KIT-PISTON RING 2886545 - 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.
1. Release the pressure in the hydraulic system as follows: a. Fully retract the rod in the stick cylinder.b. Adjust the position of the bucket so it will be flat on the ground when the boom is lowered.c. Lower the boom until the bucket is flat on the ground.d. Shut off the engine, and put the hydraulic activation control lever in the "Lock" position.e. 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.f. Slowly loosen the air breather cap on the hydraulic oil tank to release the pressure.g. Tighten the air breather cap on the hydraulic oil tank.h. The pressure in the hydraulic system has now been released. Lines and components can now be removed. 2. Disconnect wiring harness (1).3. Remove two socket head bolts (2) that hold solenoid valve (3) to the pilot manifold. Remove the solenoid valve. Remove the two O-ring seals from the body of the valve. Install the solenoid valve in the reverse order of removal. Prior to installing the valve, check the condition of the two O-ring seals used in the valve body. If the seals are worn or damaged, use new parts for replacement. Tighten socket the two socket head bolts that hold the solenoid valve to a torque of 9 1 N m (7 1 lb ft).4. Check the oil level in the hydraulic oil tank. Fill the hydraulic oil tank to the correct level. See the Operation & Maintenance Manual for the correct filling procedure.