TUBE ASSEM. 4N5002 - Caterpillar

Warnings
Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine.To prevent possible injury, perform the procedure that follows before testing and adjusting the power train.
Hot hydraulic oil under high pressure can remain in the components of the hydraulic system or the power train system after the engine has been stopped. The uncontrolled release of the hydraulic oil can cause sudden machine movement and can also result in the following conditions:
Burns
The penetration of body tissue
Other personal injury
DeathIf hydraulic oil penetrates body tissue, the injury must be treated immediately by a doctor who is familiar with this type of injury. Use a board or a piece of cardboard to check for a hydraulic oil leak. Make sure that all of the attachments have been lowered to the ground and that all trapped pressure has been released from the hydraulic system and the power train system. Also, make sure that the hydraulic oil is cool before the removal of any components or lines. Remove the hydraulic oil filler cap only when the engine is stopped and the filler cap is cool enough to touch with your bare hand.
Personal injury or death can result from not engaging the parking brake.Transmission engagement alone will not prevent machine from rolling when the engine is stopped.
Personal injury can result if the machine moves while testing.If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products.Dispose of all fluids according to local regulations and mandates.
General Procedure
Know the Machine.Understand the operation and the interaction of the machine systems. Know if the symptom is a characteristic of normal operation or if the symptom is a problem.Refer to the Systems Operation in your Service Manual.
Identify the Symptom.
Speak with the operator about the symptom.
Ask about the performance of the machine prior to the problem.
Determine the time that the symptom first occurred.
Determine the operating conditions at the time of the problem.
Ask the operator about the sequence of events prior to the failure. Determine the order of the occurrences.
Ask the operator about the steps that have been taken to troubleshoot the machine.
Check the history of repairs of the machine.
Ask about the preventive maintenance of the machine.
Inspect the machine. Look for problems. Notice any unusual odors in the air. Listen for unusual noises.Complete the steps in Troubleshooting, "Visual Inspection".If you complete the visual inspection and the problem is not identified, perform the appropriate tests and/or adjustments in Specifications, Systems Operation/Testing and Adjusting for your machine.
Troubleshoot the faults with the service codes.Determine if the ECM has detected any faults. A service code is used to