Changing Fuel Filters on the John Deere 120C Excavator

[MikePhua]

The John Deere 120C is a versatile and durable machine widely used in construction and excavation projects. Regular maintenance is crucial to ensure optimal performance and longevity. One of the essential maintenance tasks is changing the fuel filters, which play a vital role in preventing contaminants from reaching the engine.
Understanding the Fuel Filter System
The 120C excavator is equipped with a two-stage fuel filtration system:

• Primary Fuel Filter: This filter captures larger particles and debris from the fuel before it enters the secondary filter.
  
• Secondary Fuel Filter: This filter provides finer filtration, ensuring that any remaining contaminants are removed before the fuel reaches the engine.
  

Both filters are designed to protect the engine's fuel system components, such as the fuel injectors and injection pump, from damage caused by impurities.
Recommended Service Intervals
According to John Deere's maintenance guidelines, the fuel filters should be replaced at the following intervals:

• Every 500 hours of operation: This is the standard replacement interval for both primary and secondary fuel filters.
  
• After running out of fuel: If the machine runs out of fuel, it's advisable to replace the filters immediately, as sediment and water from the bottom of the fuel tank can clog the filters.
  

Procedure for Replacing Fuel Filters

1. Preparation: Ensure the machine is on a level surface and the engine is turned off.
   
2. Locate the Fuel Filters: The primary and secondary fuel filters are typically located near the fuel tank and engine. Refer to the machine's service manual for exact locations.
   
3. Relieve Fuel Pressure: Before removing the filters, relieve any residual fuel pressure to prevent fuel spillage.
   
4. Remove the Old Filters: Use appropriate tools to loosen and remove the old filters. Be prepared for some fuel spillage during this process.
   
5. Install the New Filters: Lubricate the rubber seals of the new filters with clean fuel to ensure a proper seal. Install the new filters by hand-tightening them.
   
6. Prime the Fuel System: After installing the new filters, prime the fuel system to remove air. This can be done by operating the manual priming lever on the lift pump.
   
7. Check for Leaks: Start the engine and check for any fuel leaks around the new filters. Tighten the filters if necessary.
   

Common Issues and Troubleshooting

• Fuel Leaks: If fuel leaks occur after filter replacement, ensure that the filters are properly tightened and that the rubber seals are intact.
  
• Engine Stalling: If the engine stalls shortly after filter replacement, air may still be present in the fuel system. Continue priming the system until the engine runs smoothly.
  
• Difficulty in Removing Filters: If the filters are difficult to remove, use an oil filter wrench to gain better leverage.
  

Importance of Regular Maintenance
Regularly replacing the fuel filters on the John Deere 120C excavator is essential for maintaining engine performance and preventing costly repairs. Neglecting this maintenance task can lead to clogged injectors, reduced fuel efficiency, and potential engine damage.
Conclusion
Changing the fuel filters on the John Deere 120C excavator is a straightforward maintenance task that can be performed with basic tools and knowledge. By adhering to the recommended service intervals and following proper procedures, operators can ensure the longevity and reliability of their equipment.