An anti-lock device for a hydraulic automobile brake system includes a housing block for receiving an eccentric directional valves, two coaxially oriented pump pistons and first and second storage chambers. So that the housing block can be made narrower, the longitudinal axes (F, G, I, J) are distributed to the corners of a quadrangle. At the same time, the common longitudinal axis (E) of the pump pistons can be located between the longitudinal axes of the storage chambers.