HOSE AS 4892751 - 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 and 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.
View From Under Cab2. Remove seven bolts (1), the washers and spacers that hold access cover (2) in place. Remove the access cover from under the front of the cab.
View From Under Cab3. Put identification marks on four hose assemblies (3) that are connected to the pilot control valve (travel) so they can be reinstalled in their original locations. Disconnect the four hose assemblies from the valve. Put plugs in the hose assemblies to prevent oil loss and to keep dirt and debris out of the hydraulic system.4. Disconnect spring assembly (4) from the pilot control valve (travel). 5. Remove the rubber floor mate from the cab to gain access to the pilot control valve (travel).6. Remove two bolts (5) and the washers that hold pilot control valve (travel) (6) to the cab floor. Remove the pilot control valve (travel). The following steps are for the installation of the pilot control valve (travel)7. Put pilot control valve (travel) (6) in position in the cab floor. Install the two washers and bolts (5) that hold it. Reinstall the rubber floor mate in the cab.8. Connect spring assembly (4) and four hose assemblies (3) to the pilot control valve (travel).9. Reinstall access cover (2) under the cab.10. 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 Pilot Control Valves (Travel)
Start By:a. remove pilot control valves (travel)
Do not mix the components in the pilot control valve (travel) as it is being disassembled. All components should be reinstalled in their original locations. Put identification marks on all components to prevent mixing.
1. Make sure the outside of the pilot control valve (travel) is thoroughly clean prior to disassembly. Check the condition of all O-ring seals used in the valve. If the seals are worn or damaged, use new parts for replacement. 2.