Bleeding the Injection Pump on a Case 60XT Skid Steer

[MikePhua]

The Case 60XT and Its Fuel System Design
The Case 60XT skid steer loader was introduced in the early 2000s as part of Case Construction’s mid-frame lineup, designed for versatility in landscaping, light construction, and agricultural work. Powered by a Cummins 4BT diesel engine, the 60XT delivers around 60 horsepower and features a mechanical fuel injection system centered around the Bosch VE rotary pump—a widely used and reliable design across compact equipment.
The Bosch VE pump operates with a lift pump feeding fuel through filters into the injection pump, which then meters and distributes fuel to each injector. While the system is self-bleeding under normal conditions, air intrusion during filter changes or fuel starvation can cause hard starting or complete failure to run.
Terminology Clarification

• Bosch VE Pump: A rotary distributor-type injection pump used in many diesel engines, known for its compact design and mechanical reliability.
  
• Lift Pump: A low-pressure pump that supplies fuel from the tank to the injection pump.
  
• Shutoff Solenoid: An electrically actuated valve that stops fuel flow when the engine is turned off.
  
• Bleeding: The process of removing air from the fuel system to restore proper flow and injection timing.
  
• Cracking Injectors: Loosening the fuel lines at the injector fittings to allow trapped air to escape during cranking.
  

Common Symptoms After Filter Replacement
One of the most frequent issues with the 60XT’s fuel system arises after changing fuel filters. If the system isn’t properly bled, the engine may crank but fail to start, or it may “pop” briefly without catching. This is typically due to air trapped between the filters, pump, and injectors.
In one case, the operator replaced both filters and bled the system at the filter housing until fuel flowed cleanly. However, the engine refused to start. Fuel was present at the injectors and return line, but the machine only sputtered briefly during cranking.
Step-by-Step Bleeding Procedure
To fully purge air from the system and restore starting capability:

• Ensure the fuel shutoff solenoid has power. A missing or disconnected wire will prevent fuel delivery even if the pump is primed.
  
• Use the priming lever on the lift pump to push fuel through the filters. If resistance builds and fuel flows freely, proceed.
  
• Loosen the inlet line at the injection pump (if accessible) and crank the engine or pump manually until fuel squirts out. Tighten the fitting.
  
• Crack open all injector lines at the injectors—not at the pump—and crank the engine. Once fuel and air bubbles escape, tighten each line one at a time.
  
• Avoid loosening the return line unless necessary. On many Cummins setups, the return is tied into the inlet circuit, and opening it can introduce air back into the pump.
  

Electrical Oversight and Solenoid Issues
In one real-world example, the operator discovered that the fuel shutoff solenoid wasn’t receiving voltage. The issue stemmed from a misaligned ROPS bar that interfered with the parking brake switch, cutting power to the solenoid. Although the engine attempted to fire, it couldn’t sustain combustion without fuel flow. Once the solenoid circuit was restored, the machine started immediately.
This highlights the importance of verifying electrical connections during troubleshooting. A weak battery, faulty relay, or misrouted wire can mimic fuel system failure.
Safe Use of Starting Aids
Some operators resort to spraying ether or other volatile compounds into the intake to assist starting. While this can work in emergencies, it carries risks:

• Ether can damage pre-heaters or grid heaters if present.
  
• Overuse can cause detonation and piston damage.
  
• It masks underlying issues that should be resolved properly.
  

If using a spray bottle with diesel or light oil mist, ensure the air filter is removed and the engine is cranked cautiously. Never use starting fluid on engines with active intake heaters.
Recommendations for Reliable Starting
To prevent future starting issues:

• Replace fuel filters with OEM-grade elements and pre-fill them when possible.
  
• Inspect and clean the lift pump annually.
  
• Ensure all fuel lines are tight and free of cracks or leaks.
  
• Test the shutoff solenoid circuit with a multimeter before cranking.
  
• Keep a battery charger on hand during extended cranking to avoid starter damage.
  

For machines with unreliable fuel gauges, consider installing a sight tube or low-fuel warning system to avoid running dry.
Conclusion
Bleeding the injection pump on a Case 60XT requires a methodical approach that addresses both mechanical and electrical components. While the Bosch VE pump is self-bleeding in theory, trapped air between filters and injectors can prevent starting after maintenance. By verifying solenoid power, using the priming lever, and cracking injectors properly, operators can restore fuel flow and get the machine running again. With attention to detail and a few practical checks, even stubborn airlocks can be resolved without resorting to risky shortcuts.