stuck brake pads, or brake pads very hard to slide into the caliper?? A very common condition, especially on 190's and 300E's (W210 and W124 chassis). 99% of the time a stuck pad is just that, very rarely is the piston siezed. I often have to unbolt the caliper and then pound out the pads. I use a flat file and then a 3-sided file to get into the corners, then the pads will slide easilyinto the caliper. If the piston is siezed, do your yourself a favor and buy OEM parts. I often remove aftermarket brake parts because the customer cannot put up with the brake squeal anymore....