Drum Brake System: Service and Repair
REMOVAL
1. INSPECT SHOE LINING THICKNESS
Remove the inspection hole plug, and check the shoe lining thickness through the hole.
If less than the minimum, replace the shoes.
Minimum thickness: 1.0 mm (0.039 inch)
2. REMOVE REAR WHEEL
3. REMOVE BRAKE DRUM
HINT: If the brake drum cannot be removed easily, do the following steps.
a. Remove the adjusting hole plug in the backing plate.
b. Insert a screwdriver through the hole in the backing plate, and hold the automatic adjusting lever away from the adjusting bolt.
c. Using another screwdriver, reduce the brake shoe adjustment by turning the adjusting bolt.
4. REMOVE REAR SHOE
a. Using SST, disconnect the return spring.
SST 09703-30010
b. Using SST, remove the shoe hold-down spring, cups and pin.
SST 09713-00010
c. Disconnect the anchor spring from the rear shoe and remove the rear shoe.
d. Remove the anchor spring from the front shoe.
5. REMOVE FRONT SHOE
a. Using SST, remove the shoe hold-down spring, cups and pin.
SST 09713-00010
b. Remove the return spring from the front shoe.
c. Remove the front shoe with adjuster.
d. Disconnect the parking brake cable from the front shoe.
Remove E-Ring And C-Washer:
6. REMOVE ADJUSTER FROM FRONT SHOE
a. Remove the adjusting lever spring.
b. Remove the adjuster.
7. REMOVE AUTOMATIC ADJUSTING LEVER AND PARKING BRAKE LEVER
a. Remove the E-ring.
b. Remove the automatic adjusting lever.
c. Remove the C-washer.
d. Remove the parking brake lever.
8. REMOVE AND DISASSEMBLE PARKING BRAKE BELLCRANK
a. Remove the clip and disconnect the parking brake cable.
b. Remove the tension spring.
c. Remove the 2 bolts and bellcrank.
Torque: 13 Nm (130 kgf cm, 9 ft. lbs.)
d. Remove the bellcrank boot from the bellcrank bracket.
e. Remove the C-washer and pin.
f. Remove the parking brake bellcrank from the bellcrank bracket.
9. REMOVE WHEEL CYLINDER
a. Using SST, disconnect the brake line. Use a container to catch the brake fluid.
Torque: 15 Nm (155 kgf-cm, 11 ft. lbs.)
SST 09023-00100
b. Remove the 2 bolts and the wheel cylinder.
Torque: 10 Nm (100 kgf-cm, 7 ft. lbs.)
10. DISASSEMBLE WHEEL CYLINDER
Remove the these parts from the wheel cylinder.
1. 2 boots
2. 2 pistons
3. 2 piston cups
4. Spring
INSPECTION
1. INSPECT DISASSEMBLED PARTS
Inspect the disassembled parts for wear, rust or damage.
Fig. 3 Measuring Brake Drum Inside Diameter:
2. MEASURE BRAKE DRUM INSIDE DIAMETER
Using vernier calipers, measure the inside diameter of the drum.
Standard inside diameter: 295.0 mm (11.614 inch)
Maximum inside diameter: 297.0 mm (11.693 inch)
If the drum is scored or worn, the brake drum may be lathed to the maximum inside diameter.
Fig. 4 Measuring Brake Shoe Lining Thickness:
3. MEASURE BRAKE SHOE LINING THICKNESS
Using a ruler, measure the shoe lining thickness.
Standard thickness: 6.0 mm (0.236 inch)
Minimum thickness: 1.0 mm (0.039 inch)
If the shoe lining is less than the minimum, or shows signs of uneven wear, replace the brake shoes.
HINT: If any of the brake shoes have to be replaced, replace all of the rear brake shoes in order to maintain even braking.
4. INSPECT BRAKE LINING AND DRUM FOR PROPER CONTACT
If the contact between the brake lining and drum is improper, repair the lining with a brake shoe grinder, or replace the brake shoe assembly.
INSTALLATION
Installation is in the reverse order of removal.
NOTICE: Apply lithium soap base glycol grease and high temperature grease to the parts indicated by the arrows.
1. ADJUST BELLCRANK
a. Lightly pull the bellcrank in direction A until there is no slack at part B.
b. In this condition, turn the adjusting bolt so that dimension C will be 0.4 - 0.8 mm (0.016 - 0.031 inch).
c. Lock the adjusting bolt with the lock nut.
d. Connect the parking brake cable to the parking brake bellcrank and install the clip.
e. Install the tension spring.
2. CHECK OPERATION OF AUTOMATIC ADJUSTING MECHANISM
a. Move the parking brake lever of the rear shoe back and forth, as shown. Check that the adjusting bolt turns.
If it does not turn, check for incorrect installation of the rear brakes.
b. Adjust the adjuster length to the shortest possible amount.
c. Install the drum.
d. Pull the parking brake lever all the way up until a clicking sound can no longer be heard.
Fig. 3 Measuring Brake Drum Inside Diameter:
3. CHECK CLEARANCE BETWEEN BRAKE SHOES AND DRUM
a. Remove the drum.
b. Measure the brake drum inside diameter and diameter of the brake shoes. Check that the difference between the diameters is the correct shoe clearance.
Shoe clearance: 0.5 mm (0.020 inch)
If it is incorrect, check the parking brake system.
4. FILL BRAKE RESERVOIR WITH BRAKE FLUID
5. BLEED BRAKE SYSTEM
Brake Bleeding
6. CHECK FOR LEAKS