REMOVAL & INSTALLATION
See Figure 1
- Raise vehicle and support it with safety stands.
- Remove adjusting nut from equalizer.
- Remove retainer clip from rear portion of front cable at frame and from lever arm.
- Disconnect front brake cable from parking brake pedal or lever assemblies. Remove front brake cable. On some models, it may assist installation of new cable if a heavy cord is tied to other end of cable in order to guide new cable through proper routing.
- Install cable by reversing removal procedure.
- Adjust parking brake.
See Figure 2
- Release the parking brake.
- Raise the truck and support it with safety stands.
- Remove the cotter pin and the clevis pin from the brake lever and disconnect the clevis and lock nut from the end of the cable.
- Pull the cable and grommet out of the lower bracket. Unscrew the bracket bolt on the frame rail.
- Disconnect the end of the cable at the pedal lever, release the retaining fingers and remove the cable.
- Install the cable and check the parking brake adjustment.
- Raise the vehicle on hoist.
- Remove the adjusting nut from the equalizer.
- Unhook the connector at each end and disengage the hooks and guides.
- Install the new cable by reversing the removal procedure.
- Adjust the parking brake.
- Apply the parking brake 3 times with heavy pressure and repeat adjustment.
See Figure 3
- Raise the vehicle and support it on safety stands.
- Remove the rear wheel and brake drum.
- Loosen the adjusting nut at the equalizer.
- Disengage the rear cable at the connector.
- Bend the retainer fingers at the backing plate.
- Disengage the cable at the brake shoe operating lever.
- Install the new cable.
- Adjust the parking brake.
Duo-Servo Drum Brakes
The rear brakes serve a dual purpose. They are used as service brakes and as parking brakes. To obtain proper adjustment of the parking brake, the service brakes must first be properly adjusted as outlined earlier.
- Apply the parking brake 4 clicks from the fully released position.
- Raise and support the vehicle.
- Loosen the locknut at the equalizer.
- Tighten or loosen the adjusting nut until a moderate drag is felt when the rear wheels are rotated forward.
- Tighten the locknut.
- Release the parking brake and rotate the rear wheels. No drag should be felt. If even a light drag is felt, readjust the parking brake.
- Lower the vehicle.
If a new parking brake cable is being installed, pre-stretch it by applying the parking brake hard about three times before making adjustments.Leading/Trailing Drum Brakes
See Figures 4 and 5
- Raise the rear of the truck and support it with safety stands. Remove the wheels and brake drum.
- Measure the brake drum inside diameter.
- Turn the adjuster nut until the brake shoe maximum diameter is 0.01-0.02 in. (0.25-50mm) less than the brake drum diameter.
- Make sure that the stops on the parking brake levers are against the edge of the brake shoe web. If the cable is holding the stops off the edge, loosen the adjustment.
- Tighten the cable at the adjuster nut until the lever stops begin to move off the shoe webs.
- Loosen the adjustment nut until the lever stops are just touching the shoe webs. There should be no more than 0.019 inch (0.5mm) clearance between the stops and the webs.
- Install the drums and wheels.
- Pump the brake pedal 30-35 times with normal force. Pause about 1 second between each stroke.
- Depress the parking brake pedal 6 clicks. The wheels should be locked.
- Release the parking brake. The wheels should rotate freely.
See Figure 6
- Locate the parking brake drum assembly. Its at the back of the transmission extension housing. Remove the clevis pin from the parking brake lever.
- Set the parking brake pedal to 4 clicks.
- Connect a tension gauge to the frame of the truck with a small length of cable and a turn buckle.
- Connect the tension gauge to the bottom of the parking brake lever and tighten it to 50 lbs. (222N).
- Loosen the clevis lock nut and turn the clevis until the pin slides freely in the lever. There should be no slack in the cable.
- Install the clevis pin and a new cotter pin. Tighten the lock nut to 27 ft. lbs. (37 Nm).
- Remove the gauge and release the parking brake.