Disc brake assembly

A disc brake assembly for a vehicle wheel on a vehicle, wherein the wheel includes a hub journaled to an axle on the vehicle, the disc brake assembly is within the confines of the wheel and concentric with the axle, the disc brake assembly including a housing mounted to the vehicle and a radial disc within the housing and means mounting the disc to the wheel, the disc having at least a first radial planar friction surface and a first brake shoe provided adjacent the first planar friction surface movable axially towards and away from the first friction surface of the disc for friction engagement therewith and release thereof, means provided for restraining the first brake shoe from rotating with the disc, an intermediate wall member mounted within the housing and fixed thereto extending parallel with the radial disc and located such that the first brake shoe moves axially between the intermediate wall and the radial disc, a movable spring abutment means mounted for axial movement within the housing between the intermediate wall and the housing wall such that the intermediate wall is between the movable spring abutment means and the first brake shoe, rigid pusher link members extending between the spring abutment means and the first brake shoe pass through the intermediate wall such that the spring abutment means moves in unison, axially with the first brake shoe, a spring means extending between the housing wall and the spring abutment means such that the spring urges against the spring abutment means to press the first brake shoe against the first friction surface of the disc, and a first fluid bladder being provided between the intermediate wall and the spring abutment means whereby the first bladder, when expanded, forces the spring abutment means to overcome the spring means to release the first brake shoe from the first friction surface of the disc.