143.42017 Brake Caliper Kit - High Performance Disc Brake Caliper Set for Cars & Trucks - Perfect for Brake Repair & Maintenance

Rebuilding old calipers is not that difficult, just did a pair of rear ATE calipers on a 1989 300E. Can get at least one piston out with even the compressed air from a tire pump, but can use two flat-head screwdrivers under front rim of piston and body of caliper to literally fulcrum the pistons out. Make sure you observe the positioning of any raised rim on the front of the piston before popping them out; this BMW, Mercedes feature is to reduce brake vibration /rotational torque to the pads upon braking.Make sure that any corrosion to the piston surfaces is totally cleaned off, fingernail works fine without scarring the mirror finish on the pistons. If piston is scratched or heavily corroded, brake fluid is very corrosive, replace the piston for about $12 each from Centric. The inner o-ring that fits in the piston bore seems like it is always too big to fit into the groove, but two hands and two fingers holding and pushing it into place will work. Use acaliper lubricant like what ATE puts out for rebuilds and job will go much smoother. Use C-clamp or spreader to make sure pistons all of the way into bores when finished, and make sure that dust seal boot is flush with the caliper surface also.$15 in parts per caliper, clean body of caliper with degreaser and toothbrush, wire brush too harsh. Dry, one to two coats of Rustoleum Rust Reformer, and then DupliColor Caliper Paint, use brush instead of spray that get everywhere, in the color that pleases you. So maybe $25 in materials per caliper, but rebuilds go for about $75 to $100, well worth your time and you know the job was done correctly.