ROLLER 1541221 - Caterpillar

At operating temperature, the hydraulic oil is hot and under pressure. Hot oil can cause burns. To prevent possible personal injury, release the pressure in the implement hydraulic circuits (boom, stick and bucket) before any hydraulic lines or components are disconnected or removed.
1. Release the pressure in the hydraulic system as follows: a. Lower the blade to the ground.b. Fully retract the rod in the stick cylinder.c. Adjust the position of the bucket so it will be flat on the ground when the boom is lowered.d. Lower the boom until the bucket is flat on the ground.e. Shut off the engine, and put the hydraulic activation control lever in the "Lock" position.f. Move the control levers for the boom, bucket, stick and swing through their full travel strokes. This will relieve any pressure that may be present in the pilot system.g. Slowly loosen the Fill/Vent plug on the hydraulic oil tank to release the pressure.h. Tighten the Fill/Vent plug on the hydraulic oil tank.i. The pressure in the hydraulic system has now been released. Lines and components can now be removed. 2. Disconnect wiring harness (2).3. Disconnect three hose assemblies (1) from the two-speed solenoid valve.4. Remove the two bolts and washers that hold two-speed solenoid valve (3) to the mounting bracket located behind the pilot manifold. Remove the two-speed solenoid valve. Install the two-speed solenoid valve in the reverse order of removal.5. Check the oil level in the hydraulic oil tank. Fill the hydraulic oil tank with oil to the correct level. See the Operation & Maintenance Manual for the correct filling procedure.Disassemble & Assemble Two-Speed Solenoid Valve
Start By:a. remove two-speed solenoid valve1. Be sure the outside of the two-speed solenoid valve is clean and free of dirt and debris prior to disassembly. 2. Remove two socket head bolts (1) and solenoid (2). 3. Remove fittings (4) from the valve body. Remove the O-ring seal from the fittings. 4. Remove plug (9) and the O-ring seal from valve body (5). Remove O-ring seal (8), spring (7) and spool (6) from the valve body (5). Assemble the proportional reducing valve in the reverse order of disassembly. Prior to assembling the proportional reducing valve, be sure all parts are clean and free of dirt and debris. Put clean hydraulic oil on the internal parts of the valve. Also, check the condition of the O-ring seals. If the seals are damaged, use new parts for replacement. During assembly, tighten plug (9) to a torque of 20 2 N m (15 1 lb ft). Tighten two socket head bolts (1) to a torque of 6 1 N m (4 1 lb ft).End By:a. install two-speed solenoid valve