>. . .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. . .I pushed down on the
>brake pedal and almost nothing happened. I . . .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.
I had a similar problem with my Healey back a few years ago, only I found
pitting both on the pistons and the caliper body, in the grove where there
seal rests. As new calipers were $300 each, I succeeded in convincing
myself that new pistons, at $50 each, would fix the problem. They didn't.
Some calipers are 3-piece where the cylinder that holds the piston bolts on
to the main caliper body. I believe Jag calipers are this way. The Healey
has a second type of caliper which is 2-piece, split down the middle, with
the piston cylinder cast into each half. The 3-piece style can be bored and
sleaved at a reasonable price, but I couldn't find anybody who could do the
Healey calipers. I know the manual warns against splitting the halves, but
there has got to be a way to split, bore and sleave, and re-assemble them
and have them work correctly.
--
_____________ _____________ Robb Pryor,
\____________\_____________/____________/ Pyramid Technology,
\__________ __________/ Mountain View, CA 94039
\________ AUSTIN-HEALEY ________/ VOICE:(415) 335-8465
\___________________________/ USENET:robbp@pyramid.com
|