Abstract: An improved pressure sensitive valving arrangement is provided for a power steering unit for a lift truck, and in particular for a battery powered lift truck. To the conventional implement valve is added an accumulator charging means which includes an additional valve, herein called a "blocking or control valve", which additional valve is downstream from the implement valve and which additional valve, when actuated, blocks the flow of fluid through the implement valve to thereby build up pressure for charging an accumulator. The blocking valve includes a blocking spool which operates against a pressure-actuated pilot plunger such that when the pressure in the accumulator reaches or exceeds a predetermined amount, the pilot plunger shifts the blocking spool to permit the fluid to again flow through the implement valve.