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Copper brake lines
Canada EH! - 16/10/08 at 07:05 PM

There seems to be many posts regarding copper brake lines. In the 50 yrs I have been messing with cars, North American, and British as well as Japanese, I have never seen copper brake lines. We use aluminum lines on aircraft and Can-Am cars. I was thinking of using aluminum on my Locost, also they match up well with -size aircraft hardware. Is this a UK thing?

minitici - 16/10/08 at 07:18 PM

Most often we use "Kunifer" which is a copper-nickel alloy.
This is not prone to work/stress hardening unlike pure copper.

DIY Si - 16/10/08 at 07:41 PM

As said above, it's not actually copper, merely copper coloured. Helps differentiate from the more normal "steel" lines on tin tops. IIRC they're not actually steel either, but you get the idea.

David Jenkins - 16/10/08 at 08:09 PM

quote:
Originally posted by minitici
Most often we use "Kunifer" which is a copper-nickel alloy.


To be precise, copper (Cu), nickel (Ni) and Iron (Fe) = CuNiFe, a.k.a. Kunifer.

As used by Volvo (or used to be, anyway)

[Edited on 16/10/08 by David Jenkins]

hillbillyracer - 16/10/08 at 08:09 PM

It's the norm to use copper here when making replacemnt brake pipes. The most important thing I've found when using it is to put something like copper anti-seize compound on the pipe under the tube nut so the nut doesnt get seized to the pipe. I've often gone to replace the component to which the copper pipe was fitted mabye a year or so later & the tube nut is seized to the pipe & it often twists the end of the pipe off so you need to make another new pipe even though it was OK before you started the job.

rusty nuts - 16/10/08 at 08:33 PM

quote:
Originally posted by hillbillyracer
It's the norm to use copper here when making replacemnt brake pipes. The most important thing I've found when using it is to put something like copper anti-seize compound on the pipe under the tube nut so the nut doesnt get seized to the pipe. I've often gone to replace the component to which the copper pipe was fitted mabye a year or so later & the tube nut is seized to the pipe & it often twists the end of the pipe off so you need to make another new pipe even though it was OK before you started the job.



If people used the correct brass nuts they wouldn't sieze

JAG - 17/10/08 at 07:25 AM

There are several reasons why car manufacturers stick with steel pipes. The use of

quote:

copper anti-seize compound

on steel nuts on copper pipes is one reason.

This anti-sieze compound is a mineral oil based product and using it in reasonable proximity to a vegetable oil based braking system is a risk that car and braking system manufacturers WON'T take.

The mineral oil in the anti-sieze compound can mix with the brake fluid (if any gets into the joint) and attack all the rubber seals in the braking system. Concentrations of less than 1% can do enough damage to stop the system working. It may seem like a remote risk but car and brake system makers won't take the chance.

There's also the much higher burst pressure of steel pipes in their favour.

DarrenW - 17/10/08 at 03:49 PM

i wouldnt be surprised if OE's use steel cos its cheaper or lends itself better to being formed to exact shapes on CNC tube benders.