Abstract: The invention relates to an actuating apparatus (12) with automatic clearance adjustment for a vehicle hydraulic disk brake and includes a housing (14) having a base (16) and a shell (18) in which an open cylinder bore (20) is provided. For actuating the brake, a piston (24) is hydraulically displaceable in the bore. A mechanical actuating device for displacing the piston in the bore and for compensating lining wear comprises an expanding device (34) acting axially in a brake actuating direction and a length adjustable strut between the expanding device and the piston. The strut is formed by a first strut part (52) having a bolt shaped end, which is screwed into a second, substantially sleeve shaped strut part (54), which rests with a conical flange (68) against the piston. Between the bolt shaped end of the first strut part and the second strut part there is a cavity (90) which is to be filled with brake fluid and closed off in a fluid tight manner at one end.

Abstract: The invention relates to an actuating apparatus (12) with automatic clearance adjustment for a vehicle hydraulic disk brake and includes a housing (14) having a base (16) and a shell (18) in which an open cylinder bore (20) is provided. For actuating the brake, a piston (24) is hydraulically displaceable in the bore. A mechanical actuating device for displacing the piston in the bore and for compensating lining wear comprises an expanding device (34) acting axially in a brake actuating direction and a length adjustable strut between the expanding device and the piston. The strut is formed by a first strut part (52) having a bolt shaped end, which is screwed into a second, substantially sleeve shaped strut part (54), which rests with a conical flange (68) against the piston. Between the bolt shaped end of the first strut part and the second strut part there is a cavity (90) which is to be filled with brake fluid and closed off in a fluid tight manner at one end.