Electric Fuel Pump Replacement on John Deere CT332

[MikePhua]

Background
The John Deere CT332 multi-terrain loader originally uses a manual lift fuel pump responsible for pulling diesel fuel from the tank and supplying it to the engine injection system. Some operators consider replacing the manual pump with an electric fuel pump, such as those manufactured by FACET, to improve fuel delivery or simplify maintenance.
Fuel Pressure Specifications
When selecting and installing an electric fuel pump, it is essential to maintain the correct pressure that matches engine requirements and pump specifications. Typical pressure for an electric diesel fuel pump for loaders like the CT332 should be low pressure, roughly in the 5 to 15 PSI range, sufficient to supply fuel without overpressurizing the lift pump circuit. Excessive pressure risks damaging fuel lines, seals, or fuel injectors.
Installation Challenges

• The CT332 engine and fuel system were designed with a manual lift pump integrated into hard-to-access locations, often requiring engine removal to service. This design complicates retrofit or replacement with electric pumps.
  
• Routing fuel lines, electrical wiring, and securing pump mounts must be carefully planned to avoid interference with existing components or hazards.
  
• The original wiring diagram shows the pump powered by a yellow wire connected through the glow plug module, which may be cut or modified in previous repairs.
  

Operating Observations

• It is possible for the engine to run without power to an electric lift pump if the manual pump and injection pump can generate enough vacuum to draw fuel, but power loss incidents or brief fuel starvation may occur in some conditions.
  
• Loss of power or engine hesitations during heavy usage or cold starts may indicate issues with the lift pump or fuel delivery system.
  

Recommendations

• Select a FACET or equivalent electric fuel pump rated for diesel fuel and continuous operation at approximately 12V (matching the loader’s electrical system).
  
• Confirm or measure required pressure and flow on the original manual lift pump before selecting a replacement. Most FACET pumps list pump curves helpful for matching applications.
  
• Carefully install electrical connections following manufacturer wiring diagrams, ensuring secure grounds and fused power circuits.
  
• Test the system for leaks and proper fuel flow before full operation.
  
• When in doubt, consult John Deere or authorized dealers for guidance to avoid fuel system damage.
  

Glossary

• Manual Lift Pump: A mechanically driven fuel pump pulling fuel from the tank for injection.
  
• Electric Fuel Pump: An electrically powered pump providing fuel flow independent of engine speed.
  
• Lift Pump Circuit: The lower pressure portion of the fuel system supplying fuel to the injection pump.
  
• Glow Plug Module: Electrical module controlling glow plugs and sometimes auxiliary electrical components like fuel pumps.
  
• Pump Pressure: Force applied by the fuel pump to move fuel through the fuel system.
  

Summary
Replacing the manual lift fuel pump on a John Deere CT332 with an electric FACET pump is feasible but requires attention to fuel pressure specifications, electrical integration, and system compatibility. Proper pressure matching and installation safeguards fuel system components and engine performance. Consultation of original wiring schematics and pump performance curves ensures a successful upgrade or repair, enhancing reliability in the field.