A steering control piston valve has reaction chambers and respective fixed restrictor orifices having an interconnector conduit. The reaction chambers have respective inlet and outlet flow control valving which serve to permit flow from either reaction chamber to bypass the respective restrictor orifice during a steering maneuver if the steered wheels receive a road jolt. The arrangement provides for very rapid flow from the reaction chamber being decreased in volume due to the jolt force on the valve piston causing it to move oppositely to the steering direction. The flow from such reaction chamber passes to the interconnecting conduit for storage. An additional storage tank can be connected to the interconnecting conduit to increase the storage capacity if necessary. The bypassing is likewise advantageous in the event a vehicle swerves and rapid steering correction is necessary.