Remove the wheel and drum.
Inspect the shoes for proper thickness. The lining should be at least 1/32 in. (0.8mm) above the rivet head for riveted brakes and 1/16 in. (1.6mm) above the mounting surface for bonded brake linings.
Inspect the linings for even wear, cracking and scoring. Replace as necessary.
REMOVAL & INSTALLATION
See Figures 1 through 11
The brake shoes should be replaced in axle pairs. Failure to replace the component in pairs may cause unequal braking action and premature wear.
Raise and safely support the vehicle.
Remove the tire and wheel assemblies, then remove the brake drum.
If unsure of spring positioning, finish one side before starting the other and use the untouched side as a guide.
Fig. 1: Use a commercially available spray cleaner to remove brake dust from the components
Using tool J 8049, J 29840 or equivalent brake spring remover and installer, unfasten the primary and secondary shoe return springs from the anchor pin, but leave them installed in the shoes.
Fig. 2: Use a suitable tool to remove the return springs
Fig. 3: Unfasten the primary return spring, then ...
Fig. 4: ... remove the secondary return spring
Remove the hold-down springs, and pins using suitable pliers or brake tool.
Fig. 5: Use the brake tool to compress the hold-down spring and twist the plate to free the pin
Fig. 6: Once the pin and slot on top of the spring plate are aligned, separate the hold-down spring and pin
While lifting up on the actuator lever, remove the actuator link.
Fig. 7: Lift up on the actuator lever and remove the return spring, then ...
Fig. 8: ... remove the actuator link
Remove the actuator lever, lever return spring and the bearing sleeve.
Remove the parking brake strut and spring.
Remove the brake shoes, which are held together by the lower spring, after disconnecting the parking brake cable from the backing plate.
Fig. 9: Remove the brake shoe assembly which is held together by the lower spring
Disconnect the adjusting screw assembly and adjusting screw spring from the brake shoes.
Remove the retaining ring, pin and parking brake lever from the secondary brake shoe.
Lift the wheel cylinder dust boots and inspect for fluid leakage.
Thoroughly clean and dry the backing plate.
Fig. 10: Exploded view of the drum brake components
Remove, clean and dry all parts still on the old shoes with denatured alcohol. Lubricate the star wheel shaft threads and transfer all the parts to the new shoes in their proper locations.
To prepare the backing plate, lubricate the bosses, anchor pin and parking brake actuating lever pivot surface lightly with brake lubricant GM part no.(NNN) NNN-NNNN or equivalent.
Install the parking brake lever on the secondary shoe with the pin and retaining ring.
Install the adjusting screw assembly and adjusting screw spring on the shoe and lining assembly.
Position the shoe and lining assemblies after attaching the parking brake cable.
Spread the shoes apart, install the parking brake strut and strut spring. The end without the strut spring should engage the parking brake lever and secondary shoe and lining. The end with the strut spring should engage the primary shoe and lining.
In the next step, the bearing sleeve must be installed between the secondary and lining and the actuator lever. Refer to the accompanying figure.
Fig. 11: View of the bearing sleeve location
Install the bearing sleeve, actuator lever and lever return spring.
Install the hold-down pins and springs.
Fasten the actuator link on the anchor pin. While holding up the lever, fasten the actuator link into the lever.
Secure the shoe return springs, using tool J 8057 or equivalent pliers.
Adjust the brakes using the procedure located in this section.
Aligning the marks made during removal, install the brake drum.
Install the tire and wheel assembly.
Carefully lower the vehicle, then tighten the lug nuts to 103 ft. lbs. (140 Nm).
Adjust the parking brake, as outlined later in this section.
The drum brakes are designed to self-adjust when applied with the car moving in reverse. However, they can also be adjusted manually. This manual adjustment should also be performed whenever the linings are replaced.