Drum Brakes

Drum And Spindle:

DRUM REMOVAL
1. Raise and support vehicle.
2. Remove wheel cover and nut covers as required.
3. Remove tire and wheel assembly.
4. Remove drum retainers.
5. Remove drum. If drum will not come off, back off brake adjuster screw as follows:





- Pry rubber plug from rear brake backing plate inspection hole.
- Remove the brake tube-to-axle retention bracket. This will allow sufficient room for insertion of tools.
- Use a screwdriver and brake tools to disengage brake shoe adjusting lever and back off the brake adjuster screw.

6. Use an industrial vacuum cleaner such as Rotunda Brake/Clutch Service Vacuum or Rotunda Brake Parts Washer or equivalent, to remove all dust from rear brake backing plate and interior of the brake drums.

HUB REMOVAL
1. Remove hub cap grease seal from wheel hub assembly and discard rear hub cap grease seal.
2. Remove rear axle wheel hub retainer and discard.
3. Remove wheel hub from rear wheel spindle.

HUB INSTALLATION
1. Position wheel hub on rear wheel spindle.

CAUTION: To prevent damage to threads, do not use power or impact-type tools to tighten the rear axle wheel hub retainer.

2. Install new rear axle wheel hub retainer and tighten to 255-345 Nm (188-254 ft. lbs.).
3. Install new rear hub cap grease seal using a 1-7/8 inch x 3/4 inch drive socket.

DRUM INSTALLATION





NOTE: The rear drum brakes are self-adjusting and require a manual adjustment only after the brake shoes and linings have been replaced or when the length of the brake adjuster screw has been changed while performing some other service operation. The manual adjustment is performed with the brake drum removed, using a brake adjustment gauge

PRE-CHECKS
- When adjusting the rear brake shoe and lining, check the front parking brake cable and conduit and rear parking brake cables for proper adjustment and freedom of movement.
- Make sure the equalizer operates freely.
- When adjusting the rear brake shoes and linings, check the parking brake lever for proper adjustment and freedom of movement.
- Make sure that the adjuster mechanism operates freely with the brake shoes and linings centered on the rear brake backing plate.
- Refer To: Parking Brake for servicing.

MANUAL DRUM ADJUSTMENTS
1. Apply a small quantity of Silicone Brake Caliper Grease and Dielectric Compound to points where the shoes contact the rear brake backing plate. Do not get lubricant on linings.
2. Determine inside diameter of the drum braking surface using a brake adjustment gauge.
3. Adjust the brake shoes and lining's diameter to fit the gauge. Line the brake shoes and linings up vertically so the flats on the bottom of the brake shoes and linings are aligned approximately 1.5mm (0.05 inch) above the bottom of the brake shoe abutment plate before setting the gauge diameter.
4. Hold automatic brake shoe adjusting lever out of engagement while rotating adjusting screw. Lubricate if necessary. Make sure adjusting screw rotates freely. Refer to Brake Shoe/Service & Repair for adjuster service.
5. Rotate brake adjustment gauge around brake shoes and linings to make sure of proper setting.
6. Install brake drum as described.
7. Install tire and wheel assembly. Tighten lug nut to 115-142 Nm (85-104 ft. lbs.). Do not use power or impact-type tools; use a torque wrench.
8. Install the wheel cover and nut covers as required.
9. Complete adjustment by applying brake pedal several times with a minimum of 111 Nm (25 lbs) force.
10. After brake shoes and linings have been properly adjusted, check operation of brakes by making several stops from varying forward speeds.