Brake Shoe: Service and Repair

Drum Brake Components:

REMOVE OR DISCONNECT
1. Raise vehicle and suitably support.
2. Mark relationship of wheel to wheel studs in bearing flange.
3. Wheel and tire.
4. Mark relationship of drum to wheel studs in bearing flange.
5. Brake drum.

Removing Actuator Spring:

6. Actuator spring. Use J 38400 to pry loop end of spring from adjuster actuator; then disconnect from web of park brake shoe.

Disengaging Retractor Spring:

NOTE: When removing the retractor spring from either shoe and lining, do not overstretch it. Overstretching reduces the spring's effectiveness.

7. Lift end of retractor spring from adjuster shoe and lining. Insert hook end of J 38400 between retractor spring and adjuster shoe web, and pry or twist to lift end of spring out of shoe web hole.

CAUTION: Keep fingers away from retractor spring to prevent fingers from being pinched between spring and shoe web or spring and backing plate.

8. Pry end of retractor spring toward axle with flat edge of J 38400 until spring snaps down off shoe web onto backing plate.
9. Adjuster shoe and lining, adjuster actuator and adjusting screw assembly.
10. Park brake lever from park brake shoe and lining. Do not remove parking brake cable from park brake lever unless lever is to be replaced.
11. Lift end of retractor spring from park brake shoe and lining. Insert hook end of J 38400 between retractor spring and park brake shoe web, and pry or twist to lift end of spring out of shoe web hole.

CAUTION: Keep fingers away from rear brake shoe springs to prevent fingers from being pinched between spring and shoe web or spring and backing plate.

12. Pry end of retractor spring toward axle with flat edge of J 38400 until spring snaps down off shoe web onto backing plate.
13. Park brake shoe and lining. If only shoes and linings are being replaced, the retractor spring does not have to be removed. Otherwise, remove retractor spring from anchor plate. Clean All parts in clean, denatured alcohol.

NOTE: Replace any parts which are of doubtful strength or quality due to discoloration from heat, over stress, or wear. Inspect Wheel cylinder for leakage, and cut or damaged boots. Do not attempt to repair wheel cylinder; replace it if leaking or damaged.

INSTALL OR CONNECT

NOTE: Lubricate the following with brake lubricant GM P/N 1052196 or equivalent: Six raised shoe pads on backing plate. Anchor surfaces on backing plate that contact lower ends of brake shoes. When installing retractor spring into either shoe and lining, do not overstretch it. Overstretching reduces the spring's effectiveness.

1. If retractor spring was removed, reinstall, hooking center spring section under tab on anchor.
2. Park brake shoe and lining, as follows:
a. Position shoe and lining on backing plate.

Pulling Spring End Onto Shoe Web:

b. Using J 38400, pull end of retractor spring up to rest on web of brake shoe.

Pulling Spring End Into Shoe Slot:

c. Using J 38400, pull end of retractor spring over until it snaps into slot in brake shoe.
3. Park brake lever to park brake shoe and lining.

Adjusting Screw Assembly Components:

4. Parking brake cable to park brake lever, if disconnected. Clean Before reinstalling, disassemble adjusting screw assembly, and thoroughly clean and lubricate it as follows: Clean adjuster screw threads with a wire brush. Wash all components in clean, denatured alcohol. Apply brake lubricant, GM P/N 1052196 or equivalent, to adjuster screw threads, inside diameter of adjuster socket, and socket face. A continuous bead of lubricant should be on the end of pivot nut and adjuster socket when threads are fully engaged. Inspect Adjuster screw threads for smooth rotation over full length.
5. Adjusting screw assembly and adjuster shoe lining:
a. Engage pivot nut with web of park brake shoe and lining and park brake lever.
b. Position adjuster shoe and lining such that shoe web engages the deep slot in adjuster socket.
6. Retractor spring into adjuster shoe and lining. Using J 38400, pull end of retractor spring up to seat on web of brake shoe; then pull end of retractor spring over until it snaps into slot in brake shoe.

Spreading Shoes To Install Adjuster Actuator:

7. Adjuster actuator.
a. Lubricate tab and pivot point on adjuster actuator with brake lubricant, GM P/N 1052196 or equivalent.
b. Using J 38400, spread brake shoes while working adjuster actuator into position.
8. Actuator spring.
a. Engage U-shaped end of spring in hole in web of park brake shoe.
b. Using J 38400, stretch spring and engage loop end over tab on adjuster actuator. Inspect Check the following to assure proper position and function of the adjuster actuator. Adjuster actuator pivot in shoe web slot. Notch in adjuster actuator on stepped edge in adjusting screw notch. Arm of adjuster actuator resting freely on star wheel teeth of adjuster screw, not trapped under teeth in a downward angle. Install J 38400 between upper ends of shoe and lining assemblies. Spread shoes and watch for proper rotation of star wheel.

NOTE: Before installing brake drum and wheel, adjust the following: Service brakes. Parking brake.

9. Brake drum.
10. Wheel and tire, aligning marks made at removal.
11. Torque wheel nuts to 140 Nm (100 ft. lbs.).
12. Lower vehicle.