Patent ID: 7419456

Claim:
A hydraulically clutch actuation device in a vehicle for increasing a functional reliability for a hydraulic circuit of a hydraulically actuatable clutch having a release cylinder ( 5 ) actuated by a master cylinder ( 3 ) via hydraulic pipes ( 6 , 7 ), and the release cylinder ( 5 ) having a primary piston ( 14 ) and a secondary piston ( 16 ) such that variable spacing between the primary and the secondary pistons ( 14 , 16 ) compensates for wear of the hydraulically actuatable clutch, and the hydraulic circuit having a pressure reservoir ( 25 ) and a pressure-reservoir filling device, wherein the pressure reservoir ( 25 ) is coordinated with a pressure-monitoring/pressure-supply device ( 28 ) which determines, in the hydraulic circuit, a reference operating pressure and a differential pressure such that, when the vehicle is at standstill and a motor is shut off, the reference operating pressure is reduced to a static pressure.