For the purpose of optimizing the suction behavior of a pump in an anti-locking brake system in which the pressure acting on the wheel brakes is reducible by bleeding hydraulic fluid through a return line, with a hydraulic pump whose suction chamber is connected through a suction line to a hydraulic fluid reservoir, the return line is connected to the suction chamber, a hydraulic link existing simultaneously between the return line and the suction line and a release valve and/or a reserve volume cylinder is inserted in the return line upstream of the point of connection between return line and suction line.