PC220-7 Right Track Slow: Diagnosis and Solutions

[MikePhua]

Introduction to the PC220-7 Track Issue
The Komatsu PC220-7 is a well-regarded hydraulic excavator used for various heavy-duty tasks. However, like any complex machinery, it can face operational issues that affect its performance. One such problem reported by some users is a slow-moving right track, which can significantly affect the machine's overall productivity and efficiency. In this article, we explore the causes behind a slow-moving right track, how to diagnose the issue, and the steps you can take to resolve it.
Common Causes of a Slow Right Track

1. Hydraulic System Issues
   Hydraulic problems are among the most common reasons for a slow track on the PC220-7. The track's movement relies on the hydraulic system, so any issues with fluid flow or pressure can lead to slower response times.
   • Possible Causes:
     • Clogged hydraulic filters or lines.
       
     • Low hydraulic fluid levels or contaminated fluid.
       
     • Faulty hydraulic pumps or valves.
       
   • Solutions:
     • Inspect the hydraulic fluid levels and ensure they are within the recommended range. Replace any contaminated fluid.
       
     • Check the hydraulic filters and lines for clogs and clean or replace them as needed.
       
     • If the pump or valve is malfunctioning, they may need to be repaired or replaced by a professional.
       
2. Track Motor or Drive Motor Problems
   The track drive motors are responsible for powering the tracks. A malfunctioning motor can cause one track to move slower than the other, leading to uneven track performance.
   • Possible Causes:
     • Worn-out or damaged drive motor.
       
     • Issues with the motor’s internal components, such as the pistons or seals.
       
   • Solutions:
     • Inspect the drive motor for any visible damage or signs of wear. If the motor is faulty, it will need to be replaced.
       
     • Perform a pressure test on the track motor to check for internal leakage or failure.
       
3. Final Drive Issues
   The final drive unit transfers power from the drive motor to the track itself. If there are issues within the final drive, it can cause one track to lag or operate more slowly than the other.
   • Possible Causes:
     • Low or contaminated gear oil.
       
     • Worn-out gears, bearings, or seals in the final drive.
       
   • Solutions:
     • Check the gear oil in the final drive and replace it if it’s low or contaminated.
       
     • Inspect the final drive components, such as the gears, bearings, and seals, for any signs of damage. Replace any worn parts to restore proper functionality.
       
4. Track Tension Problems
   Improper track tension can cause a slow-moving track. If one track is too tight or too loose, it may not move as efficiently, leading to slower operation on that side.
   • Possible Causes:
     • Incorrect tensioning of the track.
       
     • Uneven wear or damage to the track.
       
   • Solutions:
     • Check the track tension using the manufacturer’s recommended procedure. Adjust the tension to the correct level to ensure smooth operation.
       
     • Inspect the track for wear or damage and replace it if necessary.
       
5. Electrical System Issues
   Electrical problems can also contribute to slower track movement, especially if there are faults in the system that controls the hydraulic or drive motors.
   • Possible Causes:
     • Faulty sensors or wiring issues.
       
     • Malfunctioning relays or controllers.
       
   • Solutions:
     • Inspect the electrical system for any loose or corroded connections.
       
     • Test the sensors and relays to ensure they are functioning properly. If any components are faulty, they may need to be replaced.
       
6. Uneven Ground or Obstructions
   Sometimes the issue may not be with the machine itself, but with the conditions in which it is being operated. Uneven or soft ground can cause one track to perform slower than the other.
   • Possible Causes:
     • Soft or uneven terrain.
       
     • Obstructions preventing the track from moving freely.
       
   • Solutions:
     • Evaluate the ground conditions and try to avoid operating on soft or uneven surfaces that may hinder the track's movement.
       
     • Check for any debris or obstructions around the track that may be causing resistance.
       

Steps for Diagnosing the Slow Track Issue

1. Check the Hydraulic System:
   Start by checking the hydraulic fluid levels and the condition of the filters. Look for any signs of leaks or contamination in the hydraulic system that could be affecting the track's speed.
   
2. Inspect the Track Motor and Final Drive:
   Look for any visible damage or wear in the drive motor and final drive system. Perform a pressure test to check the motor’s functionality and inspect the gear oil levels.
   
3. Verify Track Tension:
   Ensure that both tracks are properly tensioned according to the manufacturer’s specifications. Adjust the tension if necessary and inspect the track for wear or damage.
   
4. Examine the Electrical System:
   Inspect the wiring, sensors, and electrical components for any issues. Test relays and controllers to ensure they are working correctly.
   
5. Evaluate Operating Conditions:
   Consider the terrain where the machine is being used. If the ground is uneven or soft, it could be contributing to the slower track movement. Also, check for any obstructions that may be preventing the track from moving freely.
   

Conclusion
A slow-moving right track on the Komatsu PC220-7 can be caused by a variety of issues, ranging from hydraulic system problems to track tension or motor malfunctions. By following a methodical troubleshooting approach, operators can identify the root cause and take appropriate corrective actions. Regular maintenance, including checking fluid levels, inspecting key components like the track motor and final drive, and ensuring proper track tension, can help prevent these issues from arising in the future. If the problem persists after troubleshooting, it may be necessary to consult a professional mechanic for further assistance.