> I'm interested in your collective wisdom and thoughts about
> using copper tubing for brake lines in automobiles.
Very first question : What kind of copper ?
Soft 'refrigeration' copper tubing is not suitable, it will work harden
under repeated pressure cycles and vibration and eventually crack. It's
also not rated for the sort of pressures one can find in a braking system,
especially during a panic stop. And a panic stop is a hell of a time to
find out your brake lines are inadequate !
However, there is a copper alloy used in Europe for brake lines, called
Cunifer, that apparently does not suffer from these problems. It is a bit
softer than the proper Bundy (tin-plated steel) tubing that is normally used
for brakes, which makes it easier to install; and the copper and nickel
content make it very resistant to rust. It's apparently perfectly safe, but
it's not DOT approved.
Some LBC vendors do sell this stuff in the US. I think legally they're
required to tell you that it's not DOT approved, but perhaps I'm mistaken as
they don't seem to do so.
> I met a fellow car club member Tuesday night who extolled
> the virtues of using copper brake lines on his restored
> british cars primarily because it eliminates corrosion
> problems.
Thing is, the British skimped on the tin plating to begin with, and it still
lasted 40 years or more in spite of these cars being driven in all sorts of
conditions. Modern tubing is higher quality and so will probably last even
longer; not to mention the fact that very few people drive their restored
British car through snow, sand and salt on the road.
> He said the biggest caution is to avoid running
> lines where they could be easily damaged, as from a rock,
> since the line would likely rupture. He said there was no
> problem in holding enough pressure.
Ask him how many times he has "locked them up" on his restored British car
... the system pressure depends entirely on how hard you mash the pedal.
1000 psi is entirely possible.
> Also, I was under the impression that copper lines
> were not legal to use according to most DMVs.
It's actually a federal requirement in the USA. The only question is
whether anyone will notice.
I wonder what your insurance company will think if you're ever in an
accident because of illegal brake lines ...
Randall
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