Electrohydraulic motor vehicle brake system and method for operating the same

The invention relates to a technique for operating an electrohydraulic motor vehicle brake system comprising a master cylinder (or any other cylinder-piston arrangement) that can be supplied with a hydraulic fluid from a reservoir, an electromechanical actuator for actuating a piston accommodated in the master cylinder, a wheel brake that can be coupled to the master cylinder, and a stop valve provided between the master cylinder and the wheel brake. According to an aspect of this technique, the method comprises the steps of: controlling the electromechanical actuator to build up hydraulic pressure on the wheel brake; controlling the stop valve to hold the hydraulic pressure already built up on the wheel brake; controlling the electromechanical actuator to take in hydraulic fluid from the reservoir while monitoring a time response of a pressure drop in the master cylinder associated with the take-in; and interrupting the take-in depending on a result of the monitoring.