Abstract: The invention relates to a braking system for motor vehicles, the system comprising a hydraulic operating brake provided with two separate line circuits (14, 18) connecting a main brake cylinder (20) to brake devices (12) associated with the vehicle wheels by means of an antilock device (16), and a parking brake. According to the invention, an auxiliary cylinder (26) comprising an auxiliary piston (32) that can be displaced by an actuating device (48) and acts on the brake devices (12) during the displacement thereof by means of the liquid columns in the line circuit, and a valve (42) for locking the line connection between the main brake cylinder (20) and the respective brake devices (12), are arranged in at least one of the line circuits (18) between the antilock device (16) and the main brake cylinder (20).