Splice brake lines?
Keith Cavis
I need to replace a section of rusted brake line. The replacement lines I've
seen at parts stores have flare fittings on both ends. Since I can't get the
end of the old one loose from the junction block, and since only a small part
is rusted, I'd like to splice in a section where one end is just a plain cut
without a flare (I'm assuming the flare tools I have for copper pipe aren't
going to work for this). Is there a safe way to do this, using rubber hose
that's brake-fluid resistant, then clamping the ends? Or will the high
pressure blow this hose up, or make for a mushy pedal?
Thanks
KC
Chuck Lampman
In article <4phpuj$4...@magpie.cdev.com>, Ca...@cdev.com (Keith Cavis) wrote:
> <snip> I'd like to splice in a section where one end is just a plain cut
> without a flare
Bad idea!
>(I'm assuming the flare tools I have for copper pipe aren't
> going to work for this).
Safe assumption- brake lines use a double flare, made by a special tool.
Single flares don't work with brakes.
>Is there a safe way to do this, using rubber hose
> that's brake-fluid resistant, then clamping the ends?
Don't even think about it!
>Or will the high
> pressure blow this hose up,
Yes, instantly.
It might be possible to double flare your tubing in place (don't forget to
slip a nut on first) but chances are excellent that you won't get a good
flare, working in a tight spot under the car. It takes a good deal of
experience or luck to get a good double flare on the benchtop, let alone
under the car!
Keith, since the possible consequences of failure include death (both
yours, and the guy coming the other way!) do yourself a favor and fix it
right. Get the old nut out of the junction block and replace the entire
line with new from the parts house, with factory-made flares. If you can't
get the nut out, replace the junction block.
Chuck Lampman
chuck....@tuff.gatech.edu
rob -TTA-
chuck....@tuff.gatech.edu (Chuck Lampman) wrote:
>In article <4phpuj$4...@magpie.cdev.com>, Ca...@cdev.com (Keith Cavis) wrote:
>> <snip> I'd like to splice in a section where one end is just a plain cut
>> without a flare
>Bad idea!
ditto that
>>(I'm assuming the flare tools I have for copper pipe aren't
>> going to work for this).
>Safe assumption- brake lines use a double flare, made by a special tool.
>Single flares don't work with brakes.
I did that to the trans cooler lines and it barely works there with
about 60psi in those lines. I flared the lines and used hose wich
fitted about an 1.5" over the line with two clamps on each side. This
will only last a while.
JBlessing
In article <4phpuj$4...@magpie.cdev.com>, Ca...@cdev.com says...
>
>I need to replace a section of rusted brake line. The replacement lines
I'
>ve
>seen at parts stores have flare fittings on both ends. Since I can't get
t
>he
>end of the old one loose from the junction block, and since only a small
pa
>rt
cu
>t
>without a flare (I'm assuming the flare tools I have for copper pipe
aren't
>
>going to work for this). Is there a safe way to do this, using rubber
hose
>
>pressure blow this hose up, or make for a mushy pedal?
>
>Thanks
>KC
>
--
Don't even think of it. Get a flaring tool and do it right, or let someone
with the tool do it. Or better yet get the fitting off and replace the
whole line. I haven't seen a fitting yet that I couldn't get off with a
little effort. If you haven't already destroyed the hex on the fitting cut
the brake line off flush at the fitting and use a 6 point socket on it.
Jordan Blessing L1 Master Tech
Martyn Uttley
Ca...@cdev.com (Keith Cavis) wrote:
>I need to replace a section of rusted brake line. The replacement lines I've
>seen at parts stores have flare fittings on both ends. Since I can't get the
>end of the old one loose from the junction block, and since only a small part
>is rusted, I'd like to splice in a section where one end is just a plain cut
>without a flare (I'm assuming the flare tools I have for copper pipe aren't
>going to work for this). Is there a safe way to do this, using rubber hose
>that's brake-fluid resistant, then clamping the ends? Or will the high
>pressure blow this hose up, or make for a mushy pedal?
KC
First, a repair like you have mentioned would be extremely dangerous. In
my part of the world it might also be illegal. Solid pipe with suitable
hydraulic connections might be possible but if the pipe is corroding I
would strongly recommend complete replacement.
Your proposed repair would almost certainly leak.
!!!!!
(O O)
+-----------------oOO------(_)-------------------------+
! Martyn C. Uttley Hong Kong !
! Fax (852) 2873 3342 e-mail mut...@hk.super.net !
+-----------------------------------oOO----------------+
|__|__|
|| ||
ooO Ooo
Rick Prather
Ca...@cdev.com (Keith Cavis) wrote:
>I need to replace a section of rusted brake line. The replacement lines I've
>seen at parts stores have flare fittings on both ends. Since I can't get the
>end of the old one loose from the junction block, and since only a small part
>is rusted, I'd like to splice in a section where one end is just a plain cut
>without a flare (I'm assuming the flare tools I have for copper pipe aren't
>going to work for this). Is there a safe way to do this, using rubber hose
>that's brake-fluid resistant, then clamping the ends? Or will the high
>pressure blow this hose up, or make for a mushy pedal?
>
>Thanks
>KC
>
Don't even think about putting in a rubber hose section unless you get
a pre-made piece of brake hose with fittings. Then you will have to
double flare the new ends of your line. You could also do this with a
piece of pre-made steel line with fittings, but again, only if you
have a double-flare tool.
Rick
Andy Dingley
The moving finger of Ca...@cdev.com (Keith Cavis) having written:
>I need to replace a section of rusted brake line.
You might like to replace all of them together. It's mittle extra work
while you're underneath, the others are of similar age anyway, and it
means that awkward unions that won't come apart may be dealt with on
the bench, in comfort.
Splicing is safe, but only if you make a proper joint with flared
connections. Annealed copper alloy pipe can be flared in situ, but
steel pipe needs more force and so must be clamped in a vice. I often
flare copper in situ, because I can thread and fit the pipe into place
more easily and then only have to cut it to length when I have an
exact idea how long it should be. It gives a neater job, and it's
often easier.
As far as the pipe between splices goes, it's your choice as to
whether to use rigid or flexible. Remember though that flexible brake
hoses must either be rubber with hydraulically crimped fitings (and
you're not going to assemble those at home) or something like Aeroquip
2807, which is expensive.
Rubber or plastic pipe, slipped over the cut ends of the pipe and
secured by jubilee clips is NOT acceptable, even though I've seen it
done a few times.
At least you're in America. DIN flares, as used in Europe, are much
harder to make well in situ.
Andy Dingley
The moving finger of rwar...@sigg.com (rob -TTA-) having written:
>>Safe assumption- brake lines use a double flare, made by a special tool.
>>Single flares don't work with brakes.
>
>I did that to the trans cooler lines and it barely works there with
>about 60psi in those lines. I flared the lines and used hose wich
>fitted about an 1.5" over the line with two clamps on each side. This
>will only last a while.
That's not a "flare" in the sense we're talking about for brakes. Your
flare was to make a raised barb in a standpipe or spigot to fit inside
a flexible hose. You apply a circumferential compression by a jubilee
clip, and this deforms the flexible hose radially. If you're trying to
stop the hose pullling off, put the clip behind the barb. If you're
trying to stop it leaking, put it _over_ the barb. A fitting like this
should be perfectly adequate for transmission or oil plumbing. If it
isn't your either putting the clips on wrong or something is the wrong
size.
A "flare" in brake plumbing terms is when the rigid pipe is formed
into some form of cone. This allows an axial force from the tube nut
being tightened to compress a metal-to-metal contact between the pipe
and the coned surface inside the fitting.
Rick Prather
Ca...@cdev.com (Keith Cavis) wrote:
>I need to replace a section of rusted brake line. The replacement lines I've
>seen at parts stores have flare fittings on both ends. Since I can't get the
>end of the old one loose from the junction block, and since only a small part
>is rusted, I'd like to splice in a section where one end is just a plain cut
>without a flare (I'm assuming the flare tools I have for copper pipe aren't
>going to work for this). Is there a safe way to do this, using rubber hose
>that's brake-fluid resistant, then clamping the ends? Or will the high
>pressure blow this hose up, or make for a mushy pedal?
>
>Thanks
>KC
>
Don't even think about putting in a piece of rubber hose.
The only way I can see you repairing your line would be if you could
find a pre-made piece of brake pipe (or, I guess, rubber brake line)
with fittings and you did a double flare on each new end of your cut
line.
Rick