PURPOSE: To obtain the normal function even in the case where a sleeve is assembled in an inner hole of a main body in any direction.

CONSTITUTION: A communication hole 35 for communicating the pressurized liquid from an accumulator 33 with an accumulator pressure chamber 20 blocked between the periphery of a piston 10, which is fitted to the inner peripheral surface of a sleeve formed with a cylinder hole 5 freely to be slid, and the cylinder hole 5 is formed at a central part of the sleeve 4 in the axial direction so as to obtain the normal operation even in the case where the sleeve 4 is assembled in the main body 2 in the opposite direction.