Subaru Coupes/Sedans/Wagons 1985-1996 Repair Guide

Brake Drums



Brake 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 any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

  1. Raise and support the rear of the vehicle safely on jackstands.
  3. Remove the rear tire and wheel assemblies.
  5. Matchmark the drum to the hub or hub studs for installation purposes.
  7. Pry off the center cap, then remove the cotter pin, castle nut, and center retainer washer. Remove the center washer by inserting a screwdriver into the center slit and lightly tapping.
  9. If the drum will not come off past the shoes, it will be necessary to retract the brake shoe adjusting screw. Remove the access hole cover from the backing plate and turn the adjuster to retract the linings away from the drum.

To install:
  1. Install the drum aligning the match marks made during removal.
  3. Install the center retainer washer and castle nut. Tighten the castle nut to 108 ft. lbs. (147 Nm). Install a new cotter pin.
  5. Adjust the brake shoes.
  7. Install the center cap and wheels. Lower the vehicle.
  9. Install the rear tire and wheel assemblies.
  11. Remove the jackstands and carefully lower the vehicle.


Clean all grease, brake fluid, and other contaminants from the brake drum using a suitable brake cleaner. Visually check the drum for scoring, cracks, or other damage and replace, if necessary.

Check the drum inner diameter using a brake shoe clearance gauge. There are 2 important specifications when discussing rear drum diameters. The refinish diameter is the maximum diameter to which the drum may be machined. This diameter allows room for drum wear after it has been machined and returned to service. The discard diameter is the point at which the drum becomes unsafe to use and must be discarded. NEVER refinish a drum to the discard diameter. If after refinishing the drum the diameter is within 0.030 in. (0.76mm) of the discard diameter, the drum MUST be replaced.

After removing the brake drum, inspect the inner braking surface for excessive wear or damage. If it is unevenly worn, streaked, or cracked, have it resurfaced or replaced. The standard inside diameter of the brake drum is 180mm. The maximum allowed diameter is 182mm.


Bearing Preload

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Turn the rear drum while holding a spring scale 90° from the drum's diameter to measure starting force

  1. Tighten the castle nut to 36 ft. lbs. (47 Nm), while rotating the drum back and forth to seat the bearing. Loosen the nut about 0.25 in (3mm).
  3. Then, attach a spring scale to one of the wheel studs. Pull on the spring scale at a 90 degree angle to the diameter of the brake drum and measure the force required to start the drum turning. It should be 2.6-4.0 lbs. Loosen or tighten the nut slightly to get the correct rolling resistance.
  5. When the rolling resistance is correct, bend the lockwasher over to hold the nut in place.