Brake Shoe: Adjustments

These brakes have self adjusting shoe mechanisms that assure correct lining-to-drum clearances at all times. The automatic adjusters operate only when the brakes are applied as the car is moving rearward. Although the brakes are self-adjusting, an initial adjustment is necessary after the brake shoes have been relined or replaced, or when the length of the star wheel adjuster has been changed during some other service operation.
Frequent usage of an automatic transmission forward range to halt reverse vehicle motion may prevent the automatic adjusters from functioning, thereby inducing low pedal heights. Should low pedal heights be encountered, it is recommended that numerous forward and reverse stops be made until satisfactory pedal height is obtained. If a low pedal height condition cannot be corrected by making numerous reverse stops (provided the hydraulic system is free of air) it indicates that the self-adjusting mechanism is not functioning. Therefore, it will be necessary to remove the brake drum, clean, free up and lubricate the adjusting mechanism. Then adjust the brakes as follows, being sure the parking brake is fully released.

Fig. 6 Brake shoe gauge measuring inside diameter of brake drum.:

Fig. 7 Brake shoe gauge measuring outside diameter of brake shoes.:

Fig. 8 Backing off brake shoe adjustment:

ADJUSTMENT
Inasmuch as there is no way to adjust these brakes with the drums installed, the following procedure is mandatory after new linings are installed or if it becomes necessary to change the length of the brake shoe adjusting screw.
1. With brake drums removed, position the caliper shown in Fig. 6 to the inside diameter of the drum and tighten the clamp screw.
2. Next position brake shoe end of the caliper tool over the brake shoes as shown in Fig. 7.
3. Rotate the gauge slightly around the shoes to insure that the gauge contacts the linings at the largest diameter.
4. Adjust brake shoes until the gauge is a snug fit on the linings at the point of largest lining diameter. If it is necessary to back off the brake shoe adjustment, it will be necessary to hold the adjuster lever away from the adjuster screw, Fig. 8.