Except SL320, SL500 & SLK230

Remove one wheel lug bolt at each rear wheel. Preload automatic parking brake cable adjuster. See PRELOADING AUTOMATIC PARKING BRAKE CABLE ADJUSTER .
Rotate wheel until lug bolt hole is positioned over parking brake adjuster (approximately 45 degrees upward toward rear). See Fig 1. Use a flat-blade screwdriver inserted through lug bolt hole to turn star wheel adjuster until rear wheel will not rotate. Back off adjuster until wheel will rotate without drag.
Repeat step 2) for opposite rear wheel. Ensure that adjuster is backed off the same number of teeth at each wheel. Install wheel lug bolts and tighten to specification. See TORQUE SPECIFICATIONS .

Fig 1: Adjusting Parking Brake Shoes

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.