BMW Coupes and Sedans 1970-1988 Repair Guide

Brake Drums



See Figure 1

Brake shoes and pads may contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air. Avoid inhaling any dust from any brake surface. When cleaning brake surfaces, use a commercially available brake cleaning fluid.

  1. Support the rear of the car securely on jackstands and remove the rear wheel. On the 320i, remove the Allen bolt from the brake drum.
  3. If the drum will not come off, severe wear may have grooved the surface, causing the brake linings to prevent drum removal. To remove a drum under this situation, loosen both the brake adjuster and the hand brake cable. When loose enough, pull the drum off the axle flange.
  5. Check the contact surface of the drum for scoring. Measure the inside diameter to check for ovality. Ovality must not exceed 0.02 inches (0.5mm). The drum may be machined 0.02 inches (0.5mm) at a time to a maximum oversize of 0.03 inches (1mm).

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Fig. Fig. 1: If removing the rear drum on a 320i, the Allen bolt (arrow) must be removed prior to removing the drum

If a drum needs cutting, always cut the drums in pairs.

  1. To check the drum for cracks, hang the drum by a piece of wood and tap with a small metal object. A cracked drum will sound flat.
  3. To Install the drum, reverse the removal procedure, and adjust the brakes.
  5. Install the wheel and lower the vehicle.