Abstract: A brake actuator includes an annular housing (10b) having first and second opposite radial faces (A and B). Cavities are formed in the housing (10b), some opening onto face (A) and some onto radial face (B). Two pistons (16) are disposed in each of the cavities and are movable under the influence of fluid pressure exerted from within the respective cavities to a braking position where the pistons (16) extend axially away from the cavity. The piston (16) bear against a backing plate of respective brake pads (68) forcing the brake pads (68) against brake discs (54 and 56). By providing cavities on both faces (A and B) of the housing (10b), an actuator can simultaneously apply brake pads to two spaced apart rotating discs (54 and 56). A plurality of actuators can be coupled together to act on a plurality of axially spaced apart brake discs to form a multi-pad multi-brake system.

Abstract: A brake shoe (10) for a drum brake system (40) is provided with a brake lining (12) having a friction surface (14) which faces braking surface (60) of a brake drum (38). The lining (12) is characterized by the provision of one or more grooves (16) extending across the friction surface (14). The shoe (10) may be incorporated in a cooled drum brake system (10) in which cooling is provided by ventilation holes in the drum (38). Cooling may be further enhanced by the provision of ventilation holes (66) in a back plate (46) of the system (40). In an alternate system, cooling is provided by sealing the drum (38) to form a space for holding a volume of oil.