CHAIN AS 5165583 - Caterpillar

Two-Stack Valve
Components Of Valve
(1) Solenoid assembly. (2) Manual actuator. (3) Coil. (4) Plunger. (5) Wire connector. (6) Valve assembly. (7) Spool. (8) Bolt hole. (9) Port A. (10) Return passageway. (11) Supply passageway. (12) Spring. (13) Cylinder port.The two-stack valve consists of two individual solenoid valves bolted together. The two solenoid valves share pump supply and tank return lines, however, they operate independently.Each solenoid valve of the two-stack valve unit consists of two major components: solenoid assembly (1) and valve assembly (6). The solenoid assembly is made up of coil (3), plunger (4), and wire connector (5). The major components of the valve assembly consists of spool (7) and spring (12). Spool (7) is attached to plunger (4).When the park brake switch is positioned in the ON position no current flows to coil (3) in the park brake solenoid valve. Spring (12) forces spool (7) and plunger (4) up. Supply oil in passageway (11) is routed to port A (9). Port A of the park brake solenoid valve is plugged.Port B (not shown) is connected to the parking brake cylinder by a hydraulic hose. When the plunger is in the up position cylinder port (13) is open to return passageway (10). The springs in the parking brake cylinder force the oil back through the solenoid valve to tank.When the park brake switch is positioned in the OFF position current flows to coil (3). The current flowing through coil (3) forces plunger (4) and spool (7) to overcome the tension of spring (12) and move down. When the plunger is in this position cylinder port (13) is open to supply passageway (11) and hydraulic pressure is routed to the parking brake cylinder.When the differential lock switch is placed in the OFF position no current flows to coil (3) of the differential lock solenoid valve. Spring (12) forces spool (7) and plunger (4) up. Supply oil in passageway (11) is routed to port A (9). Port A of the differential lock solenoid valve is plugged.Port B (not shown) is connected to the differential lock by a hydraulic hose. When the plunger is in the up position, cylinder port (13) is open to return passageway (10) and the hydraulic tank.The spring in the differential lock piston assembly forces the oil back through the solenoid valve to tank.When the differential lock switch is positioned in the ON position current flows to coil (3). The current flowing through coil (3) forces plunger (4) and spool (7) to overcome the tension of spring (12) and move down. When the plunger is in this position cylinder port (13) is open to supply passageway (11) and hydraulic pressure is routed to the differential lock.Circuit Flow
Schematic Of Ground Drive Hydraulic System
(1) Hydraulic tank. (2) Ground drive pump group. (3) Ground drive pump. (4) Charge pump. (5) Charge relief valve. (6) Charge check valve. (7) Charge check valve. (8) Oil line. (9) Differential lock piston. (10) Two-stack valve. (11) Differential lock solenoid valve. (12) Suction strainer. (13) Ground