STRUCTURE AND OPERATION
As the brake drum-to-lining clearance grows, the amount of piston travel, and therefore the amount of lever trav- el, becomes greater.
When the lever travels far enough to turn the adjuster, the threads on the adjuster causes the adjusting screw to advance. As a result, the brake shoe extends.
As the brake pedal is released, the ad- juster remains in the new position while the lever retracts by one tooth. The brake drum-to-lining clearance is now correctly adjusted.