Mercedes-Benz W211 brake caliper drags or sticks
Why does the W211 brake caliper drag or get hot after new pads?
The most common causes are a slide pin that does not move freely in the caliper bore, and a sticking piston. Hardened grease in the slide pin bore stops the caliper from releasing properly. Cleaning and fresh grease often help; otherwise the caliper is replaced.
Why does the rear brake caliper stick only a few days after a pad change?
The piston of the original rear caliper is composite, which can collapse and not return properly. The sticking may show up only in frosty weather or after several days. The solution is usually new calipers. The brakes are safety-critical, so have a workshop check the result.
Can the rear brake drag for a reason other than the caliper?
Yes. The handbrake linkages and their joints can stick, and the handbrake drums can be scored or worn. The car can also get stuck after a wash, when a damp brake rusts fast. A few brake applications or a short drive after washing dries the brakes.