STAINLESS STEEL BRAIDED BRAKE PIPES

Technical queries or suggestions
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jack bellinger
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STAINLESS STEEL BRAIDED BRAKE PIPES

Post by jack bellinger »

Just thought you lot might be interested..
luckily for me This happened on John and Mary,s drive
just as I was about to Drive off .
On my +8 I run Stainless Braided Hoses this hose was on the back where the hose goes from the Chassis to the Tee Piece on the Axle
The Axle obviously goes up and down a fair amount and the pipe fractured just where the pipe enters the Tee Piece !!
To look at the pipe from the outside it had no defect the only sign was that you could see the fluid seep out of the Braid but when the braid was removed you can see where the split is..
Result was total Brake Failure (pedal to the floor)

I dont want to Scare anyone but these have been on my car since 1992 (and still look perfect) and have probably done a fair bit of work But it shows that everything no matter how good it is has a LIFE mine lasted 15 years Too long I think!!

You cannot see the damage without taking the pipe to bits .. then its ruined anyway

How many times has the axle moved up and down to cause this (Who Knows)
Just Dont Leave Too Long unless you like to give your buttocks a good Work Out

love jack
Ps thanks for the help in the Rain John and Mary
----- Image
Barry Sumner
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Post by Barry Sumner »

I had a similar failure on NYF when Keith Morris and I did the Monte Carlo back in 1991, 250 miles on the handbrake before we could carry out a repair.

Jack is right they do have “life” for SS covered PTFE hose was developed for the aircraft industry, I think, and they life everything!

However looking at the NYF failure, I came to the conclusion that the failure was probably down to the hose being too short (i.e. made up to same length as standard hose) rubber is more forgiving than PTFE hose – and with the weight we had, making the axle go up and down to its max travel.
So apart from changing it I have made the hose longer and in doing so - creating a lazy S – which reduces the flex and stress on where the hose joins the union, creating the failure shown in Jacks picture – Good picture Jack!!

Barry
Ps I do recall seeing the failure of a conventional rubber hose, in the same position i.e. hose to union area, which gives weight to the “to short” theory. – applies to front as well as rear hoses.
So if in doubt – change them!!
Lorne Goldman
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Re: STAINLESS STEEL BRAIDED BRAKE PIPES

Post by Lorne Goldman »

Good heads-up Jack! One can never be too careful with brake lines and their fittings.

That being said the piece you posted looks like it was homemade..from from braided nitrile rubber rather than Aeroquip teflon (which is a considerably safer bet.) The fittings are not something I have seen on brake lines, and only occasionally on fuel lines where one must switch from AN fittings the clampable fittings for some (bad) reason.

Two other possible anomalies. 1.) The t-piece looks like mild steel and 2) I can see no evidence of an olive on the hose, which would have made that type of split unlikely. Was this item clamped with simply a threaded cover to hide the end?

I think you are right. The characteristics of this specific hose, coupled with a too short length..resulted in the split. It is surprising it lasted that long. I am happy you are safe.

Lorne
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jack bellinger
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Post by jack bellinger »

The hose is teflon. I removed the briad/olive/nut and opened the split and just pushed the Brake pipe end in for the picture.so its looks a bit more Dramatic..
1. The Brake pedal went straight to the floor
2. When the complete hose was looked at you cannot see under the braid but hose looked Good

love jack
Jim Mountain
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Post by Jim Mountain »

Found this on the "think Automotive" catalogue :-

Aeroquip TFE Racing Hose/Aeroquip 666 Aerospace hose/Moquip TFE hose

"Due to its very low ratio of expansion to pressure, this hose has
proved to be ideal for use on flexible lines in competition vehicle
braking and clutch systems providing a desirable “hard” pedal with
re duced travel. It does not con form to existing standards laid down
for normal road vehicles, if subjected to continuous flexing the
stainless steel strands will eventually fracture and could penetrate
the Teflon liner, how ever this eventuality does not occur within the
normal life of a competition vehicle, this hose in common with all
other components used on such vehicles should be regularly in -
spected for signs of wear."

http://www.thinkauto.com
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