Ford Mustang 1989-1993 Repair Guide




The drum brakes are self-adjusting and require manual adjustment only after the brake shoes have been replaced or when the length of the adjusting screw has been changed while performing some other service operation, such as removing the brake drum.

To adjust the brakes, follow these procedures:

Drum Installed

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Use a brake spoon to adjust the rear brakes when the drum is still installed

  1. Raise and support the rear end on jackstands.
  3. Remove the rubber plug from the adjusting slot on the backing plate.
  5. Insert a brake adjusting tool into the slot and engage the lowers possible tooth on the starwheel. Move the end of the tool downward; this moves the starwheel tooth upward and expands the adjusting screw. Repeat this operation until the brakes lock the wheel.
  7. Insert a small tool or piece of stiff wire into the adjusting slot. Use it to push the automatic adjusting lever out and free of the starwheel and hold it there.
  9. Engage the topmost tooth on the starwheel with the adjuster tool. Move the end of the tool upward (driving the tooth of the wheel downward) to contract the adjusting screw. Back off the starwheel until the brakes unlock and the wheel spins freely with a minimum of drag. Keep track of the number of turns that the starwheel is backed off or the number of strokes taken with the brake tool
  11. Repeat the process for the brakes on the other side. The starwheel adjuster must be backed off the same number of turns as the first side to prevent side-to-side brake pull.
  13. Remove the safety stands and lower the vehicle. Road test the vehicle.
  15. When the brakes are adjusted, make several stops while backing the vehicle. This will equalize the brakes at both wheels.

Drum Removed

See Figures 2 and 3

Click image to see an enlarged view

Fig. Fig. 2: Measure the installed brake shoes to determine the proper adjustment

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Fig. Fig. 3: Measure the internal diameter of the drum and set the brake shoes to 0.030 inch (0.76mm) less than the measure amount

Brake friction material 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. Make sure the shoe-to-contact pad areas are clean and well lubricated.
  3. Use an inside caliper to check the inner diameter of the drum. Measure across the diameter of the assembled brake shoes at their widest point.
  5. Turn the adjusting screw so that the diameter of the shoes is 0.030 in. (0.76mm) less than the brake drum inner diameter.
  7. Install the drum.