a vehicle power steering system which effects steering with a pair of fluid actuated cylinders , one cylinder being operatively connected to each steerable wheel . each cylinder is normally powered independently of the other cylinder so that both cylinders steer the vehicle . a pressurized fluid flow from a single source is divided for parallel flow along companion fluid flow paths to the individual cylinders . in response to a pre - determined pressure decrease sensed in one of those fluid flow paths a pressure responsive fluid diverter automatically diverts fluid flow from the reduced pressure flow path to the companion path so that all pressurized fluid in the system is then utilized to power one of the cylinders .