom
> In article <x0he8hb...@Hax.SE.remove-to-reply>, Thomas Tornblom wrote:
>
> > I have had to replace the clutch master cylinder and rebuild (re-line)
> > the clutch master cylinder in my 1984 Pantera due to excessive
> > rusting.
>
> <snip>
>
> > The slave cylinder started to leak slightly last winter while I had
> > the engine out and the piston was probably moving in places it had
> > never been before and the seals failed. Checking the bore I saw that
> > it was severely pitted from rust and it had to be re-lined.
>
> Which were into areas that had not been exposed to brake fluid.. ie
> in front of the piston.
There was pitting also in the area filled with fluid and it could not
be cleaned out with a simple hone.
The problem with the master cylinder was in the internal, fluid
filled, area. No fluid disappeared, it just leaked past the inner seal.
>
> > The car was used in Saudi Arabia (hardly a moist place) for the first
> > five years and has been in Sweden since.
>
> And 11 years in Sweden.
Yes, but always stored in a heated garage and never driven wintertime.
>
> > The car has always been garaged.
>
> But was it driven in rain or snow?
The only times the car has been driven in rain has been during
occasional rain showers during trips to meetings, and I doubt that
this would have happened many times. I'm positive that the car has
never been driven in snow.
The car had only 36000km on the odo when I bought the car. The car had
8000km on the odo when the previous owner bought it in Saudi. I
believe these figures are correct.
Some years the car had only been driven to the mandatory security
inspection as the previous owner was living and working abroad.
The car was only used during the summer if at all.
>
> I replaced the slave cylinder on a mazda MX6 years ago, it just died
> of old age, no rust to have ripped up the seal, it just wore out.
> Car just had ~170K on it at the time, the fluid had never been changed
> (not my car).
>
I believe that moisture in the brake and clutch systems affect seldom
driven cars more than daily drivers. The fluids are stationary and any
moisture has months to work on eating away the cylinders. On a daily
driver the fluids are always in motion and the seals rub agains the
cylinder walls and move away any moisture to other areas.
Thomas
Mike F
graduated, clear MC sides? Do you measure a cup of water when cooking your
grits by looking in the top of the clear plastic measuring cup, or by
holding the cup up to the light and looking at the water level through the
... Ta Da .... graduated, clear sides?
Mike
"Steve" <n...@spam.thanks> wrote
Allyn Boldt
"Mike F" <iso...@urxSpamDam.com> wrote in message
> What can I see better by removing the cap than by looking through the
> graduated, clear MC sides? Do you measure a cup of water when cooking your
> grits by looking in the top of the clear plastic measuring cup, or by
> holding the cup up to the light and looking at the water level through the
> ... Ta Da .... graduated, clear sides?
>
> Mike
>
Neil Nelson
tetraet...@yahoo.com (Brent P) wrote:
Seems to be related to frequency of usage. <shrugs>
Yours have been used for the entirety of ownership as much
as mine get used in a week. (they do get wiped clean after
use)
Fact remains, and note that we're only about 90 miles apart,
I've seen hundreds of rusted, rotten, cheesey brake cylinder
bores, the rust being accountable from but one source,
moisture laden brake fluid.
Brent P
>> Which were into areas that had not been exposed to brake fluid.. ie
>> in front of the piston.
> There was pitting also in the area filled with fluid and it could not
> be cleaned out with a simple hone.
The seal will not stop rust from migrating past it once it begins.
> The problem with the master cylinder was in the internal, fluid
> filled, area. No fluid disappeared, it just leaked past the inner seal.
A 16+ year old car has a rubber seal fail.... so when a seal that
isn't in braking system fails, you blame?
> The car had only 36000km on the odo when I bought the car. The car had
> 8000km on the odo when the previous owner bought it in Saudi. I
> believe these figures are correct.
It's still pushing 20 years old.
> Some years the car had only been driven to the mandatory security
> inspection as the previous owner was living and working abroad.
That's actually not good for a car, especially for moving seals.
Brent P
> In article <Jbwra.686704$S_4.732509@rwcrnsc53>,
> tetraet...@yahoo.com (Brent P) wrote:
>
>> In article <nonelson-4F9162...@newssvr26.news.prodigy.com>, Neil
>> Nelson wrote:
>>
>> > I would also point out the phenomenon that all of the brake
>> > service tools I own, that have and do experience incedental
>> > contact with used brake fluid are all suffering rust damage,
>> > whilst similar tools of the same brand and quality used in
>> > the same work areas that do not experience incedental
>> > contact with used brake fluid are showing no evidence of
>> > corrosion at all.
>>
>> While it's probably once or twice year any tools I have come in
>> contact with brake fluid, I have flare wrenches (craftsman) that
>> are probably 12 years old that haven't rusted one bit, nor have
>> any other of the tools. However I do clean them after they are
>> exposed to brake fluid. Brake fluid on a metal surface out in
>> the air is not good thing for the metal.
> Seems to be related to frequency of usage. <shrugs>
> Yours have been used for the entirety of ownership as much
> as mine get used in a week. (they do get wiped clean after
> use)
Wiping doesn't take it all off. I can still feel the brake fluid
on the tools much of the time after wiping them with a rag. I generally
put all the stuff I use in a bucket of water and wash the tools, and
such that I used followed by a good drying.
Daniel J. Stern
> I simply haven't seen a rusted component that was always submerged in
> brake fluid.
Then you haven't looked deeply enough.
DS
Neil Nelson
<hKzra.133988$gK.2...@rwcrnsc52.ops.asp.att.net>,
tetraet...@yahoo.com (Brent P) wrote:
Yup, it's that same slimey stickeyness as anti-freeze.
Steve
> Steve <n...@spam.thanks> recently wrote these words:
>
>
>
>>I like my cars to STOP when I push the pedal, so you're bloody right
>>I'll check my brake fluid. And when your brakes fail because the master
>>cylinder is sucking air because you were afraid you'd "break the seal"
>>on a system that was never hermetically sealed in the first place, and
>>DESPITE the instructions in your owners manual to check the brake fluid
>>on a regular schedule, you'd better hope you're the only one maimed and
>>not some innocent passenger or person in another car who actually takes
>>care of their vehicle.
>
>
> Yo, Moron! I check brake fluid LEVEL on a regular basis.
Not without un-capping the MC you don't. Are you actually seeing a fluid
line on that plastic MC, or just a stain?
> you get a contrary idea out of Rectal Data Storage!
You should know about that.
>The brake system
> IS sealed and there is no good reason to break that seal just to look
> at it.
>
You GOTTA be a troll I haven't encountered before. Student-Mechanic or
Cass under a new name?
The brake system is NOT "sealed" anymore than the crankcase is "sealed"
when the oil filler cap is on. Are you afraid to "break the seal" by
pulling the dipstick out? Probably. Betcha never check your oil either.
Steve
> You are entitled to your own opinions, but you are not entitled to
> your own facts. All three major US manufacturers advise AGAINST
> changing fluid periodically.
Bullhonk.
> And I have yet to see the first credible
> evidence that moisture can or will enter a properly sealed hydraulic
> brake system through seals and hoses. Such evidence may exist, but if
> so it has not been convincingly shared.
Try this little thought-exercise:
Do wheel cylinders and calipers move in and out under normal operation?
(yes). Can moisture come into contact with the wheel cylinder or caliper
cylinder wall while the piston is RETRACTED? (yes) The next time you
step on the brakes, do you REALLY believe that the wheel cylinder seal
*really* scrapes 100% of the water molecules off the cylinder wall?
(Duuuuuuhhhhhhh no.)
If that doesn't convince you, then I suggest you get off the computer,
and GET UNDER A CAR once in a while. Restore a few. Maintain your own.
Look inside a wheel cylinder with 150,000 miles and 15 years of the same
fluid, even if it has never leaked, and you'll find plenty of corrosion.
Analyze the fluid, and you'll find plenty of water.
>
> Will Sill
> I'll try being nicer if you'll try being smarter.
Why bother, you can out-dumb ANYONE.
Steve
I've seen plenty, and I don't even live in the Rust Belt. DOT3 brake
fluid is INCREDIBLY hygroscopic. It WILL absorb water, even in a
"closed" (not "sealed" since there is no such thing) brake system.
Steve
And the "clear" master cylinder reservoir on any new car will be opaque
after 5 years. Been there, seen that (repeatedly).
Brent P
> And the "clear" master cylinder reservoir on any new car will be opaque
> after 5 years. Been there, seen that (repeatedly).
Still transulcent on my '97. Still transulcent on my '86.
Will Sill
<n...@spam.thanks> recently wrote these words about checking BF level:
>Not without un-capping the MC you don't. Are you actually seeing a fluid
>line on that plastic MC, or just a stain?
Stains don't jiggle when you rock the vehicle.
>The brake system is NOT "sealed" anymore than the crankcase is "sealed"
>when the oil filler cap is on.
Your assertion that the brake system isn't sealed is false. The
diaphragm under the lid assures there is no direct contact between air
& fluid EXCEPT when you open the system to look inside. I suppose
it's technically (though remotely) POSSIBLE that an insignificant
amount of moisture could eventually worm its way through hoses, seals
and the above-mentioned diaphragm. Before that happens, I predict you
will have either lived long enough to grow up or will have competed
for a Darwin Award in some manner.
There are REASONS why the Big Three US car makers advise against
changing the fluid - the chief one being that the chance of
contamination increases when you open it up.
>Are you afraid to "break the seal" by
>pulling the dipstick out? Probably. Betcha never check your oil either.
The crankcase isn't "sealed, and is a horse of a different hue
entirely. The fact that you tried to make a comparison is additional
proof that you have no clue what you're talking about.
Though the competition is heavy right now, you definitely have my vote
for Dork of the Week. I have well over 50 years of hands-on
experience with motor vehicles, and you strike me as the sort of
know-it-all juvenile who has virtually NO experience and even less
technical training.
DISCLAIMER:
My advice is useless. I have no degrees and no interest in knowing
your credentials. I've never towed a 34' TT with an Intrepid but
have survived many equally stupid tricks. 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. I do have a
well-honed BS detector, and you've rung it several times.
Will Sill
bro...@shaw.ca
Steve wrote:
> Not without un-capping the MC you don't. Are you actually seeing a fluid
> line on that plastic MC, or just a stain?
>
Speaking of checking fluid levels by looking through plastic, we just had a
situation at one of our car washes. We have a twin cylinder upright air
compressor that has a clear sight glass for the oil level right next to the
dip stick. The staff are required to complete a daily check list, one item
being the oil level in the compressor. EVERYONE, including myself, just used
the sight glass and the level showed full - it was right at the midpoint and
along the red line provided as a gauge.
One evening I got a call at home that the compressor started making a very
loud racket and then stopped. The next morning, the day manager, called me
to tell me that the rods were hanging outside the block - it blew up
completely. The crank journals and the connecting rod ends were burnt blue -
lack of lubrication.
It turns out the crankcase was OUT OF OIL - nothing appreciable spilled when
the thing blew up. When we looked at the sight glass, it still showed the
oil right up to the full line, this being right next to a large hole in the
block. The oil did in fact stain the sight indicator. The compressor was
complete junk and the oil level was still okay.
No one was at fault - we were all taken in by the quick visual inspection.
Simple remedy - buy a new compressor and start using the dip stick. In this
scenario, the only thing affected was my wallet. WHAT IF this was your
empty master cylinder YOU were SURE was full??????????
Ask me if I will ever believe a quick peak through a plastic see through
container!!
Myron
bill horne
>
> Will Sill wrote:
>
> > You are entitled to your own opinions, but you are not entitled to
> > your own facts. All three major US manufacturers advise AGAINST
> > changing fluid periodically.
>
> Bullhonk.
Here it is again:
And at the 2001 annual brake symposium, Ford says:
-------------------------------------------------------
Ford does not recommend changing DOT 3 fluid or flushing the system.
Ford says their recommendation is a "risk vs. benefit" assessment
because there's a potential for doing more damage than good.
--------------------------------------------------
risk exceeds benefit.
And:
--------------------------------------------------
Ford says their brake systems are engineered to tolerate brake fluid
contamination of up to three percent moisture without fluid boil (which
is close to the saturation point for DOT 3 brake fluid). If the fluid
has more moisture, it probably has some water in it and should be
changed.
Ford said they measured the water content in seven- to 10-year-old Ford
vehicles and found that the water content was actually quite low: only 1
to 1-1/2 percent. So based on their findings and the design target of
three percent water, they see no need to change the fluid for preventive
maintenance.
---------------------------------------------------
1-1.5% in 7 to 10 year old vehicles. Where's all this alleged brake line
osmosis?
Then the GM rep says:
--------------------------------------------------
GM's position of brake fluid is that they do not recommend changing it
on most vehicles. The only exceptions are Metro and Tracker models. GM
brake systems are sealed and should not need flushing. GM's goal is to
reduce maintenance requirements, not add them.
--------------------------------------------------
do not recommend. sealed.
DaimlerChrysler says:
---------------------------------------
With the exception of the Viper, all current domestic DaimlerChrysler
products use high temperature DOW 1000 DOT 3 brake fluid, which has a
boiling temperature of 550ûF and surpasses the government's minimum
performance requirements for DOT 3 brake fluid. DaimlerChrysler says
its fluid can absorb up to 3% water and still meet the DOT 3
specifications for boiling temperature.
Consequently, they see no reason to change the fluid for preventive
maintenance - contrary to most aftermarket recommendations.
-----------------------------------------
no reason to change
That's all pretty clear and unambiguous to me.
--
bill
Theory don't mean squat if it don't work.
bill horne
Balls. I have no trouble at all seeing the BF level in my 83 Chevy
truck. That's 20 years - 4 times longer than 5. No trouble with the
little teal green trucklet, either - which was new 7 years ago.
You must of been there and seen that with shitty vehicles. Repeatedly.
bill horne
I fail to see how this applies to a plastic MC reservoir, where you're
actually looking at the fluid in the reservoir, and not some tapped-off
portion of it. You might as well try to convince me that I don't know
how much Dog is left in the bottle unless I peer down the neck.
bro...@shaw.ca
of the compressor. It is a virtual window into the oil contained in the compressor
head. This twin cylinder compressor is a stand alone unit and sits on top of the
reservoir tank and is driven by a 220 volt electric motor.
BTW, if your DOG stains glass the same as a petroleum products can, best you switch
intoxicants.
Myron
Clyde Merkswitch
that could potentially damage the ABS and traction control components,
such as the pump and valve body assembly. They even cover the service
under their 4 year/50k maintenance program.
As a precaution, I did a flush on my '96 Ford Escort with 80k miles
earlier this year. It was the first time in the life of the car that
such a service had been performed. The fluid that came out was opaque
BLACK when viewed in a glass Snapple bottle. That's all the proof I need.
For a 'sealed' system the fluid sure did pick up a lot of dirt.
-Merk
> boiling temperature of 550ūF and surpasses the government's minimum
Brent P
> As a precaution, I did a flush on my '96 Ford Escort with 80k miles
> earlier this year. It was the first time in the life of the car that
> such a service had been performed. The fluid that came out was opaque
> BLACK when viewed in a glass Snapple bottle. That's all the proof I need.
> For a 'sealed' system the fluid sure did pick up a lot of dirt.
I'll guess the black material was actually in the system to begin with.
Material lost from the hoses and seals. Rubber that has decayed.
Thomas Tornblom
> Will Sill wrote:
> > Steve <n...@spam.thanks> recently wrote these words:
> >
>
[...]
>
> Not without un-capping the MC you don't. Are you actually seeing a
> fluid line on that plastic MC, or just a stain?
The plastic MC fluid containers on all my cars, 1992 VW Golf, 1995
Audi A6, 1984 DeTomaso Pantera can be wiggled sligtly so that the
fluid surface is easily verified without pulling the cap.
phil Willen
completely while descending the winding road leading
in to Zion Nat. Park. The trailer I had hitched to the back
of my 49 Olds Rocket 88 made it more interesting since
the emergency brake didn't do a thing. Having the wife and
kids in the car didn't help much.
I made it down, changed my shorts and contacted
a mechanic in the nearest town. The wheel cylinders
were pocked with rust marks, letting the fluid drain away
at a most inopportune time. Brake fluid has an affinity for
water. That's why you shouldn't use that open can of fluid
that's been sitting on the shelf for a while.
Will Sill
>No one was at fault - we were all taken in by the quick visual inspection.
>Simple remedy - buy a new compressor and start using the dip stick. In this
>scenario, the only thing affected was my wallet. WHAT IF this was your
>empty master cylinder YOU were SURE was full??????????
>
>Ask me if I will ever believe a quick peak through a plastic see through
>container!!
I understand your attitude but remind you that a slight jiggling of
the vehicle removes any doubt about the fluid level in a master
cylnder.
Will Sill
bill horne
>
> Perhaps I was not clear - the sight glass is located right in the side of the block
> of the compressor. It is a virtual window into the oil contained in the compressor
> head. This twin cylinder compressor is a stand alone unit and sits on top of the
> reservoir tank and is driven by a 220 volt electric motor.
>
> BTW, if your DOG stains glass the same as a petroleum products can, best you switch
> intoxicants.
>
> Myron
You were perfectly clear - I just disagree that your comparison is
relevant. I also have a two cylinder air compressor with a "virtual"
window - but my MC reservoir is Not a virtual window. Which was my point
- what I see in the MC reservoir is what is in there.
Steve
And my 93 was too opacified to trust by 1998. As is every MC reservoir
I've ever seen in a junkyard or on a car more than 5 years old. Maybe
its being in a climate where the summer highs are always in the low
100s, giving under-hood temps well over 200F for much of the year. But
NO translucent under-hood plastic seems to stay that way.
Da Chief
parts, there is a thought someone might try. I had a motorcycle in my
younger days (long ago and far away) that had plastic lenses in the speedo
and tach. I refused to buy the glass lenses (cost and time were an issue).
So, just before I would leave the house I would put one small drop of baby
oil on my finger and rub the lens which instantly made it clear. Maybe
someone could use a fine clear machine oil on just enough of the surface to
get a "window of opportunity"?
--
Shelby Foles, srf...@bellsouth.net
"Steve" <n...@spam.thanks> wrote in message
news:OLmdneyf_MA...@texas.net...
Steve
> In a desperate attempt to qualify as Dork of the Day, Steve
> <n...@spam.thanks> recently wrote these words about checking BF level:
>
>
>>Not without un-capping the MC you don't. Are you actually seeing a fluid
>>line on that plastic MC, or just a stain?
>
>
> Stains don't jiggle when you rock the vehicle.
>
>
>>The brake system is NOT "sealed" anymore than the crankcase is "sealed"
>>when the oil filler cap is on.
>
>
> Your assertion that the brake system isn't sealed is false. The
> diaphragm under the lid assures there is no direct contact between air
> & fluid EXCEPT when you open the system to look inside.
It is a CLOSED system, not a SEALED system. There's a huge difference.
The refrigerant system on your home air-conditioner is hermetically
sealed (welded closed, completely impermeable seal). The refrigerant
system on your car air-conditioner is sealed (rubber and shaft seals
that leak, but do so at a tiny, tiny rate compared to system volume and
do NOT allow moisture intrusion because the system is pressurized.).
By contrast, your braking system is closed by PERMEABLE seals, and
operates at exactly atmospheric pressure on the reservoir side of the
master cylinder. I probably shouldn't have used the engine as an example
since it has forced-air ventilation (PCV). A better comparison would be
the power steering reservoir or the automatic transmission.
I suppose
> it's technically (though remotely) POSSIBLE that an insignificant
> amount of moisture could eventually worm its way through hoses, seals
> and the above-mentioned diaphragm. Before that happens, I predict you
> will have either lived long enough to grow up or will have competed
> for a Darwin Award in some manner.
Be an ass all you want, but I'm going to stick to the facts here. I've
been working on braking systems (and cars in general) for 25 years. Even
though I'm well outside the rust belt, I've seen LOTS of brake hardware
with moisture damage. Its not supposition or hypothesis that brake fluid
is EXTREMELY hygroscopic. Thats a fact, and the damage that results is a
fact.
>
> There are REASONS why the Big Three US car makers advise against
> changing the fluid - the chief one being that the chance of
> contamination increases when you open it up.
Flatly wrong. It is only closed, not sealed, to start with, and unless
you shake a filthy shop rag over the open reservoir, you are NOT going
to get any contaminants in it.
>
> Though the competition is heavy right now, you definitely have my vote
> for Dork of the Week. I have well over 50 years of hands-on
> experience with motor vehicles, and you strike me as the sort of
> know-it-all juvenile who has virtually NO experience and even less
> technical training.
Well, I've got about 25 years of spare time tinkering with cars, and
along the way I picked up a bachelor's and master's degree in
engineering. I am not a snob that thinks anyone without a degree is
incompetent- some of the most intelligent people I've ever met had
high-school educations are less. But you're wrong about both my
experience and training.
Will Sill
>>>And the "clear" master cylinder reservoir on any new car will be opaque
>>>after 5 years. Been there, seen that (repeatedly).
And later:
>And my 93 was too opacified to trust by 1998. As is every MC reservoir
>I've ever seen in a junkyard or on a car more than 5 years old. Maybe
>its being in a climate where the summer highs are always in the low
>100s, giving under-hood temps well over 200F for much of the year. But
>NO translucent under-hood plastic seems to stay that way.
And all mall pet shops are evil, too.
Have your seeing eye dog check the level. I just checked the level in
our '91 GMC by looking at it an jiggling the tuck a bit to verify what
I was seeing through the translucent reservoir. Must be my truck isn't
old enuf.
EGAD!
Will Sill
Steve
Not for me. Its hard enough to see when those reservoirs are new, but
when they're a few years old its practically impossible to see anything
through them. And since tons of reservoirs are metal or black plastic,
the point is moot for them.
Steve
Brake fluid turns DARK brown (nearly black) as it absorbs moisture. I
agree a lot of what you see may be rubber and iron oxide caused by the
contaminated fluid, but a lot of it is also simply the contaminated fluid.
Will Sill
wrote these words:
>Brake fluid turns DARK brown (nearly black) as it absorbs moisture. I
>agree a lot of what you see may be rubber and iron oxide caused by the
>contaminated fluid, but a lot of it is also simply the contaminated fluid.
Perhaps, then, you can explain why a 50/50 mixture of water and BF
sitting open in my basement for 11 months is still - as far as the eye
can detect - the same light amber color it had when first poured.
Now that Bahgdad Bob is of the air, maybe you could get a job taking
his place. If bullshit was money, you could buy out Bill Gates.
Will Sill
bill horne
>
> Brent P wrote:
> > In article <uGIra.674988$L1.192520@sccrnsc02>, Clyde Merkswitch wrote:
> >
> >
> >>As a precaution, I did a flush on my '96 Ford Escort with 80k miles
> >>earlier this year. It was the first time in the life of the car that
> >>such a service had been performed. The fluid that came out was opaque
> >>BLACK when viewed in a glass Snapple bottle. That's all the proof I need.
> >
> >
> >
> >>For a 'sealed' system the fluid sure did pick up a lot of dirt.
> >
> >
> > I'll guess the black material was actually in the system to begin with.
> > Material lost from the hoses and seals. Rubber that has decayed.
> >
> >
>
> Brake fluid turns DARK brown (nearly black) as it absorbs moisture.
More total bullshit. I have a pimento jar of BF containing 25% water,
and it's been there since last July. It's the same coler it was when it
came out of the can.
> I
> agree a lot of what you see may be rubber and iron oxide caused by the
> contaminated fluid, but a lot of it is also simply the contaminated fluid.
Will Sill
recently wrote these words in an attempt to make sure no competitor
can pass him:
>>>The brake system is NOT "sealed" anymore than the crankcase is "sealed"
>>>when the oil filler cap is on.
When I challenged his unfounded assumptions by writing:
>> Your assertion that the brake system isn't sealed is false. The
>> diaphragm under the lid assures there is no direct contact between air
>> & fluid EXCEPT when you open the system to look inside.
He responds with:
>It is a CLOSED system, not a SEALED system. There's a huge difference.
>The refrigerant system on your home air-conditioner is hermetically
>sealed (welded closed, completely impermeable seal). The refrigerant
>system on your car air-conditioner is sealed (rubber and shaft seals
>that leak, but do so at a tiny, tiny rate compared to system volume and
>do NOT allow moisture intrusion because the system is pressurized.).
EGAD, is there no end to your foolishness? You are digging yourself
deeper and deeper. Brake systems are _sealed_. Comparisons with
refrigerant systems are misguided.
>By contrast, your braking system is closed by PERMEABLE seals, and
>operates at exactly atmospheric pressure on the reservoir side of the
>master cylinder.
Under what conditions are brake system diaphragms, hoses and seals
"permeable" enough to allow measurable amounts of moisture to enter
the system? How much? Under what conditions? How do you know?
> . .I probably shouldn't have used the engine as an example
>since it has forced-air ventilation (PCV).
There's another reason crankcase ventilation is irrelevant - there is
no "forced air ventilation" involved. Instead the PVC system creates a
slight negative pressure in order to carry off any blow by products
without allowing them to escape into the air.
> A better comparison would be
>the power steering reservoir or the automatic transmission.
Not true either. Unlike the BF master cylinder, the PS fluid
reservoir IS vented to the atmosphere.
I wrote:
> I suppose
>> it's technically (though remotely) POSSIBLE that an insignificant
>> amount of moisture could eventually worm its way through hoses, seals
>> and the above-mentioned diaphragm. Before that happens, I predict you
>> will have either lived long enough to grow up or will have competed
>> for a Darwin Award in some manner.
Says Steve:
>Be an ass all you want, but I'm going to stick to the facts here. I've
>been working on braking systems (and cars in general) for 25 years. Even
>though I'm well outside the rust belt, I've seen LOTS of brake hardware
>with moisture damage. Its not supposition or hypothesis that brake fluid
>is EXTREMELY hygroscopic. Thats a fact, and the damage that results is a
>fact.
It is of course possible for moisture to enter around defective,
worn-out brake cylinder seals. For that reason, virtually every
competent person recommends flushing and changing BF when the system
is opened up to rebuild or replace cylinders. What is simply not
possible is for significant amounts to enter through the reservoir
diaphragm or hoses, as you and Chris Bryant have claimed.
I said:
>> There are REASONS why the Big Three US car makers advise against
>> changing the fluid - the chief one being that the chance of
>> contamination increases when you open it up.
Steve:
>Flatly wrong. It is only closed, not sealed, to start with, and unless
>you shake a filthy shop rag over the open reservoir, you are NOT going
>to get any contaminants in it.
In the first place, the claim is not wrong, as Bill Horne's recent
post proved. In the second place, you yourself have attempted to
characterize BF as VERY hydroscopic, leading to a justifiable
conclusion that if you open the reservoir to look at it frequently,
you'll inevitably have moisture-contaminated BF. Further, unless you
steam clean the engine bay before popping that lid, you WILL disturb
dust and crud by doing so.
Based on your juvenile attitude and apparent lack of knowledge, I
wrote:
>> Though the competition is heavy right now, you definitely have my vote
>> for Dork of the Week. I have well over 50 years of hands-on
>> experience with motor vehicles, and you strike me as the sort of
>> know-it-all juvenile who has virtually NO experience and even less
>> technical training.
And now you say:
>Well, I've got about 25 years of spare time tinkering with cars, and
>along the way I picked up a bachelor's and master's degree in
>engineering. I am not a snob that thinks anyone without a degree is
>incompetent- some of the most intelligent people I've ever met had
>high-school educations are less. But you're wrong about both my
>experience and training.
So, I misjudged your training but not your knowledge or attitude. A
thousand pardons. Do your homework a little better before continuing
to give out misinformation.
Will ---- the Curmudgeon of Sill Hill
Before flaming, pause. I post to help rv'ers and annoy the snot
out of morons, idjits, fools and bozos - - and to irk their ilk.
Often, I do both at once.
Chas Hurst
"Steve" <n...@spam.thanks> wrote in message
A number of brake MC have a rubber bladder or bellows incorporated to the
lid or cap. My ' 68 Olds has one. These systems are sealed. The
bladder/bellows expands as the fluid level drops. Have you never seen this?
Chas Hurst
bill horne
> Not for me. Its hard enough to see when those reservoirs are new, but
> when they're a few years old its practically impossible to see anything
> through them. And since tons of reservoirs are metal or black plastic,
> the point is moot for them.
Just because you're blind doesn't mean everyone is. I can see the BF
level in my MC just fine - even without my glasses. And it's not even
close to practically impossible for me to see the BF level in my 20-year
old Chevy. And it's not hard to see the BS in your MC, either. I
conclude that your brain fluid is contaminated, and should be replaced.
bill horne
Mine's 20 years old. I guess it's not old enough either.
Steve
> Steve <n...@spam.thanks>, that fountain of misinformation, recently
> wrote these words:
>
>
>>Brake fluid turns DARK brown (nearly black) as it absorbs moisture. I
>>agree a lot of what you see may be rubber and iron oxide caused by the
>>contaminated fluid, but a lot of it is also simply the contaminated fluid.
>
>
> Perhaps, then, you can explain why a 50/50 mixture of water and BF
> sitting open in my basement for 11 months is still - as far as the eye
> can detect - the same light amber color it had when first poured
Because youre making this cr*p up as you go?
.
>
> Now that Bahgdad Bob is of the air, maybe you could get a job taking
> his place. If bullshit was money, you could buy out Bill Gates.
>
> Will Sill
>
Pot, meet kettle.
You really ARE Cass in drag. Admit it.
Brent P
Although black is different than dark brown. Old, moisture ridden fluid
I've found is dark brown when taken out and put in a separate container
as described. I've seen fluid that looked blackish through the plastic
but once drained was just brown. For it to be an opaque black once
drained and placed in a glass bottle something had to be dissolved in the
fluid, otherwise it would have still be a brown/rust color.
Of course that doesn't mean dirt and crap didn't get in the master
cylinder resovoir. I've seen that.
Brent P
There is one condition that I have trouble reading the level through
the plastic. When I've got brand-new-perfectly clean dot 4 brake fluid in
the mustang. It's about as translucent as the container. I can still see
it but it's hard to read. However checking it as it gets a bit dark out
and shining a flashlight through makes for a clear, obvious color
difference that shows the level.
Steve
>
> A number of brake MC have a rubber bladder or bellows incorporated to the
> lid or cap. My ' 68 Olds has one. These systems are sealed. The
> bladder/bellows expands as the fluid level drops. Have you never seen this?
>
> Chas Hurst
>
>
Of course. The point is that the system isn't sealed, its simply closed
to a level reasonable enough to prevent intrusion of dirt and water.
That thin rubber bellows is *quite* permeable to water vapor, though,
and the presence of a very hygroscopic fluid on the other side of it
serves to speed the process. The idea that opening the cap for 10
seconds to check the fluid will allow massive contamination of the fluid
is absurd, but the resident troll seems married to that idea.
Steve
> Steve <n...@spam.thanks>, having already qualified for Dork of the Week,
> recently wrote these words in an attempt to make sure no competitor
> can pass him:
>
>
>>>>The brake system is NOT "sealed" anymore than the crankcase is "sealed"
>>>>when the oil filler cap is on.
>
>
> When I challenged his unfounded assumptions by writing:
>
>>>Your assertion that the brake system isn't sealed is false. The
>>>diaphragm under the lid assures there is no direct contact between air
>>>& fluid EXCEPT when you open the system to look inside.
>
>
> He responds with:
>
>>It is a CLOSED system, not a SEALED system. There's a huge difference.
>>The refrigerant system on your home air-conditioner is hermetically
>>sealed (welded closed, completely impermeable seal). The refrigerant
>>system on your car air-conditioner is sealed (rubber and shaft seals
>>that leak, but do so at a tiny, tiny rate compared to system volume and
>>do NOT allow moisture intrusion because the system is pressurized.).
>
>
> EGAD, is there no end to your foolishness? You are digging yourself
> deeper and deeper. Brake systems are _sealed_. Comparisons with
> refrigerant systems are misguided.
You are so clueless its unbelievable. How do you add brake fluid as your
pads wear down (a normal condition) without opening the system? Are you
in dire terror that the system is corrupted the first time you have to
add fluid?
> Under what conditions are brake system diaphragms, hoses and seals
> "permeable" enough to allow measurable amounts of moisture to enter
> the system?
All conditions. Rubber compounds, both natural and synthetic, are
permeable to lots of things, including water vapor.
> How much?
Enough to corrode parts and to drastically lower the boiling point of
brake fluid within a few months to a few years, depending upon climate.
>Under what conditions?
All conditions (again).
> How do you know?
Because I don't have my head under a rock. Because I've SEEN the
corrosion damage in systems that were still full of fluid and not yet
leaking fluid out. If the fluid wasn't leaking out, how did the water
get in, if not past fully functioning seals? Have you done the thought
experiment I suggested, or are you digging a deeper hole in the sand for
your very large head?
>
>
> There's another reason crankcase ventilation is irrelevant - there is
> no "forced air ventilation" involved. Instead the PVC system creates a
> slight negative pressure in order to carry off any blow by products
> without allowing them to escape into the air.
Semantic weaselling. Like I said, the flow is forced. So what if the
forcing function is a vacuum instead of positive pressure. Think
"forced" as a synonmym for "caused" if it makes you feel smarter.
> What is simply not
> possible is for significant amounts to enter through the reservoir
> diaphragm or hoses, as you and Chris Bryant have claimed.
Then that is where you are wrong. Such contamination is well documented
by thousands of people who are, frankly, more qualified to document it
than either one of us. The fact that I've seen the corrosion predicted
by the people who have documented it leads to my belief that their claim
is true. I'm not making this up on my own.
Chas Hurst
"Steve" <n...@spam.thanks> wrote in message
doesn't put *any* extra parts on their cars, especially ones you can't see
right off. Your suggestion that rubber is permeable has no basis in fact. I
will agree opening a M/C for a check "shouldn't" introduce any quantity of
contamination, but nothing on a car is foolproof.
Daniel J. Stern
> > Of course. The point is that the system isn't sealed, its simply closed
> > to a level reasonable enough to prevent intrusion of dirt and water.
> > That thin rubber bellows is *quite* permeable to water vapor, though,
> > and the presence of a very hygroscopic fluid on the other side of it
> > serves to speed the process.
> Horseshit! That rubber is there to keep out moisture and it works.
It does not hermetically seal the system. Steve is correct; water vapor
*does* permeate the master cylinder lid "seal".
DS
Will Sill
<n...@spam.thanks> I noticed only the following worth comenting on:
>How do you add brake fluid as your
>pads wear down (a normal condition) without opening the system?
I don't. There is enough fluid to allow for normal pad wear. If you
top off while the pads are worn down, the reservoir will have to be
opened to allow overflow when you fit new pads. If course, that's not
a issue for someone incapable of seeing the fluid level through a
translucent reservoir - and who removes the diaphragm seal monthly.
All other questions, even the irrational ones, have been answered.
Will Sill
aparently not having followed the thread, and claims concerning the
diaphragm in the MC:
>It does not hermetically seal the system. Steve is correct; water vapor
>*does* permeate the master cylinder lid "seal".
I will ask you the question asked several times earlier and answered
by nobody:
Under what conditions are brake system diaphragms, hoses and seals
"permeable" enough to allow measurable amounts of moisture to enter
the system? How much? Under what conditions? How do you know?
Will Sill
Daniel J. Stern
> Under what conditions are brake system diaphragms, hoses and seals
> "permeable" enough to allow measurable amounts of moisture to enter
> the system?
We're not discussing "diaphragms, hoses and seals" in general. We're
discussing, in specific, the diaphragm gasket integral with or sandwiched
under the brake master cylinder fluid reservoir cover(s). The design of
this diaphragm gasket varies widely. Some are obviously designed to
approach hermeticity to the degree practical in a system that must allow
for the seal to be repeatedly broken (i.e., the cover removed). Of those,
some achieve the design goal and some do not. Others are, equally
obviously, *NOT* designed to approach hermeticity at all. Off the top of
my head, I can think of several dozen master cylinder/reservoir designs of
each of these classifications with which I have sufficient personal
experience to make this assertion. It takes no special knowledge or tools
to make the determination, either -- just a basic understanding of what
constitutes a hermetic seal and how it is made, a working pair of eyes and
a functional brain.
The seals that do not approach hermeticity -- by definition -- readily
permit ambient water vapor to migrate into the reservoir, as for example
across the seal-to-reservoir and seal-to-cap junctions. The hygroscopic
nature of glycol-based brake fluids, as an earlier poster indicated, tend
to accelerate this process and increase the degree to which it occurs.
Obviously, higher levels of ambient humidity will also accelerate and
increase the process.
Should every effort be made to exclude ambient moisture from the brake
system at the reservoir-to-cap seal? Absolutely. The fact of the matter is
that some designs achieve better attainment of this goal than others.
> How do you know?
There are several reliable and accurate tools readily available on the
market for testing the moisture content of brake fluid. Just as there are
people geeky enough to run engine oil filters through all sorts of tests
and inspection processes, there are people geeky enough to set up
controlled experiments with brake master cylinders. Some of those geeks
get paid for what they do, by the automakers.
DS
Steve
> Amidst a continuing flood of clueless ranting by Steve
> <n...@spam.thanks> I noticed only the following worth comenting on:
>
>
>>How do you add brake fluid as your
>>pads wear down (a normal condition) without opening the system?
>
>
> I don't. There is enough fluid to allow for normal pad wear. If you
> top off while the pads are worn down, the reservoir will have to be
> opened to allow overflow when you fit new pads.
If you follow the correct procedure, you'll crack the bleeder screws
open as you press the pistons back into the calipers. Failing to do this
can (at worst) damage the valving in some ABS systems or (at a minimum)
push dirty fluid from the calipers back up into the proportioning
valves, safety isolation valves, and master cylinder. This also has the
benefit of changing a small amount of old brake fluid every time you do
brake pads.
But you don't believe in that, I'm sure you just crank down on your 8"
C-clamp, ram that contaminated fluid back into the plumbing and damn the
torpedoes. Its SO comforting to know that cars maintained that way are
out there following me down the highway at 70 mph.
C. E. White
http://www.csaa.com/global/articledetail/0,8055,1004010302%257C2026,00.html :
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 http://www.babcox.com/editorial/bf/bf80112.htm :
BRAKE FLUID
Ford does not recommend changing DOT 3 fluid or flushing the system. Ford says
their recommendation is a "risk vs. benefit" assessment because there's a
potential for doing more damage than good. If sediment or contamination from
the master cylinder is pushed through the ABS unit, it can cause big problems.
Flushing the system also increases the risk of air entrapment and leaks, says
Ford.
Ford says their brake systems are engineered to tolerate brake fluid
contamination of up to three percent moisture without fluid boil (which is
close to the saturation point for DOT 3 brake fluid). If the fluid has more
moisture, it probably has some water in it and should be changed.
Ford said they measured the water content in seven- to 10-year-old Ford
vehicles and found that the water content was actually quite low: only 1 to
1-1/2 percent. So based on their findings and the design target of three
percent water, they see no need to change the fluid for preventive
maintenance.
Does pushing the caliper pistons in when changing the pads push contaminants
from the calipers back toward the ABS unit or master cylinder? Ford says no.
There's not enough movement or migration to cause a problem.
BRAKE FLUID
GM's position of brake fluid is that they do not recommend changing it on most
vehicles. The only exceptions are Metro and Tracker models. GM brake systems
are sealed and should not need flushing. GM's goal is to reduce maintenance
requirements, not add them.
See also
http://www.babcox.com/editorial/bf/bf89950.htm
http://www.babcox.com/editorial/bf/bf40142.htm
Will Sill
purporting to justify his conclusion that the BF reservoir diaphragm
is "permeable" - to wit:
>We're not discussing "diaphragms, hoses and seals" in general. We're
>discussing, in specific, the diaphragm gasket integral with or sandwiched
>under the brake master cylinder fluid reservoir cover(s). The design of
>this diaphragm gasket varies widely. Some are obviously designed to
>approach hermeticity to the degree practical in a system that must allow
>for the seal to be repeatedly broken (i.e., the cover removed). Of those,
>some achieve the design goal and some do not. Others are, equally
>obviously, *NOT* designed to approach hermeticity at all. Off the top of
>my head, I can think of several dozen master cylinder/reservoir designs of
>each of these classifications with which I have sufficient personal
>experience to make this assertion. It takes no special knowledge or tools
>to make the determination, either -- just a basic understanding of what
>constitutes a hermetic seal and how it is made, a working pair of eyes and
>a functional brain.
The latter - along with crdible DATA - seems to be in short supply on
this thread!
>The seals that do not approach hermeticity -- by definition -- readily
>permit ambient water vapor to migrate into the reservoir, as for example
>across the seal-to-reservoir and seal-to-cap junctions. The hygroscopic
>nature of glycol-based brake fluids, as an earlier poster indicated, tend
>to accelerate this process and increase the degree to which it occurs.
>Obviously, higher levels of ambient humidity will also accelerate and
>increase the process.
>
>Should every effort be made to exclude ambient moisture from the brake
>system at the reservoir-to-cap seal? Absolutely. The fact of the matter is
>that some designs achieve better attainment of this goal than others.
>
>> How do you know?
>
>There are several reliable and accurate tools readily available on the
>market for testing the moisture content of brake fluid. Just as there are
>people geeky enough to run engine oil filters through all sorts of tests
>and inspection processes, there are people geeky enough to set up
>controlled experiments with brake master cylinders. Some of those geeks
>get paid for what they do, by the automakers.
"We" - being the people who started this 'discussion', were in fact
discussing MORE than just the diaphragm. The exact wording of the
question (most of which the above comments avoided) was:
:Under what conditions are brake system diaphragms, hoses and seals
:"permeable" enough to allow measurable amounts of moisture to enter
:the system? How much? Under what conditions? How do you know?
If many words constituted a credible answer, it would have been fully
answered a year ago. To date, I have seen NO credible answers to the
"how much" part of the question. No responsible person has claimed
that brake systems are totally and absolutely impervious
("hermetically sealed") against moisture contamination - only that the
system is sealed and should be OK unless you mess with it.
::sigh::
Will Sill
Will Sill
industry sources confirming that the Big Three advise AGAINST periodic
changing of BF, but then included links (below) that contradict that
POV. To wit:
>http://www.babcox.com/editorial/bf/bf89950.htm
>http://www.babcox.com/editorial/bf/bf40142.htm
If your goal was to further confuse readers, I can see why you'd do
that, but I will ask you the same question asked of others:
:Under what conditions are brake system diaphragms, hoses and seals
:"permeable" enough to allow measurable amounts of moisture to enter
:the system? How much? Under what conditions? How do you know?
To date, NOBODY has presented credible, quantified, and verified FACTS
in answer to that question.
I realize there is a lot of contradictory bafflegab out there, so I
don't blame people for being misled. That is, I don't blame them
until they start demonizing people like myself who do not swallow
myths and legends. I started this current thread with FACTS from an
actual test intended to evaluate a number of claims that are now
proved WRONG. IMO, those who continue to claim that brake system
diaphragms, hoses and seals are actually "permeable" enough to allow
measurable amounts of moisture to enter the system have an obligation
to answer the question or admit they don't know.
Steve
> No responsible person has claimed
> that brake systems are totally and absolutely impervious
> ("hermetically sealed") against moisture contamination - only that the
> system is sealed and should be OK unless you mess with it.
>
How many of us have to tell you that we've seen the damaged cylinder
bores that result from NORMAL moisture intrusion with our very own eyes?
In my case, I've seen it many times over many years. Does it happen
immediately? No. Can a car go many years without suffering a brake
failure? Yes, I have several that have myself. Does knowing that
moisture intrusion DOES happen make me feel safer periodically changing
fluid (or at least the amount that comes out when I re-compress calipers
during a pad change)? Yes. There is NO WAY that the act of changing
brake fluid could possibly introduce MORE contaminants than it gets rid
of, unless the person doing the change is utterly incompetent and washes
his shop rag out in the master cylinder.
As for the recent post that quoted Ford as saying you shouldn't worry
about re-compressing calipers without opening the bleeder, thats fine
for Ford. I have a 1993 Chrysler factory service manual that explicitly
warns NOT to re-compress calipers without opening the bleeder because of
the risk of forcing contaminated fluid back into the ABS mechanism.
bill horne
>
> In article <EOGdnZ4oLP2...@texas.net>, Steve wrote:
> > Brent P wrote:
> >> In article <uGIra.674988$L1.192520@sccrnsc02>, Clyde Merkswitch wrote:
>
> >>>As a precaution, I did a flush on my '96 Ford Escort with 80k miles
> >>>earlier this year. It was the first time in the life of the car that
> >>>such a service had been performed. The fluid that came out was opaque
> >>>BLACK when viewed in a glass Snapple bottle. That's all the proof I need.
>
> >>>For a 'sealed' system the fluid sure did pick up a lot of dirt.
>
> >> I'll guess the black material was actually in the system to begin with.
> >> Material lost from the hoses and seals. Rubber that has decayed.
>
> > Brake fluid turns DARK brown (nearly black) as it absorbs moisture. I
> > agree a lot of what you see may be rubber and iron oxide caused by the
> > contaminated fluid, but a lot of it is also simply the contaminated fluid.
>
> Although black is different than dark brown. Old, moisture ridden fluid
> I've found is dark brown when taken out and put in a separate container
> as described.
Once more - moisture does NOT turn BF brown. If it did, 25% water in my
BF in the pimento jar would have turned brown by now - 11 months. It
hasn't. It looks like it did the day it came out of the can.
What will turn BF brown is heat. And just because it turns brown,
doesn't necessarily mean it's bad - it takes very little heat to start
it turning brown. If you doubt this, try water, and try heat. I have.
> I've seen fluid that looked blackish through the plastic
> but once drained was just brown. For it to be an opaque black once
> drained and placed in a glass bottle something had to be dissolved in the
> fluid, otherwise it would have still be a brown/rust color.
Heat will also turn it nearly black. Put some in a pot. Heat it. It
instantly starts to change color. Keep heating it, and by the time it
starts to smoke, it will be a very dark reddish brown, and be nearly
opaque.
> Of course that doesn't mean dirt and crap didn't get in the master
> cylinder resovoir. I've seen that.
--
Duncan Wood
Well the moisture meter says it's got in their from somewhere. I'd be
interested to know where from though . (It's got into the brake fluid on my
Triumph, Peugeot Audi, Ford & Rover so far)
bill horne
I do. Neither the service manual for my 83, nor the service manual for
my 96 says anything about opening the bleeder. What both of them say is
to remove 2/3 of the fluid from the MC before compressing the piston. I
don't even do that, because experience has shown me that I don't have to
compress the piston far enough to cause an overflow. No one but myself
has ever touched the brake system on the 83 or the 96 except myself,
both work fine, and have never required maintenance to the hydraulic
system. Never.
Someone, however - perhaps someone such as yourself - apparently touched
the brake systems on every used vehicle I've owned, since everyone of
them eventually required maintenance to some part of the hydraulic
system. Probably some bozo taking the cap off once a month to check the
fluid, and letting in moisture, dirt, and gnats. If I ever buy another
used vehicle, one of the first things I'll do is flush the brake system.
bill horne
>
> Chas Hurst wrote:
>
> >
> > A number of brake MC have a rubber bladder or bellows incorporated to the
> > lid or cap. My ' 68 Olds has one. These systems are sealed. The
> > bladder/bellows expands as the fluid level drops. Have you never seen this?
> >
> > Chas Hurst
> >
> >
>
> Of course. The point is that the system isn't sealed, its simply closed
> to a level reasonable enough to prevent intrusion of dirt and water.
> That thin rubber bellows is *quite* permeable to water vapor,
Is it? On what do you base that? And if it is *quite* permeable, how do
you explain:
The 3 major US manufacturers do not recommend periodic changing of BF.
Ford specifically recommends against it, except for the F53 MH.
Ford also says they "measured the water content in seven- to 10-year-old
Ford vehicles and found that the water content was actually quite low:
only 1 to 1-1/2 percent. So based on their findings and the design
target of three percent water, they see no need to change the fluid for
preventive maintenance.
and:
Barring malfunction, GM says it will last the life of the vehicle.
and:
DaimlerChrysler says it sees "no reason to change the fluid for
preventive maintenance - contrary to most aftermarket recommendations.
> though,
> and the presence of a very hygroscopic fluid on the other side of it
> serves to speed the process. The idea that opening the cap
It is completely unnecessary to open the cap to check the level, so why
open it, and let Anything in there?
> for 10
> seconds to check the fluid will allow massive contamination of the fluid
> is absurd, but the resident troll seems married to that idea.
Mike Romain
>
>
> That thin rubber bellows is *quite* permeable to water vapor, though,
> and the presence of a very hygroscopic fluid on the other side of it
> serves to speed the process.
Just in case no one else has clued you in, you are totally full of shit!
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Brent P
> Brent P wrote:
>>
>> In article <EOGdnZ4oLP2...@texas.net>, Steve wrote:
>> > Brent P wrote:
>> >> In article <uGIra.674988$L1.192520@sccrnsc02>, Clyde Merkswitch wrote:
>>
>> >>>As a precaution, I did a flush on my '96 Ford Escort with 80k miles
>> >>>earlier this year. It was the first time in the life of the car that
>> >>>such a service had been performed. The fluid that came out was opaque
>> >>>BLACK when viewed in a glass Snapple bottle. That's all the proof I need.
>>
>> >>>For a 'sealed' system the fluid sure did pick up a lot of dirt.
>>
>> >> I'll guess the black material was actually in the system to begin with.
>> >> Material lost from the hoses and seals. Rubber that has decayed.
>>
>> > Brake fluid turns DARK brown (nearly black) as it absorbs moisture. I
>> > agree a lot of what you see may be rubber and iron oxide caused by the
>> > contaminated fluid, but a lot of it is also simply the contaminated fluid.
>>
>> Although black is different than dark brown. Old, moisture ridden fluid
>> I've found is dark brown when taken out and put in a separate container
>> as described.
> Once more - moisture does NOT turn BF brown. If it did, 25% water in my
> BF in the pimento jar would have turned brown by now - 11 months. It
> hasn't. It looks like it did the day it came out of the can.
Read again, I said old, moisture ridden fluid ... taken out <of a vehicle>
is dark brown. That doesn't mean moisture turns it brown, just that it's
old nasty used fluid that has moisture in it.
> What will turn BF brown is heat. And just because it turns brown,
> doesn't necessarily mean it's bad - it takes very little heat to start
> it turning brown. If you doubt this, try water, and try heat. I have.
Again you seem to be attributing to me alot that isn't there. Read again.
Particularly the word *OLD*. This means it's fluid that has been in the
system a very long time. Like that in a '82 olds I replaced the master
cylinder on. There was a *LEAF* in the master cylinder a mud-like sludge.
>> I've seen fluid that looked blackish through the plastic
>> but once drained was just brown. For it to be an opaque black once
>> drained and placed in a glass bottle something had to be dissolved in the
>> fluid, otherwise it would have still be a brown/rust color.
> Heat will also turn it nearly black. Put some in a pot. Heat it. It
> instantly starts to change color. Keep heating it, and by the time it
> starts to smoke, it will be a very dark reddish brown, and be nearly
> opaque.
The same will happen to various materials when heated on a stove to a
point of burning, doesn't mean it happens in regular service. If brake
fluid has been heated such that it has turned opaque black and is
actually *burning* in the system there are some serious problems with
the brake system.
bill horne
> I
> will agree opening a M/C for a check "shouldn't" introduce any quantity of
> contamination, but nothing on a car is foolproof.
You are wrong. If you let new, moist air into the MC, the BF will almost
immediately suck up the moisture. "Check" it enough times, and you'll
get significant moisture in the fluid. Periodically changing the air in
the MC is a bad idea.
If I breathe on BF in a powder scale pan, the weight has increased by
the time the scale settles down. And then, if I watch it for 15-20
seconds, the weight decreases. BF breathes water, and it breathes it
damned fast.
Unless the maker of your particular vehicle says to open the MC or
change the fluid, leave the damned thing alone, and you're unlikely to
have problems resulting from contaminated BF.
Thomas Tornblom
has been changed regularly.
The clutch masters reservoir was not clear OTOH and I doubt that it
had ever been changed before I got the car.
Thomas
Ilene...@lmailcity.com
will continue to debate the need for changing brake fluid. The
amount of moisture may be small, but it is a known fact the
moisture WILL enter the system over time. It is not the amount
that is important, it is detrimental effect of that small amount
of water in the bottom of the system over time, that is the
problem. People spend extra money to regularly change their
engine oil long before it needs to be changed because of what
they believe are the consequences of not doing so. Why NOT then
spend a few dollars to change the fluid every couple of years,
since it will benefit the system? Any automobile collector will
tell you they use DOT 5 fluid to avoid the numerous problems
attributed to that small amount of moisture over time.
mike hunt
nut
bill horne
> As for the recent post that quoted Ford as saying you shouldn't worry
> about re-compressing calipers without opening the bleeder, thats fine
> for Ford. I have a 1993 Chrysler factory service manual that explicitly
> warns NOT to re-compress calipers without opening the bleeder because of
> the risk of forcing contaminated fluid back into the ABS mechanism.
Then do as I have repeatedly suggested - do what the manual for your
specific vehicle says do - but I have no intention of using a 93
Chrysler manual to work on my 83 and 96 Chevys. And your Chrysler manual
is not the gospel for all the other vehicles out there.
bill horne
Then shine a flashlight on the other side - or the end - of the MC
reservoir. That works even on water. It'll certainly work on BF. There
is absolutely no need to open the cap to check the fluid level in MCs
that are designed for fluid level checking without removing the cap.