REMOVAL & INSTALLATION
It is a good idea to only disassemble and assemble one side at a time, leaving the other side intact as a reference.
- Raise and support the vehicle safely.
- Remove the brake drum.
- Disconnect the parking brake rear cable and conduit.
- Remove the brake shoe hold-down springs and brake shoe hold-down pins.
- Remove the brake shoe adjusting screw spring.
- Remove the brake shoe adjusting lever and adjuster screw.
- Remove the brake shoe retracting spring.
- Remove the brake shoes from the backing plate.
- Remove and discard the parking brake lever clip. Remove the washer.
- Remove the parking brake lever from the rear brake shoe.
To install:
- Thoroughly clean the backing plate with brake cleaning solvent and dry completely.
- Use silicone grease to lubricate the brake backing plate-to-brake shoe contact areas.
- Apply a light coating of premium grease to the threaded areas of the adjuster. Turn the adjuster in and out to spread the lubricant. Turn the adjuster all the way down on the screw and loosen one-half turn.
- Install the parking brake lever to the rear (secondary) brake shoe with a new clip.
- Position the brake shoes on the backing plate and install the brake shoe hold-down springs.
- Attach the parking brake rear cable and conduit to the parking brake lever.
- Attach the brake shoe retracting spring.
The socket end of the brake adjuster screw is stamped with "R" or "L" to indicate that it is to be installed either on the right (passenger's side) or left (driver's side) of the vehicle. The adjuster nuts can be distinguished by the number of grooves machined around the body of the nut. Two grooves indicate a right-hand adjuster nut and one groove indicates a left-hand adjuster nut. Another way to identify brake adjuster assemblies is to check thread pitch. The right side adjuster assembly has right-hand threads and the left side has left-hand threads. If installed correctly, the brake adjuster assembly will increase in length when the brake shoe adjusting lever is operated.
- Install brake adjuster screw in the slots on the brake shoes. The wider slot on the socket end must fit in the slot on the front (primary) brake shoe.
- Install the brake shoe adjusting lever on the lever pin.
- Install the brake adjusting screw in the slot on the secondary brake shoe and in the slot on the brake shoe lever. The brake shoe adjusting lever should contact the brake adjuster screw.
- Adjust the brake shoes.
- Install the drums.
ADJUSTMENTS
The drum brakes are self-adjusting and require a 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.
Drum Installed
- Raise and support the vehicle safely.
- Remove the rubber plug from the adjusting slot on the backing plate.
- Insert a Brake Adjustment Tool (D81L-1103-C) or equivalent into the slot and engage the lowest possible tooth on the starwheel. Move the end of the brake spoon downward to move the starwheel upward and expand the adjusting screw. Repeat this operation until the brakes lock the wheels.
- Insert a small screwdriver or piece of firm wire (coat hanger wire) into the adjusting slot and push the automatic adjusting lever out and free of the starwheel on the adjusting screw and hold it there.
- Engage the topmost tooth possible on the starwheel with the brake adjusting spoon. Move the end of the adjusting spoon upward to move the adjusting screw starwheel downward and contract the adjusting screw. Back off the adjusting screw starwheel until 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 adjusting spoon.
- Repeat this operation for the other side. When backing off the brakes on the other side, the starwheel adjuster must be backed off the same number of turns to prevent side-to-side brake pull.
- When the brakes are adjusted, make several stops while backing the vehicle to equalize the brakes on both of the wheels.
- Lower the vehicle.
Drum Removed
See Figure 2
Fig. Fig. 2: When using a brake adjustment gauge, first measure the inside diameter of the drum (top) and then adjust the brakes shoes to the proper outside diameter (bottom)
- Remove the brake drum.
- Make sure that the shoe-to-contact pad areas are clean and properly lubricated.
- Using a Brake Adjustment Gauge (D81L-1103-A) or equivalent, check the inside diameter of the drum.
- Measure across the diameter of the assembled brake shoes, at their widest point.
- Turn the adjusting screw so that the diameter of the shoes is 0.030 in. (0.76mm) less than the brake drum inner diameter.
- Install the drum.
INSPECTION
See Figure 3
Fig. Fig. 3: Measure brake shoe thickness in several places around the shoe
Inspect the brake shoes for wear using a ruler or Vernier caliper. Compare measurements to the brake specifications chart. If the lining is thinner than specification or there is evidence of the lining being contaminated by brake fluid or oil, replace all brake pad assemblies (a complete axle set).
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