Document GK1MDKXML6dq45gDXar8o1kyv

24 LOCKHEED Hydraulic Brakes SINGLE CYLINDER SHOE RETRACTING SPRING WHEEL CYLINDER MINOR ADJUSTMENT CAM FORWARD SHOE SHOE HOLD DOWN SPRING' OR CLIP ^/ADJUSTMENT k REVERSE ^ SHOE BRAKE LINING BRAKE SHOE SHOE TABLE ANCHOR PIN "C" l^C" WASHERS-* Figure 20 Lockheed Hydraulic Brake The Lockheed hydraulic brake con sists of two shoes, each separately pivoted on a rigidly held, adjustable anchor pin. These anchor pins can be turned to control the drum-to-lining clearance at the heel of the shoe. The clearance at the toe of the shoe is con trolled by an eccentric cam near the actuating cylinder and can be adjusted from the reverse side of backing plate. The shoes are held against the ad justing cams by the tension of the retracting spring. The activating power unit in this brake'is the hydraulic cylinder which expands both shoes against the drum with equal force, except where stepbore cylinders are used. Since 1935 many cars have been equipped with step-bore wheel cylin ders. In one case the large cylinder end is used on reverse shoe to equalize lin ing wear. In another case the large cyl inder end is used on the forward shoe to reduce pedal effort.