VALVE GP-PILOT 1659603 - Caterpillar

At operating temperature, the hydraulic oil is hot and under pressure. Hot oil can cause burns. Sudden movement of the machine or release of oil pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the following procedure before working on the hydraulic and steering systems.
a. Move the machine to a smooth horizontal location. Move away from any working machines and personnel. Lower all implements to the ground. Install the wheel lean pin in front axle.b. Permit only one operator on the machine. Keep all other personnel either away from the machine or in the view of the operator.c. Activate the parking brake. Place all implements on the ground and put the blade in the "FLOAT" position.d. Stop the engine.e. Turn the steering wheel back and forth several times to relieve pressure in the steering accumulator.f. Carefully loosen the filler cap on the hydraulic tank to release pressure in the tank.g. Be sure all hydraulic pressure is released before any fitting, hose, or component is loosened, tightened, removed or adjusted.h. Tighten the cap on the hydraulic tank.i. The pressure in the hydraulic system must be released before lines or components can be removed.
Hydraulic pressure can exist in the hydraulic lines between the control valves and the cylinders with the engine stopped. Manually relieve pressure before working on any hydraulic circuit.
2. Disconnect solenoid wiring harness (6).3. Put identification marks on hoses (1) for assembly purposes. Disconnect hoses (1) from manifold (2). Plug the fittings of the hoses in order to prevent the loss of hydraulic oil, and in order to keep dirt out of the hydraulic system.4. Remove hoses (7) from manifold (2). Plug the fittings of the hoses in order to prevent the loss of hydraulic oil, and in order to keep dirt out of the hydraulic system.5. Remove bolt (4) and the washer from manifold (2). Air valve (5) will come free.6. Remove bolt (3) and the washer from manifold (2). The electrical wiring harness clip will come free. Remove manifold (2) from the machine. 7. Remove nut (10) and hard washer (9) that hold solenoid (8) to manifold (2).8. Remove solenoid (8) from manifold (2). 9. Remove cartridge assembly (11) from manifold (2). 10. Remove back-up ring (18) and O-ring seal (15) from cartridge assembly (11).11. Remove back-up ring (17) and O-ring seal (14) from cartridge assembly (11).12. Remove O-ring seal (16) and back-up ring (13) from cartridge assembly (11).13. Remove O-ring seal (12) from cartridge assembly (11).Install Centershift Lock Control Valve
1. During the installation of the Centershift lock control valve, check the condition of all the O-ring seals and back-up rings that are used in the assembly. If any of these components are damaged, use new parts for replacement. 2. Install O-ring seal (12) to carriage assembly (11).3. Install back-up ring (13) and O-ring seal (16) to carriage assembly (11).4. Install O-ring seal (14) and back-up ring (17) to carriage assembly (11).5. Install O-ring seal (15) and back-up ring