Brake Calipers
WARNING: This page does not describe the selected car, but rather 29 other vehicles, including the 2000 Mercedes-Benz SLK230, 2000 Mercedes-Benz SL500, 2000 Mercedes-Benz S500, 2000 Mercedes-Benz S430, and 2000 Mercedes-Benz ML55. However, it is still accessible from the selected car via links, so may be relevant.
If piston is stuck, scores are present, or rust is present in cylinder bore, replace complete caliper (fixed caliper) or cylinder housing (floating caliper). Remove small rust points in cylinder bore with polishing cloth. If rust is more severe in front of groove for piston seal, use a fine abrasive paper (380-500 grain).