position the free piston 64 is in contact with or proximate to the upper end cap 54 this movement of the free piston 64 will cause the actuator 12 to move the sleeve 22 axially downwardly within its housing 20 so that the ports 30 of the sleeve 22 are moved to a point as shown in fig2 wherein they are close to overlapping the ports 26 of the housing 20 this position is referred to as the u201c zero position u201d in a currently preferred embodiment the movement of the free piston 64 will cause the sleeve 22 to displace 10 604 u2033 with respect to the housing 20 the first and second piston metering assemblies 36 38 are interconnected in hydraulic parallel therefore the pressure differential across the metering device 32 will also cause the incremental piston pump 90 to move from the initial position shown in fig5 a to the pressurized position depicted in fig6 a thereby displacing an additional volume of fluid from the actuator 12 the sleeve 22 will then be displaced an additional amount with respect to the housing 20 such that the ports 30 of the sleeve 22 now slightly overlap the ports 26 of the housing 20 and permit a small amount of fluid to pass through the sleeve valve 14 thus the sleeve valve 14 will be partially open it is noted that when the incremental piston pump 90 is in the pressurized position the enlarged pressure receiving end 96 of the piston member 94 will engage a restriction 106 in the shaft 108 passing through the body.