Adjust Parking Brake: Adjust

6 - Using a screwdriver, rotate the adjusting wheel until the brake shoes abut the parking brake drum and the wheel or the brake disk can no longer be turned by hand. See Fig 1.
Adjustment direction for applying the brake shoes:
1. Right Side
  
  Turn the adjusting wheel from the bottom upwards.
2. Left Side
  
  Turn the adjusting wheel from the top downwards.
7 - Turn back the adjusting wheel until the wheel or brake disc can be turned completely, freely by hand. When loosening the adjusting wheels ensure that both sides are turned back by the same number of teeth. 12 to 15 teeth.

Fig 1: Identifying Adjusting Wheel

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.