>
> About 2 months ago I replaced the brake pads on my TR250. The old ones were
> almost compeltely worn so I had to push the pistons back into the caliper
> body to make room for the new pads. About 30 miles later, while driving
> up a large hill, I pushed down on the brake pedal and almost nothing
> happened. I took this opportunity to rebuild the brakes, among other
> parts, and found out what had caused the failure. The pistons had rusted
> and pitted up to, but not past, the sealing gasket in between the caliper
> body and the piston. When I pushed the pistons back into the body the
> seal was now resting on the pitted area of the piston which didn't make
> a good oil seal, and the brake fluid squirted out through the rust.
> I guess the piston boot can be expected to keep out only *almost* all
> of the moisture.
>
Yeah, it seems like british cars have this terrible disease where the
calipers rust fiercely. The only permanent solution is to get your old
calipers resleeved in stainless or brass; it costs about the same as new
calipers, but is more permanent.
I'm absolutely convinced that the problem with british cars isn't the
engineering per se, but it is the material science. SU carb's have 1
adjustment screw that is always seized, simply because it is a brass
screw in an aluminum body (I know that Webers do this all over the place,
but somehow they don't corrode in Webers. I have a suspicion that Webers
use a clever alloy instead of pure aluminium). Take apart a Lucas switch
sometime. The contacts are _copper_! Yeah, copper is a great conductor
of electricity, but it makes a crummy switch surface. I think most good
switches use gold. Stuff like this is all over the place in british cars,
and is probably the ultimate cause of a large percentage of the flakey
failures in these cars.
Joe
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