IDLER GP-FRONT 7Y0762 - Caterpillar

HOLD Position
Illustration 1 g01221833
(1) Passage (2) Spool (3) Spring (4) Port (5) PortIn the HOLD position, the spring (3) holds spool (2) in the centered position. No pilot oil enters the control valve through the port (4) and port (5). Any pilot oil in the pilot lines drains through the pilot valve to the tank. The spool (2) blocks the flow of pump supply oil in passage (1) .Passage (1) is common to all control valves in the bank valve. The passage has no outlet. The spool blocks the flow of pump supply oil until the operator moves the control lever.DUMP Position
Illustration 2 g01221885
(1) Port to the rod end (2) Check valve (3) Chamber (4) Pressure compensator valve (5) Check valve (6) Port to the head end (7) Spring (8) Spool (9) Passage (10) Passage (11) Passage (12) Passage (13) Passage (14) Passage (15) Passage (16) PortWhen the tilt circuit is the only hydraulic circuit in operation, the tilt circuit will have the highest signal oil pressure in the hydraulic system. When the pilot valve is moved to the DUMP position, pilot oil enter the control valve through port (16). When the pilot oil overcomes the force of spring (7), spool (8) moves to the right.When the spool moves to the right, pump supply oil flows around the spool and into passage (13). The hydraulic oil in passage (13) flows to pressure compensator valve (4). In the pressure compensator valve, the hydraulic oil flows into internal passages. The pressure compensator valve moves up. As the pressure compensator valve moves up, the cross-drilled passage is opened to an internal passage that is in the valve. Some of the hydraulic oil flows around the pressure compensator valve to chamber (3). The hydraulic oil that flows to chamber (3) is signal oil. The signal oil balances the pressure compensator valve against the hydraulic oil pressure in passage (13). This controls the flow across spool (8) .The signal oil in the internal passage