Inspect the brake pads for wear using a ruler or Vernier caliper. Compare measurements to the brake specifications chart. If the lining is thinner than specification on any part of the pad or there is evidence of the lining being contaminated by brake fluid or oil, replace both brake pad assemblies (a complete axle set).
REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13
- Raise and safely support the vehicle securely on jackstands.
- Remove the wheels.
- Remove the brake drum. If the brake drum is difficult to remove, back off the brake pad self-adjuster.
Never use compressed air to blow dust from brake components.
- Vacum brake components to remove brake lining dust. If a vacuum is not available, use water dampened cloths or an appropriate brake cleaning fluid.
It is a good idea to only disassemble and assemble one side at a time, leaving the other side intact as a reference.
- Remove the brake shoe return springs, using suitable brake spring pliers.
- Disconnect the automatic adjuster cable from the anchor and unhook it from the lever.
- Remove the cable guide from the secondary shoe and anchor plate from the anchor pin.
- Remove the adjuster lever. Disconnect the lever from the spring by sliding the lever down to clear the pivot and work the lever out from under the spring.
- Disconnect and remove the brake shoe springs from the brake shoes.
- Disconnect and remove the adjuster screw assembly from the brake shoes.
- Remove the brake shoe retainers and springs.
- Remove the secondary brake shoe from the support plate.
- Remove the strut and spring.
- Remove the parking brake lever from the secondary shoe.
- Remove the primary shoe from the support plate
- Disconnect the parking brake lever from the parking brake cable.
- Thoroughly clean the support plate with brake cleaning solvent and dry completely.
- Use silicone grease to lubricate the brake support plate-to-brake shoe contact areas.
- Apply a light coating of grease to the threaded areas of the adjuster. Turn the adjuster in and out to spread the lubricant. Turn the adjuster all the way down on the screw and loosen one-half turn.
- Connect the parking brake lever to the parking brake cable. Then connect the lever to the secondary shoe.
- Install the primary shoe on the support plate
- Install the spring on the parking brake strut and engage the strut on the primary shoe.
- Install the secondary brake shoe on the support plate.
- Insert strut into secondary shoe and guide shoe into anchor pin.
- Install the anchor plate and adjuster cable eyelet on support plate anchor pin.
- Install cable guide in secondary shoe and position cable in guide.
- Assemble adjuster screw, then install between brake shoes.
Ensure the adjuster screws are installed on the correct side of the vehicle. The adjuster screws are marked "L" for left and "R" for right.
- Install the adjuster lever and spring and connect the adjuster cable to the lever.
- Install the shoe retainers and springs.
- Install the shoe return spring. Connect the spring to the secondary shoe first, and then to the primary shoe.
- Verify adjuster operation. Pull adjuster cable upward, cable should lift lever and rotate star wheel.
Ensure that the adjuster lever properly engages the star wheel teeth.
- Install the brake drum and adjust the brake shoes.
- Install the wheels.
- Lower the vehicle.
The drum brakes are self-adjusting and require a manual adjustment only after the brake shoes have been replaced, or when the length of the adjusting screw has been changed while performing some other service operation.Drum Installed
See Figure 14
- Raise and support the vehicle safely.
- Remove the rubber plug from the adjusting slot on the support plate.
- Insert a brake adjusting tool into the slot and engage the lowest possible tooth on the star wheel. Move the end of the brake spoon downward to move the star wheel upward and expand the adjusting screw. Repeat this operation until the brakes lock the wheels.
- Insert a small screwdriver or piece of firm wire (coat hanger wire) into the adjusting slot and push the automatic adjusting lever out and free of the star wheel on the adjusting screw and hold it there.
- Engage the topmost tooth possible on the star wheel with the brake adjusting spoon. Move the end of the adjusting spoon upward to move the adjusting screw star wheel downward and contract the adjusting screw. Back off the adjusting screw star wheel until the wheel spins freely with a minimum of drag. Keep track of the number of turns that the star wheel is backed off, or the number of strokes taken with the brake adjusting spoon.
- Repeat this operation for the other side. When backing off the brakes on the other side, the star wheel adjuster must be backed off the same number of turns to prevent side-to-side brake pull.
- When the brakes are adjusted, make several stops while backing the vehicle to equalize the brakes on both of the wheels.
- Lower the vehicle.
- Remove the brake drum.
- Make sure that the shoe-to-contact pad areas are clean and properly lubricated.
- Using a Brake Adjustment Gauge or equivalent, check the inside diameter of the drum.
- Measure across the diameter of the assembled brake shoes, at their widest point.
- Turn the adjusting screw so that the diameter of the shoes is 0.030 in. (0.76mm) less than the brake drum inner diameter.
- Install the drum.