Drum brakes on all Ford and Mercury vehicles employ single anchor, internal-expanding, and self-adjusting brake assemblies. The automatic adjuster continuously maintains correct operating clearance between the linings and the drums by adjusting the brake in small increments in direct proportion to lining wear. When applying the brakes while backing up, the linings tend to follow the rotating drum counterclockwise, thus forcing the upper end of the primary shoe against the anchor pin. simultaneously, the wheel cylinder pushes the upper end of the secondary shoe and cable guide outward, away from the anchor pin. This movement of the secondary shoe causes the cable to pull the adjusting lever upward and against the end of the tooth on the adjusting screw starwheel. As lining wear increases, the upward travel of the adjusting lever also increases. When the linings have worn sufficiently to allow the lever to move upward far enough, it passes over the end of the tooth and engages it. Upon release of the brakes, the adjusting spring pulls the adjuster lever downward, turning the starwheel and expanding the brakes.