CIRCLE AND BEAM ASSEM. 8D2355 - Caterpillar

Warnings
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.
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 specify each detected fault.Each of the components such as switches and sensors are referenced by a unique CID (component identifier).To read a diagnostic code, refer to Troubleshooting, "Diagnostic Capabilities" in the beginning of this manual.
Troubleshoot using the description of the symptom.If you troubleshoot the service codes and the problem is not resolved, continue troubleshooting using the symptom. Identify the component that is the most probable cause of the symptom.
After the problem is resolved, prepare the machine for operation. Complete a maintenance record for the machine: problem, symptom, and repairs.Refer to the instructions in the Operation and Maintenance Manual for your machine.