RETARDER LINES GROUP 9D2655 - Caterpillar

Illustration 1 g00330783
(2) Hose (3) Valve (4) Hose (5) Hose (6) Hose (7) Spool
Illustration 2 g00330804
(1) Main control valve (2) Hose (3) Valve (4) Hose (5) Hose (6) Hose
Illustration 3 g00330806
(3) Valve (7) Spool (8) "C1" Port (9) "C2" Port
Illustration 4 g00363760
(1) Pressure port (2) Tank port (3) "C2" port (4) "C1" portThis circuit allows the grapple on the boom to be opened or closed. When the hydraulic activation control lever is placed in the unlocked position, pilot oil is directed from the "A2" port through hose (2) to valve (3). Hose (2) is connected to the "IN" port of valve (3). When the trigger switch on the left control lever is depressed, current causes spool (7) in valve (3) to shift. The shift in valve (3) directs oil flow to port (8). From port (8), oil flows through hose (5) to the bottom stem of the main control valve. The main control valve stem shifts and main pump oil is directed to the lower port of the valve. The lower port of the control valve is connected to the rod end of the grapple cylinders. This causes the grapple to open.The return oil from the head end of the grapple cylinders goes into the upper port of the main control valve. Return oil from the top stem of the main control valve flows through hose (4) to port (9) of valve (3). From port (9), the oil flows through hose (6) to "B1" port of the hydraulic activation control valve. The oil flows from the "B1" port to the hydraulic tank.When the front switch on the right control lever is depressed, current causes spool (7) to shift in valve (3). The shift in valve (3) directs pilot oil flow to port (9). Pilot oil from port (9) flows through hose (4) to the top stem of the main control valve. The flow of pilot oil causes the stem to shift. The top port of the control valve is connected to the head end of the grapple cylinders. This causes the grapple to close. The return oil from the grapple would then be directed through the bottom port of the main control valve.