I have replaced the rubber components in brake calipers many times. It is very easy, and the only thing that can go wrong is that you cut the piston seal putting the piston in.

I have never re-condidtioned pistons or bores, and would not for the simple reason that any polishing or piston or bore will ruin it for further service.

Don't mistake rebuilding a caliper for repair/reconditioning -- I take rebuilding to mean replacing wear parts (seal and dust boot, heat shield, springs) ONLY. Any corrosion or "crud" that cannot be removed with a cloth and brake parts cleaner condems the caliper for further use.

Restoring pistons cannot be done -- new pistons will be required if damaged, and must be oversized if the bore in the caliper is machined. The bores and pistons are chrome plated, and the plating must be renewed for the caliper to work correctly. It should be obvious this is not a DYI project!

Ryan:

The low speed growling is a sign the rear pads are shot -- replace them pronto. If there is a palpable ridge at the outer edge of the rotor, replace those, too -- $45 apiece, cheap at the price, else the pads will collide with the retaining spring on ATE calipers, jam, and seize the pistons in the bores. Ugly.

I stick with MB pads, and please, please, break them in properly -- no hard stops for at least 50 miles of city driving -- else you will melt the adhesive, glaze the pads, and have crappy brakes until you replace the pads again!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!