A twin power valve assembly (10) for a hydraulic braking system having a single body (16) with twin power valve arrangements, each having a spool (36, 36′) with a longitudinally extending passageway (36D, 36D′) for providing a modulation of the pressure applied to the brakes, and an integral balance piston (60, 60′) contained within the body (10) that equalizes the pressure applied to the left and right hand brakes when both brakes are applied.