Control Valves (Hydraulic Subplate Assembly)
The hydraulic subplate assembly or main control panel (Figures 12 and 13) is mounted to the right of the driver. Mounted to the
subplate are the main winch, hoist winch, boom safety and power control valves; the system selector control valve, the boom
combination control valve and the APU emergency control valve. The spade control handle is installed on the subplate and
connected to the spade combination control valve by a mechanical linkage. The subplate has numerous ports and passages and
serves as a manifold and mount for the operator's hydraulic control valves. Bleed valves are installed in the subplate to provide a
means of bleeding portions of the hydraulic system. The subplate itself serves as a manifold and directs the hydraulic oil through
numerous passages to inlet or outlet ports of the subplate and the attached control valves.
Figure 12. Hydraulic Subplate Assembly--Left-Rear View.