Fixed Caliper Rear Axle

Install piston into caliper bore so elevated section (marked Black) on piston points up when caliper is installed on vehicle. This reduces the tendency for brake squeak. If necessary, use Piston Turning Tongs (000 589 50 37 00) to align piston in caliper bore. See Fig 1.

Fig 1: Disassembled View Of Rear Fixed Caliper

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.