A vehicle brake system, comprising a hydraulically controllable disk brake device, which has an electromechanical actuating device for activating a parking brake function, wherein the vehicle brake system has a hydraulic circuit having a hydraulic pressure source and controllable hydraulic functional elements in order to hydraulically control the disk brake device according to a service brake action of a driver or according to an automatic activation of a driving assistance system, wherein the vehicle brake system further comprises a control device in order to control the electromechanical actuating device according to a parking brake action of the driver or according to an automatic activation of the parking brake function. In order to avoid overload states the control device is designed to control at least one of the hydraulic functional elements in such a way that, before the parking brake function is activated by controlling the electromechanical actuating device, a hydraulic volume currently acting on the disk brake device in order to produce a hydraulic pressure that causes a service brake action can be hydraulically isolated.