your brake calipers are rusty or not functioning correctly (i.e. the pistons in the calipers are frozen), there is a good possibility that the calipers need to be replaced. We offer new calipers for most popular Mercedes® models. Make sure to observe any VIN number applications and brand specific (ATE, Bendix, etc) applications in the note fields below. Never ever separate the caliper halves. If you do, you will have to replace the complete caliper. The calipers are not meant to be separated and the seals between the halves are not available as a spare part. Also remember that the caliper brands must match per axle. (You can't have one Bendix and one ATE on the front axle, etc.)