Self-Adjusting Brakes

Fig. 5 Rear Drum Type Brakes:

These brakes, Fig. 6, 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 performed with a firm pedal effort 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 drums, clean, free up and lubricate the adjusting mechanism. Then adjust the brakes, being sure the parking brake is fully released.