System for bleeding a valve in a vehicle hydraulic system

摘要

A system (10) for bleeding a valve in a vehicle hydraulic system including a hydraulic directional control valve (12), in particular a selective control valve, a main spool (18) for controlling communication between a pump (32), a hydraulic reservoir (28) and first and second work ports (48, 50). The main spool (18) is movable from a neutral position to an extend position and to a retract position. The main spool (18) is also movable to respective first and second bleed positions wherein the respective work port (48, 50) is communicated with the hydraulic reservoir (28) before the other work port (50, 48) is communicated with the pump (32).