Does the John Deere 6675 Skid Steer Have a Fuel Primer

[MikePhua]

Overview of the John Deere 6675
The John Deere 6675 skid steer loader was part of Deere’s 6000-series compact equipment line introduced in the 1990s. Designed for versatility and durability, the 6675 featured a Yanmar diesel engine, hydrostatic transmission, and a rated operating capacity of approximately 1,750 pounds. It was widely used in agriculture, landscaping, and light construction, praised for its maneuverability and straightforward mechanical layout.
Unlike newer models with electronic fuel systems, the 6675 retained a mechanical fuel delivery system, which included a lift pump and inline filters. This simplicity made it easier to maintain but also meant that cold starts and fuel system priming required more attention.
Fuel System Configuration and Priming
The 6675 does not have a traditional bulb-style fuel primer. Instead, it relies on an electric lift pump mounted near the fuel filter assembly. This pump is responsible for drawing fuel from the tank and supplying it to the injection pump. When the ignition key is turned on, the lift pump activates and begins pressurizing the system.
Some models may include a manual priming lever located on the fuel filter block, especially if retrofitted or if the engine shares components with similar New Holland or Ford units. This lever can be used to manually prime the system after a fuel filter change or if the machine has run dry. However, not all 6675 units have this feature, and its presence may depend on the engine variant or aftermarket modifications.
Cold Start Challenges and Diagnostic Considerations
Owners have reported that the 6675 can be difficult to start in cold weather, often requiring multiple attempts before the engine runs smoothly. This behavior may be caused by:

• Weak electric lift pump, failing to maintain adequate pressure
  
• Air leaks in fuel lines, especially at hose clamps or filter housings
  
• Faulty glow plugs or intake heater, reducing combustion efficiency during cold starts
  
• Fuel filter restrictions, including wax buildup or debris in the inline screen
  

To diagnose the issue:

• Listen for the lift pump when the key is turned on. A faint humming sound indicates it’s working.
  
• Inspect the inline metal or plastic fuel filter. Ensure it’s rated for diesel and not a gasoline substitute.
  
• Check the small brass block near the pump inlet for a fine mesh screen. Clean out any debris.
  
• Test glow plugs using an ohmmeter. Resistance should be consistent across all units.
  
• Use synthetic oil in winter to reduce engine drag and improve cold cranking.
  

Maintenance Tips and Long-Term Solutions
To improve reliability and reduce wear on the starter motor:

• Let the lift pump run for 30–60 seconds before cranking, especially after filter changes or long storage.
  
• Replace the inline filter every 50–100 hours. Choose a clear plastic version with a fine element for better filtration.
  
• Check electrical connections to the lift pump and glow plug circuit. Corrosion or loose terminals can cause intermittent failures.
  
• Consider installing a block heater or using a diesel-fired torpedo heater in extreme cold.
  

One operator in Minnesota reported that after replacing a faulty lift pump and switching to synthetic oil, his 6675 started reliably even in subzero conditions. He also added a manual preheat button to extend glow plug activation beyond the default cycle.
Conclusion
The John Deere 6675 does not universally include a manual fuel primer, but it does rely on an electric lift pump for fuel delivery. Cold start issues are often related to fuel pressure, air leaks, or glow plug performance rather than the absence of a primer. With proper maintenance and a few strategic upgrades, the 6675 can remain a dependable workhorse in all seasons.