RonLex

Rebuilding calipers on a 924s that was stationary for 8 years. I had to pound the caliper parts apart, and I'm assuming that the two sides are supposed to slide. I'm wondering what kind of clearance is required (or how much material should I remove to make them slide again) and what kind of lubricant, if any, should be used between these two clunky pieces of metal???

marc abrams

I wouldn't remove any metal. Just brush off the rust.
Choice of lubricants are very subjective. Personality I like anti-seize for the caliper sliders.

KevinGross

I agree with Marc, there should be no need to remove metal. Consider plugging up all bores, then cleaning their surface with a wire wheel (stationary or on a drill). There are a number of products available that lubricate floating calipers, and good auto parts store will have one. Not sure of the need for them, but used sparingly perhaps they help.

Given the caliper condition, I'd look into rebuilding: removing the pistons, replacing their seals. The kits are inexpensive. Lubricate the new seals with a little brake fluid. If the bleed valve is nasty corroded, it's another cheap part worth replacing. Use a little anti-seize on its threads. Good luck!

RonLex

Thanks for the tips, folks. Getting the two parts to slide on each other took a lot of wire wheel work, then a file. I masked off those areas and painted.

I did rebuild the piston, and I feel I should mention that I had to put a film of synth grease on the rubber seal to get the piston back in at all. Brake fluid, no matter how generously applied, just wouldn't allow it to slide in. That was a bit concerning.

1 down, 3 to go!