Abstract: A gerotor pump is described for use with non-compressible fluids such as automotive coolant or hydraulic oil. The pump includes three separate pump outlet ports, a bypass return passage, find an integral four position spool valve. Increasing back pressure from a downstream load is sensed be the spool valve which moves accordingly to restrict the fluid supplied. In the first position a full flow fluid is supplied to the load from all three ports. In the second position one port is vented to the bypass and the flow from the other two ports is directed to the load. In the third position two ports vent to bypass, and one ports drives the load. In the fourth position all ports vent to bypass. In each case flow vented to bypass is not first compressed, permitting a smaller motor to be used.