Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
compression fittings on brake lines
1,790 views
Skip to first unread message
Nate Nagel
Apr 12, 2013, 2:30:30 PM4/12/13
to
Does anyone have a link to any law or standard that allows or prohibits
their use?
Was having a discussion with a mechanic yesterday and the wrench was
saying that it was easier to use a compression fitting than double
flaring and he didn't have a problem using them; my position was that if
I needed to replace a hard line where it was easier to cut and splice in
the middle than rerun the whole thing that I would always use a double
flare and a union, because of the impossibility of the fitting blowing
apart under pressure save for a failure of the tubing itself. the
discussion was prompted because he was looking at a repair I'd done on a
friend's vehicle when the rear brakes had failed; the hose to the rear
axle had failed and replacement required replacement of both the axle
lines and the back half of the rear body line due to rust, and he'd
noticed that the one splice that I'd done was a double flare union.
However when I went to research the issue I see a lot of opinions that
"it's illegal" to use compression fittings but no links to actual
references nor could I find anything in the pertinent safety inspection
standards (NB: I'm not a vehicle inspector nor have I ever been, so I
don't know if there is an "unwritten rule" that compression fittings =
failure.) If anyone has any knowledge of this issue I'd appreciate your
input esp. if it is specific to VA, MD, or DC.
I also certainly hope that the mechanic was referring to a good steel
Swagelok fitting (which is at least rated for the pressures used in an
automotive brake application) and not the brass ones like you'd use to
hook up an icemaker!
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
their use?
Was having a discussion with a mechanic yesterday and the wrench was
saying that it was easier to use a compression fitting than double
flaring and he didn't have a problem using them; my position was that if
I needed to replace a hard line where it was easier to cut and splice in
the middle than rerun the whole thing that I would always use a double
flare and a union, because of the impossibility of the fitting blowing
apart under pressure save for a failure of the tubing itself. the
discussion was prompted because he was looking at a repair I'd done on a
friend's vehicle when the rear brakes had failed; the hose to the rear
axle had failed and replacement required replacement of both the axle
lines and the back half of the rear body line due to rust, and he'd
noticed that the one splice that I'd done was a double flare union.
However when I went to research the issue I see a lot of opinions that
"it's illegal" to use compression fittings but no links to actual
references nor could I find anything in the pertinent safety inspection
standards (NB: I'm not a vehicle inspector nor have I ever been, so I
don't know if there is an "unwritten rule" that compression fittings =
failure.) If anyone has any knowledge of this issue I'd appreciate your
input esp. if it is specific to VA, MD, or DC.
I also certainly hope that the mechanic was referring to a good steel
Swagelok fitting (which is at least rated for the pressures used in an
automotive brake application) and not the brass ones like you'd use to
hook up an icemaker!
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
m6onz5a
Apr 12, 2013, 2:50:08 PM4/12/13
to
inspections. But I also have customers that use them too. As far as I
know they haven't had any issues with them. I know I wouldn't want
them on my car. I'll only use unions, or replace the whole line.
Chas
Nate Nagel
Apr 12, 2013, 2:59:37 PM4/12/13
to
http://www.ehow.com/how_5499634_splice-auto-steel-brake-lines.html
Sadly, ehow doesn't seem to have a "-1" button. I'm guessing most
intelligent people take anything posted there with a shaker of salt
anyway, but really, this is astonishingly irresponsible.
Nate Nagel
Apr 12, 2013, 3:03:02 PM4/12/13
to
compression fittings should fail a safety inspection? This is actually
pertinent as the guy to whom I was talking is in MD but not an inspector
and I'm sure he'd appreciate a correction if it saves him from potential
future liability down the road.
Geoff Welsh
Apr 12, 2013, 3:58:35 PM4/12/13
to
Nate Nagel wrote:
> Does anyone have a link to any law or standard that allows or prohibits
> their use?
>
will you settle for proof (almost) by contradiction?;
> Does anyone have a link to any law or standard that allows or prohibits
> their use?
>
http://standards.sae.org/j2879_201107/
indicates that SAE spec J2879 "applies to 90 degree double inverted
flares used on common sizes of automotive hydraulic brake tubes, and
their associated tube nuts and mating ports"
every test I've ever taken, had as the correct answer for brake line
repair, "use a double flare".
and that's enough for me,
GW
AMuzi
Apr 12, 2013, 5:21:38 PM4/12/13
to
A quick web search shows this discussion in multiple venues
with several comments such as 'will probably be OK' without
direct experience and also 'will fail inspection' but no
statute cited. Of course it may be an administrative policy
rather than a statute. Or not.
Frankly I don't see any problem with a normal flared line
which logically seems matched to a 'high stakes risk when it
breaks' application. Flares and flaring tools are cheap,
well supported, ubiquitous and not complex.
If any of my cars had dual-diagonal braking systems and if I
were away from civilization (new brake line and/or a flaring
tool), I _might_ think about a compression fitting. But they
don't and so I don't.
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
Nate Nagel
Apr 12, 2013, 6:02:31 PM4/12/13
to
position but I can't find any official backup to it (at least in MD or
VA; I have found explicit references for other farther away states)
therefore I'll never change the guy's mind as to what is and isn't a
proper repair as I don't really have any backup.
For my own part I will continue to flare...
BTW is it just me or has steel tubing gotten softer over the years? I
had to do three different flares to make the repair, one under the
vehicle (which always scares me, I prefer working on the bench) and they
weren't nearly as much of a PITA as I remembered. I did deburr the
lines and dress with a file before attempting to flare but I was doing
that before as well. Been years since I've had to break out the flaring
tool and I can't say that I really miss it, but it is awful handy to
have (and it just looks more professional when your lines are the exact
right length rather than having loops in them...)
Steve W.
Apr 12, 2013, 7:41:33 PM4/12/13
to
Procedures: Reject Vehicle If:
(a) Hydraulic System�Visually inspect condition of hydraulic system.
(i) Inspect wheel cylinders for leakage and operation. Do not
remove dust covers.
(ii) Inspect hydraulic hoses and brake lines for leaks, cracks,
chafing, flattened or restricted sections, improper support, rusting
causing pitting, and improper material.
(iii) Inspect master cylinder for leakage and fluid level of all
sections. (Be sure no dirt gets into reservoir when cover is removed and
that the gasket is serviceable.)
(a)
(i) Wheel cylinder leaks or fails to operate.
(ii) Hoses, or brake lines are cracked, chafed, flattened,
restricted, or are rusted and pitting is visible, are improperly
supported, or lines have been repaired or replaced with copper tubing or
other material not designed for hydraulic brake lines. Hoses or brake
lines are mounted to contact wheels or body during steering or
suspension movement.
(iii) Master cylinder leaks.
(iv) The fluid level in any section is less than 1/2 full.
(v) The gasket does not properly seal master cylinder.
Compression fittings fall under the "material not designed for hydraulic
brake lines"
Connecticut:
BRAKE LINES - Tubing must be steel and properly attached and supported
(at least every 18")
and hoses shall not be kinked, twisted, or frayed. Hoses must not be
under tension during full right
and full left-hand turn, or during full compression or full extension of
suspension. Automotive
stainless steel tubing and braided hoses are acceptable but compression
fitting will not be allowed.
In NY they are specifically called out as an automatic fail if used on
any part of the brake system as well.
--
Steve W.
Steve W.
Apr 12, 2013, 7:48:46 PM4/12/13
to
other than something general like "the brakes must stop the vehicle"
REALLY??
I know a few states specifically call attention to compression fittings
being bad juju.
Personally by the time you get the correct compression fitting size, get
the line clean enough to seal and cut correctly, it it faster and easier
to spool out some line and flare it.
I keep a good supply of line in steel, stainless and cunifer on hand.
plus all the fittings and about 4 different flare tools.
--
Steve W.
Brent
Apr 12, 2013, 8:05:53 PM4/12/13
to
On 2013-04-12, AMuzi <a...@yellowjersey.org> wrote:
> A quick web search shows this discussion in multiple venues
> with several comments such as 'will probably be OK' without
> direct experience and also 'will fail inspection' but no
> statute cited. Of course it may be an administrative policy
> rather than a statute. Or not.
>
> Frankly I don't see any problem with a normal flared line
> which logically seems matched to a 'high stakes risk when it
> breaks' application. Flares and flaring tools are cheap,
> well supported, ubiquitous and not complex.
Some folks even argue that adding the additional flare fittings
> A quick web search shows this discussion in multiple venues
> with several comments such as 'will probably be OK' without
> direct experience and also 'will fail inspection' but no
> statute cited. Of course it may be an administrative policy
> rather than a statute. Or not.
>
> Frankly I don't see any problem with a normal flared line
> which logically seems matched to a 'high stakes risk when it
> breaks' application. Flares and flaring tools are cheap,
> well supported, ubiquitous and not complex.
in the line is too dangerous. I disagreed with this as I have
found that flare fittings once they aren't leaking they'll never
leak until someone attempts to take them apart and the line breaks
because the fittings are rusted together.
> If any of my cars had dual-diagonal braking systems and if I
> were away from civilization (new brake line and/or a flaring
> tool), I _might_ think about a compression fitting. But they
> don't and so I don't.
conditions. If I had no flare tool and all I could get a hold of was
plumbing materials... ok... that's desparation mode to hobble carefully
home or to the nearest place where the proper materials could be
purchased. For an actual long-term repair? no.
m6onz5a
Apr 13, 2013, 10:34:45 AM4/13/13
to
Nate Nagel
Apr 13, 2013, 10:35:55 AM4/13/13
to
On 04/12/2013 07:48 PM, Steve W. wrote:
> Geoff Welsh wrote:
>> Nate Nagel wrote:
>>> Does anyone have a link to any law or standard that allows or prohibits
>>> their use?
>>>
>>
>> will you settle for proof (almost) by contradiction?;
>>
>> http://standards.sae.org/j2879_201107/
>>
>> indicates that SAE spec J2879 "applies to 90 degree double inverted
>> flares used on common sizes of automotive hydraulic brake tubes, and
>> their associated tube nuts and mating ports"
>>
>> every test I've ever taken, had as the correct answer for brake line
>> repair, "use a double flare".
>>
>> and that's enough for me,
>> GW
>
>
> The problem is that some states don't have anything in the requirements
> other than something general like "the brakes must stop the vehicle"
> REALLY??
>
> I know a few states specifically call attention to compression fittings
> being bad juju.
Understood, but it doesn't seem like MD or VA explicitly do so...
> Geoff Welsh wrote:
>> Nate Nagel wrote:
>>> Does anyone have a link to any law or standard that allows or prohibits
>>> their use?
>>>
>>
>> will you settle for proof (almost) by contradiction?;
>>
>> http://standards.sae.org/j2879_201107/
>>
>> indicates that SAE spec J2879 "applies to 90 degree double inverted
>> flares used on common sizes of automotive hydraulic brake tubes, and
>> their associated tube nuts and mating ports"
>>
>> every test I've ever taken, had as the correct answer for brake line
>> repair, "use a double flare".
>>
>> and that's enough for me,
>> GW
>
>
> The problem is that some states don't have anything in the requirements
> other than something general like "the brakes must stop the vehicle"
> REALLY??
>
> I know a few states specifically call attention to compression fittings
> being bad juju.
>
> Personally by the time you get the correct compression fitting size, get
> the line clean enough to seal and cut correctly, it it faster and easier
> to spool out some line and flare it.
> I keep a good supply of line in steel, stainless and cunifer on hand.
> plus all the fittings and about 4 different flare tools.
would love to be able to fab my own stainless lines but the instructions
for my best flaring tool (K-D I think?) explicitly state that it's not
for use on stainless, presumably because it's harder than the mild steel
that seems to be the standard.
Thread drift 2: while at the parts store buying fittings for my friend's
repair, the sales guy showed me some of the new copper-nickel tubing, so
it's apparently on sale here now. Has anyone had any experience with
safety inspections on a car that has had this tubing used? We didn't
use it because his pickup is 20 years old and the tubing was very
expensive, but if I end up having to replace a line on a car I plan on
keeping a long time, this might be a good option.
Nate Nagel
Apr 13, 2013, 10:41:10 AM4/13/13
to
discretion" thing so lacking a friend who's a certified inspector I
still don't really have any backup for my position...
> Connecticut:
>
> BRAKE LINES - Tubing must be steel and properly attached and supported
> (at least every 18")
> and hoses shall not be kinked, twisted, or frayed. Hoses must not be
> under tension during full right
> and full left-hand turn, or during full compression or full extension of
> suspension. Automotive
> stainless steel tubing and braided hoses are acceptable but compression
> fitting will not be allowed.
prohibit the new copper-nickel stuff which sounds like a bad idea on the
face of it but apparently does not have the work-hardening
characteristics that one would expect from a copper alloy, and the
thought of being able to use a nice soft metal that doesn't rust is very
appealing.
m6onz5a
Apr 13, 2013, 11:03:38 AM4/13/13
to
> BTW is it just me or has steel tubing gotten softer over the years? I
> had to do three different flares to make the repair, one under the
> vehicle (which always scares me, I prefer working on the bench) and they
> weren't nearly as much of a PITA as I remembered. I did deburr the
> lines and dress with a file before attempting to flare but I was doing
> that before as well. Been years since I've had to break out the flaring
> tool and I can't say that I really miss it, but it is awful handy to
> have (and it just looks more professional when your lines are the exact
> right length rather than having loops in them...)
>
> nate
>
> --
> replace "roosters" with "cox" to reply.http://members.cox.net/njnagel
yes brake lines seem to be softer now. the 25ft roll we sell is much
> had to do three different flares to make the repair, one under the
> vehicle (which always scares me, I prefer working on the bench) and they
> weren't nearly as much of a PITA as I remembered. I did deburr the
> lines and dress with a file before attempting to flare but I was doing
> that before as well. Been years since I've had to break out the flaring
> tool and I can't say that I really miss it, but it is awful handy to
> have (and it just looks more professional when your lines are the exact
> right length rather than having loops in them...)
>
> nate
>
> --
> replace "roosters" with "cox" to reply.http://members.cox.net/njnagel
softer than the straight pieces we sell too
Steve W.
Apr 13, 2013, 12:45:22 PM4/13/13
to
Both make a flare that looks factory with very little effort. The only
bad flare the Sealy did was because the tubing was made wrong.
>
> Thread drift 2: while at the parts store buying fittings for my friend's
> repair, the sales guy showed me some of the new copper-nickel tubing, so
> it's apparently on sale here now. Has anyone had any experience with
> safety inspections on a car that has had this tubing used? We didn't
> use it because his pickup is 20 years old and the tubing was very
> expensive, but if I end up having to replace a line on a car I plan on
> keeping a long time, this might be a good option.
>
> nate
>
nice and doesn't corrode like steel. It's been in use on some imports
for a while. It is MUCH easier to bend and form than steel.
--
Steve W.
Geoff Welsh
Apr 13, 2013, 2:42:59 PM4/13/13
to
Steve W. wrote:
> Nate Nagel wrote:
> Nate Nagel wrote:
>> Thread drift: what flaring tool do you use on 3/16" stainless tubing?
>> I would love to be able to fab my own stainless lines but the
>> instructions for my best flaring tool (K-D I think?) explicitly state
>> that it's not for use on stainless, presumably because it's harder
>> than the mild steel that seems to be the standard.
>
> Mastercool hydraulic for on car stuff,
I drool every time I see that set in a tool catalog, but I know the cost
>> I would love to be able to fab my own stainless lines but the
>> instructions for my best flaring tool (K-D I think?) explicitly state
>> that it's not for use on stainless, presumably because it's harder
>> than the mild steel that seems to be the standard.
>
> Mastercool hydraulic for on car stuff,
to "me using it" ratio is nearly infinite, so I don't have one.
I think Kent-Moore makes/made a nice set too, or maybe it was superseded
by the Mastercool.
GW
Steve W.
Apr 13, 2013, 3:40:14 PM4/13/13
to
about 2 flares and a GM fuel line and it became a "Why in the hell
didn't you buy this before" item.
It is great for making just about any flare needed. If you do one set of
lines for one car it pays for itself in flare quality very fast.
The bench unit is faster in most respects but not good under a vehicle.
--
Steve W.
Ashton Crusher
Apr 13, 2013, 5:52:57 PM4/13/13
to
On Fri, 12 Apr 2013 14:59:37 -0400, Nate Nagel <njn...@roosters.net>
wrote:
Got curious and googled on this subject. Lots of opinions of course.
Looks like there really isn't any reason not to use compression
fittings as far as them coming apart, the only issue seemed to be
leaking if the compression fittings are over-compressed. People don't
like their brake fluid leaking out. And don't use brass on steel
tubing. So when all is said it looks like it can be done safely if
you pay attention to what you are doing but that still doesn't answer
the "is it legal" question. I'd guess the reason it's not legal, if
it fact it's not, is because there is an SAE spec on braking systems
requiring double flare fittings and that the SAE spec is incorporated
by reference into the safety regs.
wrote:
Looks like there really isn't any reason not to use compression
fittings as far as them coming apart, the only issue seemed to be
leaking if the compression fittings are over-compressed. People don't
like their brake fluid leaking out. And don't use brass on steel
tubing. So when all is said it looks like it can be done safely if
you pay attention to what you are doing but that still doesn't answer
the "is it legal" question. I'd guess the reason it's not legal, if
it fact it's not, is because there is an SAE spec on braking systems
requiring double flare fittings and that the SAE spec is incorporated
by reference into the safety regs.
Ashton Crusher
Apr 13, 2013, 6:01:33 PM4/13/13
to
On Fri, 12 Apr 2013 19:41:33 -0400, "Steve W." <csr...@NOTyahoo.com>
wrote:
> (a) Hydraulic System�Visually inspect condition of hydraulic system.
Full employment acts for shops and bureaucrats. A sad byproduct of
nanny states.
wrote:
nanny states.
jim beam
Apr 13, 2013, 6:36:46 PM4/13/13
to
compression junction. compression may work ok most of the time, but it
relies on surface finish quality which is not controlled and therefore
the failure rate is higher.
--
fact check required
jim beam
Apr 13, 2013, 6:37:11 PM4/13/13
to
On 04/12/2013 11:59 AM, Nate Nagel anosognosically driveled:
> Proof that anyone can spew advice on the interwebs
eh? why does the needle on my irony meter seem to be all bent up like a
watch spring???
oh, it's nate spewing "advice" on the interwebs.
--
fact check required
> Proof that anyone can spew advice on the interwebs
watch spring???
oh, it's nate spewing "advice" on the interwebs.
--
fact check required
Nate Nagel
Apr 13, 2013, 7:45:14 PM4/13/13
to
flares but ISO "bubble" flares as I discovered to my chagrin when I had
to replace the first brake line on my first GTI :( And it took me quite
a while to find an inexpensive ISO flare tool, but this was back when
the interwebs weren't as developed as they are today.
Nate Nagel
Apr 13, 2013, 7:46:46 PM4/13/13
to
there is brutal; I failed once for a windshield that was "too
sandblasted" I shit you not and had a friend have to replace her exhaust
system because the inspector told her that he wouldn't pass it if an
exhaust shop welded a dime-sized patch over a hole in her muffler. I'm
all for safe and reliable, but that's just ludicrous.
Nate Nagel
Apr 13, 2013, 7:47:22 PM4/13/13
to
until you shat on the carpet.
m6onz5a
Apr 15, 2013, 11:16:16 AM4/15/13
to
failed my windshield on an old car I used to own for the same reason
( it did need to be replaced). Headlights & ball joints always seem
to fail too even when the ball joints are new.
As for the exhaust they probably figured since someone welded over a
rust hole that the muffler was probably full of rust. Plus that hole
can easily open back up. Not all that ludicrous.
Nate Nagel
Apr 15, 2013, 12:43:15 PM4/15/13
to
a factory stainless system in excellent shape, it looked like one of the
drain holes in the bottom of the muffler just opened up a little bit
through corrosion. The car wasn't even noticeably louder than stock and
there weren't any leaks/holes anywhere in the exhaust other than that
one little hole in the muffler. The system could have lasted another 10
years or so with a proper repair, but the guy was a total jerk to her
and told her that she had to come back to him for reinspection by law (I
believe that to be true) and that he would fail her unless the entire
exhaust system was replaced (it was a welded assembly from the cat back,
and he insisted that no component replacements were acceptable.) Even
if welding the muffler were unacceptable I do not see why the muffler
alone could not have been replaced and the midpipe reused - like I said,
IMHO they are over the top ludicrous and cause people to spend money
that they don't have to. He also failed her for a crack in the
windshield that was at the upper left corner; technically illegal but
couldn't even be seen from the inside of the car. She ended up spending
about the value of the car just to import it into MD for those two items
alone; the car itself was in good shape as I had gone through the
suspension and brakes and replaced her clutch hydraulics for her and
hadn't noticed anything amiss either by inspection or from test driving
the car.
The car that I took through and failed for the windshield should have
failed - but for a failed brake proportioning valve that I deliberately
did not repair to give the inspector something to catch that I was going
to repair anyway. He missed that but nailed me on the windshield which
was in fine shape. However I didn't fight him as it needed to come out
anyway as it was glued in but leaking around the edges so I just had it
replaced instead of reusing the old one.
My impression of the MD safety inspection is that it must have been
enacted through heavy lobbying by car dealers to make private party car
sales damn near impossible.
Steve W.
Apr 15, 2013, 1:05:52 PM4/15/13
to
--
Steve W.
m6onz5a
Apr 15, 2013, 4:00:58 PM4/15/13
to
(brakes, tires wipers, exhaust etc)
as for the drain hole having a little corrosion that is all he needed
to see. I still don't know why just the muffler couldn't be replaced?
If he had issues in the past letting vehicles slide through he could
have been extra thorough. Who knows.
RedRooster
Feb 10, 2018, 7:18:04 PM2/10/18
to
replying to Nate Nagel, RedRooster wrote:
Hey Nate just to let you know... http://mdrules.elaws.us/comar/11.14.09.05
--
for full context, visit https://www.motorsforum.com/tech/compression-fittings-on-brake-lines-110119-.htm
Hey Nate just to let you know... http://mdrules.elaws.us/comar/11.14.09.05
--
for full context, visit https://www.motorsforum.com/tech/compression-fittings-on-brake-lines-110119-.htm
0 new messages