ENGINE AR 9Y1547 - Caterpillar

Illustration 1 g00759230
(1) Hydrostatic pilot valve (2) Control lever (3) Plungers (4) Resolver block
Illustration 2 g00759228
(5) Pilot valve for the work tool (6) Control lever (7) PlungersThere are two pilot valves ( joysticks) on the machine. The two pilot valves receive hydraulic oil from separate circuits. Hydraulic oil for both circuits comes from the gear pump. The first pilot valve (1) controls the motion of the machine. The control lever (2) is moved to a desired position. The plungers (3) for the pilot valve are moved by the control lever. The plungers direct the oil flow to the resolver block (4). The resolver block directs the hydraulic oil to the actuator pistons for the piston pumps ( hydrostatic).The second pilot valve (5) controls the motion of the work tool. The control lever (6) is moved to a desired position. The plungers (7) for the pilot valve direct the pilot hydraulic oil to the respective spool in the bank valve. The work tool reacts accordingly.The control levers on both pilot valves are spring centered. When the levers are released, the levers will return to the NEUTRAL position.Refer to the Operation and Maintenance Manual, SEBU7468, "Speed and Direction Control (Joystick)" and refer to the Operation and Maintenance Manual, SEBU7468, "Work Tool Control (Joystick)" for more information on the joystick controls.