Drum Brake System: Service and Repair

REMOVAL








For brake drum and brake shoe replacement procedures, refer to figures for exploded views of drum brake assemblies.

Removal Note: Locknut





Uncrimp the locknut, and remove it.

Caution: Do not reuse the locknut.

Removal Note: Brake drum





If the drum is difficult to remove, push the operating lever stopper (at backing plate) upward to release the operating lever and increase shoe clearance.

Cleaning of drum brake assembly

Use a vacuum cleaner or equivalent to clean the brake assembly

Warning: Asbestos dust is a health hazard. When cleaning the brake assembly, do not use compressed air or a brush.

Brake pipe





Disconnect the brake pipe with the SST.

Caution: Brake fluid will damage painted surfaces. If it does get on a painted surface, wipe it off immediately.


INSTALLATION








1. Install in the reverse order of removal.
2. Tighten all nuts and bolts to the specified torque, referring to the torque specifications.
3. After installation:
(1) Add brake fluid and bleed air.
(2) Adjust the parking brake lever stroke.
(3) Depress the brake pedal a few times, and check that the rear brakes do not drag while rotating the wheel.

Installation Note: Brake shoes
1. Apply grease to the following points:





(1) Shoe and cylinder contact points
(2) Shoe anchor points
(3) Projections of backing plate





2. Install the operating lever assembly through the backing plate.
3. Install the return spring to the backing plate (reverse side) and the operating lever.





4. Install the shoe (trailing side) to the operating lever, then to the wheel cylinder and anchor plate.
5. Fix the shoe with the hold spring and hold pin.
6. Install the anti-rattle spring.





7. Install the return spring (lower) to the shoes (trailing side and leading side).
8. Install the leading side shoe to the operating lever, then to the wheel cylinder and anchor plate.
9. Fix the shoe with the hold spring and hold pin.





10. Install the return spring (upper).


Brake drum





1. Move the quadrant against the backing plate with a screwdriver and increase the shoe clearance.
2. Install the brake drum.

Note: The shoe clearance will be automatically adjusted by applying parking brake.


Locknut





Tighten the new locknut to the specified torque and securely stake it to the spindle groove.
Tightening torque: 98 - 177 Nm (10 - 18 m-kg, 72 - 130 ft-lb)

Caution: Do not use a pointed tool for staking.