CASE & PARTS GP-PLANETARY 6T3923 - Caterpillar

To prevent possible personal injury, make sure all cushion hitch components are completely lowered, the pressure from the hydraulic system is released and the engine has been shut off for a minimum of five minutes to be sure that the accumulator oil pressure is zero. The accumulator is filled with dry nitrogen. Do not loosen or remove the valve from the cap on top of the accumulator. A bleed screw at the bottom of the accumulator can be used to release any pressure that remains in the system.
At operating temperature, the hydraulic oil tank is hot and under pressure. Hot oil can cause burns. To prevent possible personal injury, release the pressure in the hydraulic system before any hydraulic lines or components are disconnected or removed.
Release the pressure in the hydraulic system as follows:a. Shut off the engine.b. Move the control levers through their full travel strokes. This will relieve any pressure that may be present in the pilot system.c. Slowly loosen the air breather cap on the hydraulic oil tank to release the pressure.d. Tighten the air breather cap on the hydraulic oil tank.e. The pressure in the hydraulic system has now been released. Lines and components can now be removed. 1. Disconnect five lines and tube assemblies (3).2. Remove four bolts (4) and the clamp holding tube assemblies (7) in place. Position tube assemblies out of the way.3. Disconnect the wire from solenoid (1).4. Disconnect linkage (5) at the control valve.5. Remove four mounting bolts, washers and nuts (6) and control valve (2). Install in the reverse order. Refer to the topic "Lubricant Viscosities and Refill Capacities" in the Operation and Maintenance Manual and fill the hydraulic system with hydraulic fluid.Disassemble Cushion Hitch Control Valve
Start By:a. remove cushion hitch control valve 1. Remove nut (1), solenoid coil (2) and the solenoid valve. 2. Remove O-ring seal, two O-rings and backup rings (4) from solenoid valve (3).3. Remove four bolts (5) and valve body (6). 4. Remove plug (7) from each end of valve body and disassemble the valve. 5. Check O-ring (8) on both plugs (7) and replace if damaged.6. Remove three small O-rings (9) and two large O-rings (10).7. Remove spring (11) and spool (12) from the valve body. 8. Remove retaining ring (13) and seal (14) if necessary.9. Remove two bolts (15), end plate (16) and disassemble valve. 10. Spool (17), spring (18) and spring (19).11. Check O-ring seal (20) and replace if necessary. 12. Remove detent plug (22) from each side and remove spool (21). 13. Check the O-ring seal on detent plugs (22) and replace if necessary.14. Remove bolt and washer (23) if necessary.15. Remove fitting (24). Use Tool (A) to remove the retaining ring, spacer and check valve behind the fitting. 16. Remove the O-ring and backup ring from check valve (25). Spacer (26) and retaining ring (27).Assemble Cushion Hitch Control Valve
Clean all components of the cushion hitch leveling valve and make any replacements if necessary. 1. Install the O-ring and