Removing the Radiator from a Caterpillar 951C Track Loader

[MikePhua]

The Caterpillar 951C and Its Cooling System Design
The Caterpillar 951C track loader was introduced in the mid-1970s as part of CAT’s evolution in crawler loaders, combining robust mechanical systems with improved operator comfort and hydraulic responsiveness. With an operating weight of approximately 30,000 pounds and powered by a CAT 3304 four-cylinder diesel engine producing around 100 horsepower, the 951C was built for excavation, loading, and site preparation in rugged environments.
The cooling system in the 951C is critical to engine longevity, especially under heavy load or in dusty conditions. The radiator is mounted at the front of the engine compartment, protected by a steel grille and shroud, and connected to the engine via upper and lower coolant hoses. Over time, radiators can become clogged with debris or corroded internally, requiring removal for cleaning, repair, or replacement.
Terminology Clarification

• Radiator Core: The central section of the radiator where coolant flows through tubes and fins for heat dissipation.
  
• Shroud: A protective cover that directs airflow through the radiator and shields the fan.
  
• Coolant Reservoir: A tank that holds excess coolant and allows for thermal expansion.
  
• Fan Assembly: A belt-driven or hydraulic-powered fan that pulls air through the radiator.
  
• Mounting Brackets: Steel supports that secure the radiator to the frame or engine bay.
  

Preparation and Safety Measures
Before beginning radiator removal:

• Park the machine on level ground and allow the engine to cool completely
  
• Disconnect the battery to prevent accidental fan engagement
  
• Drain coolant from the system using the petcock valve or lower hose
  
• Wear gloves and eye protection to avoid contact with hot coolant or sharp edges
  

In one documented case, a forestry crew in Oregon removed the radiator from a 951C after noticing overheating during slope work. The radiator fins were packed with pine needles and dust, and the lower tank had developed a hairline crack. After removal and re-core, the machine returned to full duty with stable operating temperatures.
Step-by-Step Removal Procedure

1. Remove the Engine Hood and Side Panels
   Unbolt the steel covers to expose the radiator and fan assembly. Some models may have hinged panels for easier access.
   
2. Disconnect Coolant Hoses
   Loosen clamps on the upper and lower radiator hoses. Be prepared for residual coolant to spill.
   
3. Detach the Fan Shroud
   Unbolt the shroud from the radiator frame. This may require removing the fan belt or pulley for clearance.
   
4. Unbolt Mounting Brackets
   Locate and remove the bolts securing the radiator to the frame. Use penetrating oil if bolts are rusted.
   
5. Lift the Radiator Out
   Use a hoist or loader boom with chains to carefully lift the radiator. Avoid tilting or twisting to prevent damage to the core.
   
6. Inspect Surrounding Components
   Check the fan blades, water pump, and thermostat housing for wear or leaks. Replace any compromised parts while the radiator is out.
   

Common Challenges and Solutions

• Seized Bolts
  Use heat and penetrating oil. If necessary, cut and replace with new hardware.
  
• Damaged Hose Connections
  Replace with new clamps and reinforced hoses rated for high temperature.
  
• Core Contamination
  Flush the radiator with a high-pressure water stream or chemical cleaner. If internal corrosion is severe, consider a full re-core or replacement.
  
• Fan Clearance Issues
  Some 951C units have tight spacing between the fan and radiator. Removing the fan first may simplify extraction.
  

Preventive Maintenance Recommendations
To extend radiator life:

• Blow out fins weekly with compressed air in dusty environments
  
• Use coolant with anti-corrosion additives
  
• Replace hoses every 1,000 hours or during major service
  
• Inspect for leaks monthly and monitor temperature gauge during operation
  

In 2019, a contractor in Texas implemented a quarterly cooling system inspection across his CAT loader fleet. Over two years, radiator-related failures dropped by 60%, and fuel efficiency improved due to reduced engine strain.
Conclusion
Removing the radiator from a Caterpillar 951C is a manageable task with the right preparation and tools. Whether addressing overheating, leaks, or core blockage, methodical disassembly and inspection can restore cooling performance and prevent engine damage. The 951C remains a durable and serviceable machine, and maintaining its cooling system is key to keeping it productive in demanding conditions.