Komatsu PC120-6 Troubleshooting and Maintenance Guide

[MikePhua]

Introduction to Komatsu PC120-6
The Komatsu PC120-6 is a mid-sized hydraulic excavator commonly used in construction, mining, and earthmoving applications. Known for its durability and efficiency, this machine is equipped with a robust engine and powerful hydraulic system. However, like any heavy machinery, it can face operational challenges over time. This guide discusses common issues faced by PC120-6 operators and provides troubleshooting and maintenance tips to keep the machine in peak condition.
Common Issues with Komatsu PC120-6

1. Hydraulic System Failures
   Hydraulic issues are one of the most frequent problems reported by Komatsu PC120-6 users. Symptoms include slow movement of the boom, bucket, or arm, or a complete failure of hydraulic functions. The root causes can include low hydraulic fluid levels, dirty filters, air in the system, or even a failing hydraulic pump. Addressing these issues promptly is essential to avoid costly repairs.
   
2. Engine Starting Problems
   Some users report difficulty starting the engine, especially in colder weather. Common causes for this include weak batteries, clogged fuel filters, or issues with the fuel injectors. Additionally, a malfunctioning starter motor or worn-out glow plugs can lead to poor engine performance during start-up.
   
3. Undercarriage Wear
   The undercarriage of the PC120-6, consisting of the tracks, rollers, and sprockets, is subject to significant wear due to the constant friction and stress during operation. Over time, this can lead to track slippage, excessive noise, or difficulty in maintaining traction. Regular inspection and maintenance of the undercarriage are crucial to ensure optimal performance.
   
4. Electrical Issues
   Electrical problems, including issues with the control panel or sensors, are also common in the PC120-6. These can manifest as error codes, intermittent operation of machine components, or complete shutdowns. Often, these problems are caused by faulty wiring, sensors, or damaged fuses. Identifying and fixing electrical issues promptly is essential for the overall health of the machine.
   

Troubleshooting Tips

1. Inspect Hydraulic System
   To resolve hydraulic issues, start by checking the fluid level. If it's low, top it up with the recommended hydraulic fluid. Also, inspect the hydraulic filters for dirt or blockages, as these can restrict fluid flow. If problems persist, check for leaks in the hoses or connections and ensure there is no air trapped in the system.
   
2. Engine Maintenance
   If the engine is having starting issues, check the battery for charge and condition. Replace any corroded or weak batteries. If the battery is in good shape, inspect the starter motor and glow plugs for wear or malfunction. Additionally, check the fuel system for clogged filters and inspect the fuel injectors for proper function. Air in the fuel lines can also prevent proper starting, so bleed the fuel system if needed.
   
3. Undercarriage Inspection
   Regularly inspect the tracks, rollers, and sprockets for signs of wear or damage. Check for uneven track tension or slack, and adjust accordingly. Lubricate the undercarriage components regularly to prevent excessive wear. If the tracks show signs of significant damage or wear, it may be necessary to replace them to ensure the machine operates efficiently.
   
4. Electrical System Diagnostics
   If the electrical system is malfunctioning, begin by checking the control panel for any error codes. Follow the diagnostic codes to identify the faulty components. Inspect the wiring for any visible damage or wear. In some cases, cleaning or replacing faulty sensors, fuses, or relays can resolve the issue.
   

Preventive Maintenance Tips

1. Regular Fluid Checks
   Regularly check the engine oil, hydraulic fluid, and coolant levels to ensure they are within the recommended ranges. Low or dirty fluids can cause engine or hydraulic issues, leading to breakdowns. Use only the recommended fluids to ensure the machine’s longevity.
   
2. Track and Undercarriage Care
   The undercarriage should be cleaned regularly to remove dirt and debris that can cause wear. Perform regular inspections for cracks or damage to tracks, rollers, and sprockets. Replace any worn or damaged components to prevent further issues.
   
3. Clean the Air Filters
   Clogged air filters can cause the engine to run inefficiently, reducing performance and fuel economy. Clean or replace the air filters regularly, especially if the machine is used in dusty or dirty environments.
   
4. Electrical System Inspection
   Conduct routine checks of the electrical wiring and sensors. Ensure that all components are properly connected and that there are no signs of wear or corrosion. Regular electrical inspections can prevent unexpected breakdowns.
   

Conclusion
The Komatsu PC120-6 is a reliable and powerful excavator, but like all machines, it requires regular maintenance to perform at its best. By addressing common issues such as hydraulic failures, engine starting problems, undercarriage wear, and electrical faults, operators can keep the PC120-6 running smoothly. Regular inspections and preventive maintenance will help extend the life of the machine and reduce the risk of costly repairs. Proper care and attention to detail are key to ensuring the PC120-6 continues to deliver exceptional performance in demanding work environments.