A brake system including a master cylinder connected to wheel brakes is supplemented by a fluid return system made up of return pumps so that the braking pressure can be adjusted in the wheel brakes. In order to extend this system to a brake system which permits the generation of wheel brake pressure without the application of the brake pedal, the suction side of at least one return pump is connected to the pressure side of a charging pump which aspirates fluid directly from the supply reservoir. To prevent the pressure in the low-pressure range of the system from rising excessively high, the charging pressure of the pump is adjusted so that it only slightly exceeds the precharging pressure of the suction side of the low-pressure accumulator.