A demand responsive flow regulator valve for use with a power steering pump and steering mechanism has a valve spool slidably disposed in a housing and responsive to a pressure differential across an orifice for the purpose of bypassing excess pump flow. The flow control orifice establishes pressure signals proportional to pump flow to the steering mechanism. The pressure signals are operative on the valve spool to control the bypassing of excess pump flow. A spring loaded metering rod disposed in the flow control orifice increases the effective area of the orifice when pressure demand at the steering mechanism increases thereby increasing the fluid flow to the steering mechanism while simultaneously decreasing the bypass flow.