The hydraulic steering units are designed to amplify the torque applied to the wheels of the motor vehicle and act convey it to the steering wheels vehicle mechanism achieving a levelling to the steering wheels (or rudder) by an angle proportional to the rotation angle of the hand wheel. The servosteering units are open center type and can be used for the steering systems of motor vehicles with a running speed bellow 40 km/h and heavy load on the axles.