See Figure 1
Measure the lining thickness, dimension A in the illustration. The wear limit is 0.059 in. (1.5mm); brake shoes which do not meet this standard should be replaced. Also, inspect the shoes for cracked linings or abnormal wear.
It is not unusual for the primary and secondary brake shoes to wear at different rates. Always replace both shoes, even if only one fails inspection.
REMOVAL & INSTALLATION
See Figures 2 through 15
We recommend replacement of brake shoes in axle sets for added safety and reliability. To ensure even wear, out-of-round drums should be turned (refinished) on a brake lathe whenever the shoes are replaced.
- Remove the hub cap and loosen the lug nuts.
- Raise and support the rear of the vehicle safely.
- Remove the lug nuts, tire and wheel.
- Remove the brake drum.
- With a brake tool, remove the shoe hold-down anti-rattle spring retainers. Depress the retainer while rotating it 90 degrees to align the retainer slot with the pin flanged end. Remove the retainers, springs, spring seats, and pins.
- Open the brake shoes outward against the return springs, then remove the parking brake extension link.
- Disconnect the brake shoe return springs.
- Remove the shoes from the backing plate. The secondary shoe must be disconnected from the parking brake toggle lever after withdrawing the clevis pin.
- Remove the rubber boot from behind the backing plate then slide the adjuster shim, lockplate, and adjuster springs off the back of the assembly. Remove the adjuster assembly from the backing plate.
- Clean the backing plate and adjuster assembly so they are free of all dust and dirt.
- Check the wheel cylinders. Replace or overhaul, as needed.
- Apply brake grease to the adjuster assembly housing bore, adjuster wheel, and adjuster screw. Assemble the adjuster mechanism with its screw turned all the way in. Apply brake grease to the sliding surfaces of the adjuster assembly, brake backing plate, and the retaining spring. Install the adjuster assembly to the backing plate.
- On 4wd models, make sure that after installation there is no play between the crank lever and backing plate when pulling on the lever. If play exists, adjust bolt A and locknut B .
- Assemble the secondary brake shoe to the parking brake toggle lever, then adjust the clearance.
- Before assembling the brake shoes to the backing plate, apply brake grease to the following areas: the brake shoe grooves in the parking brake extension link, the inside surfaces of the anti-rattle (retaining) spring seats, and the contact surfaces between the brake backing plate and the brake shoes.
- Assemble the brake shoes to the backing plate. Measure the inner diameter of the brake, then measure the outer diameter of the shoes (at the center). The shoe outer diameter should be 0.0098-0.0157 in. (0.25-0.40mm) less than the drum measurement; if not, adjust by rotating the star wheel adjuster.
- Install the brake drum and the wheel.
- Adjust and bleed the brakes.
Adjust the shoe-to-drum clearance by operating the parking brake lever several times.