
Originally Posted by
chazza
I disagree with two of your points on copper brake pipe:
1. Diana didn't mention copper alloy, she correctly posted that copper brake pipe is heavy-walled.
2. Copper is no easier than steel to work-harden, especially when it has been annealed after bending and flaring. For that reason I submit that it is no worse than bundy tube when used on a vehicle.
3. Copper brake pipe is legal in WA but I believe not so in Vic.
I have used it on my cars for years but lately it seems to be impossible to buy it,
Cheers Charlie
I know Diana did not specify copper alloy but I believe that this "approved" pipe is designed to be resistant to work hardening.
Copper most definitely work hardens a lot more readily than does steel (although bear in mind this depends on the grade of steel, but this is the case for the sort of tubing that you would consider using - it has to be malleable enough to flare). Annealing it after bending and flaring simply brings it back to where it was before you did that. Further working will still harden it, and the problem is that vibration will do this - just takes longer if you have removed the hardening you put there in working the pipe.
And I would agree that copper is, at least in most cases, no worse than bundy tubing provided you take precautions to stop it vibrating. But that does not change the simple fact that the work hardening behaviour of copper is why it is not legal to use in most states, regardless of whether it is a serious problem.
While on this subject it should be pointed out that all brake pipes should be secured at relatively short intervals to prevent vibration and hence fatigue failures. A common problem is the brake pipe from the T on the rear axle on Series Landrovers, which must be secured, not just attached at the ends.
John
John
JDNSW
1986 110 County 3.9 diesel
1970 2a 109 2.25 petrol
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