Abstract: A drum brake includes a pair of brake shoes and a hydraulic actuator which is engageable with the brake shoes to expand the latter during braking. The hydraulic actuator carries a pair of elastomeric sealing rings which are deformable during braking as a pair of pistons slidably disposed with the hydraulic actuator are movable upon a braking application. When braking is terminated, the elastomeric sealing rings return to their original stored configuration thereby retracting the pair of pistons within the hydraulic actuator. In order to retract the pair of brake shoes with the pistons through a predetermined distance, a first spring engages the pair of brake shoes substantially opposite the hydraulic actuator and biases the brake shoes toward each other while a second spring biases the brake shoes away from each other. The second spring is carried by a strut on a parking brake actuator and the strut extends from one of the brake shoes to a lever which is pivotally mounted on the other brake shoe.

Abstract: A drum brake adjustment mechanism is provided to maintain a running clearance between a pair of brake shoes and a rotatable member. The adjustment mechanism includes an extendible member which is disposed between the pair of brake shoes and engageable with a pawl which is pivotally mounted on one of the brake shoes. A resilient member encircles the extendible member and engages the other brake shoe and the pawl to bias the pair of brake shoes into engagement with a hydraulic actuator which is operable to urge the pair of brake shoes into engagement with the rotatable member. Moreover, the resilient member cooperates with the pawl to extend the extensible member when the clearance between the pair of brake shoes and the rotatable member is greater than the running clearance.

Abstract: A brake lining wear indicating system is disclosed. The system includes a probe, embedded in the lining material, which wears away as the lining wears. The probe is made of an electrically conductive material having a relatively high bulk resistivity, so that as the lining wears, the resistance of the probe changes accordingly. The resistance of the probe can then be measured to determine lining wear.

Abstract: A disc brake for an automotive vehicle is disclosed. The brake includes a unique floating connection between the caliper and the steering knuckle of the vehicle which includes a sleeve which extends through an aperture in the caliper and a bolt which extends through the sleeve to fasten the latter to the steering knuckle. A tongue-in-groove connection is provided between the caliper and the steering knuckle to prevent rotation of the caliper about the sleeve. This design provides a brake which may be manufactured at lower cost than some prior art brakes, because the brake is designed so that manufacturing tolerances are less critical.

Abstract: A drum brake adjustment mechanism is provided to maintain a running clearance between a pair of brake shoes and a rotatable member. The adjustment mechanism includes an extendible member which is disposed between the pair of brake shoes and engageable with a pawl which is pivotally mounted on one of the brake shoes. A .Iadd.single .Iaddend.resilient member encircles the extendible member and engages the other brake shoe and the pawl to bias the pair of brake shoes into engagement with a hydraulic actuator which is operable to urge the pair of brake shoes into engagement with the rotatable member. .[.Moreover, the.]. .Iadd.The single .Iaddend.resilient member cooperates with the pawl to extend the .[.extensible.]. .Iadd.extendible .Iaddend.member when the clearance between the pair of brake shoes and the rotatable member is greater than the running clearance. .Iadd.