HYDRAULIC MOTOR VEHICLE BRAKE SYSTEM, METHOD FOR OPERATING THE SAME AND CONTROL UNIT FOR THIS

A hydraulic motor vehicle brake system is specified with a device for generating a hydraulic fluid pressure. The device comprises an electrically controllable actuator and a piston in a pressure chamber, which is movable by means of the electrically controllable actuator for changing a hydraulic fluid pressure in the pressure chamber. The brake system also comprises a wheel brake pressure control device with a reservoir for the storage of hydraulic fluid discharged from a motor vehicle wheel brake in a pressure reduction phase, wherein the reservoir is fluidically coupled to the pressure chamber. A control system of the brake system is designed to output a control signal for the actuator in the event of a detected loss of function of the control device and in the event of a detected critical filling volume of the reservoir with hydraulic fluid during operation of the control device, which causes the piston to be driven back for pressure reduction in the pressure chamber with suction of hydraulic fluid from the reservoir.