Chrysler RAM50/D50/Arrow 1979-1993 Repair Guide

Brake Drums



Brake pads and shoes 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 brake surfaces! When cleaning brakes, use commercially available brake cleaning fluids.

  1. Block the front wheels, raise the vehicle at the rear and support it safely on jackstands. Make sure the parking brake is released.
  3. Remove the rear wheels.
  5. Remove the brake drum by pulling it towards you. If the drum is difficult to remove, first check that the parking brake is fully released and that the cables to the wheels are not binding. Then follow either of these procedures:
    1. Remove the cover from the adjustment hole at the rear or back face of the backing plate.
    3. Insert a small prytool into the adjustment hole and use it to separate the adjustment lever from the adjuster.
    5. Use a brake adjusting tool or prytool to turn the star wheel and loosen the brake adjustment. Turning the wheel in the correct direction will contract the shoes away from the drum.
    7. If the drum has additional holes drilled in it (not all do), insert two M8;ts1.25 bolts.
    9. Turn the bolts tighter; they will press on the hub and force the drum off the brake shoes. Remember to turn the bolts alternately and evenly; if the drum is cocked, it can cause damage as it comes off (if it comes off at all).

  7. Before reinstalling the drum, the brake shoes must be in the correct position. If the shoes are expanded too far the drum simply won't go over them. Refer to the brake shoe removal and installation procedures in this section for detailed instructions on setting the shoe clearance.
  9. Install the drum onto the rear axle lug studs. Push it until it is set flat and completely in as far as it will go.


See Figure 1

Measure the inside diameter of the drum with an inside micrometer at a number of different positions. Compare it with the specifications listed in the Brake Specifications chart in this section. If the drum is worn past the limit at any point, it must be replaced. Additionally, the diameter should be constant at all points measured. An out-of-round condition may cause vibration under braking.

Mopar gives no limits for machining drums to remove uneven wear other than the absolute maximum diameter (wear limit). If the drum is worn unevenly around its diameter or has wear grooves, you may be able to salvage it by having it machined BUT machining must not increase the diameter past the specified limits. If it does, the drum must be replaced.

Drums, particularly the larger ones, can crack. Check the inner and outer surfaces and the area around the wheel lug holes for any sign of hairline cracks. Obviously, if any are found, the drum is useless.

Click image to see an enlarged view

Fig. Fig. 1: Use a micrometer or ruler to measure the inside diameter of the brake drum at several locations around the circumference