LEVER 6S4793 - Caterpillar

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 implement hydraulic circuits (boom, stick and bucket) before any hydraulic lines or components are disconnected or removed.
2. Release the pressure in the implement hydraulic circuits (boom, stick, and bucket) before any hydraulic lines or components are disconnected or removed. Release the pressure as follows:a. Shut off the engine and place key in the ON position. Put the hydraulic activation control lever in the UNLOCK position.b. Move the control levers for boom, stick and swing to all full stroke positions. This will release any pressure that might be present in the pilot system.c. Return the key to OFF position.d. Slowly loosen the fill plug on the hydraulic tank and release the pressure.e. Tighten the fill plug on the hydraulic tank.f. The pressure in the hydraulic system has been released and lines and components can be removed. The removal and installation procedure for the fine control solenoid valve, the travel speed solenoid valve and the swing priority solenoid valve is the same. In the procedure which follows, the fine control solenoid valve is removed and installed. 3. Oil will drain from the pilot manifold when the solenoid valve is removed. Place a drain pan under the pilot manifold to contain the drain oil.4. Disconnect wiring harness (2) from solenoid valve (1). Remove two bolts (3) and solenoid valve (1) from the pilot manifold. 5. Remove four O-ring seals (4) from the solenoid valve. The following steps are for the installation of the solenoid valves.6. Check the condition of four O-ring seals (4). If the seals are damaged, use new parts for replacement.7. Install solenoid valve (1) in the reverse order of removal. Tighten two bolts (3) to a torque of 4 .4 N m (3 .3 lb ft).8. Fill the hydraulic oil tank with oil to the correct level. Refer to the Operation & Maintenance Manual for the correct filling procedure.