A spool valve for controlling fluid communication among hydraulic cylinders operating control and slave portions of a surgical device. The spool valve may be used to disconnect the control and the slave portions from one another such that there is no fluid communication between the control and slave portions. The spool valve may be used to engage or allow fluid communication between the control and slave. The spool valve may also be used to allow fluid communication between the slave and control portion and a fluid reservoir, thus allowing the hydraulic system to replenish fluid lost to evaporation, leakage, or other escape. The spool valve includes a body portion having at least two ports and a spool having at least one passageway moveable to a position so as to communicate with the at least two ports.
