Coolant System Service and Radiator Flushing on the Caterpillar 246C Skid Steer

[MikePhua]

The 246C and Its Cooling System Design
The Caterpillar 246C skid steer loader, introduced in the late 2000s, was part of Cat’s C-series compact equipment lineup. Designed for high-performance applications in construction, landscaping, and municipal work, the 246C featured a turbocharged diesel engine, pilot-operated joystick controls, and a pressurized cooling system engineered for durability in dusty and high-load environments.
With a rated operating capacity of approximately 2,000 lbs and a net power output near 74 hp, the 246C became a popular choice for contractors needing a balance of power and maneuverability. Its cooling system includes a radiator, oil cooler, thermostat, water pump, and expansion tank, all integrated to maintain optimal engine temperature under variable load conditions.
Terminology Annotation
- Radiator Flush: The process of removing old coolant and internal deposits from the radiator and cooling passages using water, chemical agents, or compressed air.
- Thermostat Housing: The component that holds the thermostat and regulates coolant flow based on engine temperature.
- Coolant Reservoir: A pressurized overflow tank that stores excess coolant and allows for thermal expansion.
- Backflushing: A method of cleaning the cooling system by reversing fluid flow to dislodge sediment and scale.
When and Why to Flush the Cooling System
Routine coolant replacement is essential for preventing corrosion, overheating, and premature wear of engine components. While Caterpillar recommends coolant changes every 2,000 hours or two years, flushing is typically reserved for specific conditions:

• After an oil cooler failure that contaminates the coolant
  
• When switching coolant types (e.g., from conventional to extended-life)
  
• If overheating persists despite proper coolant levels
  
• When sediment buildup is visible in the reservoir or radiator fins
  

In most cases, draining and refilling the coolant is sufficient. However, backflushing may be necessary if the system shows signs of blockage or contamination.
A Story from the Olympic Peninsula
In Port Townsend, Washington, a contractor operating a 246C noticed rising engine temperatures during prolonged grading work. Suspecting a clogged radiator, he attempted a flush using a garden hose. After removing the thermostat and disconnecting the lower radiator hose, he flushed the system until clear water emerged. The machine returned to normal operating temperature, and he later installed a new thermostat and refilled with Cat ELC coolant. The issue did not recur.
Recommended Procedure for Radiator Flushing
To flush the cooling system on a 246C:

• Allow the engine to cool completely
  
• Remove the radiator cap and drain plug to empty the coolant
  
• Disconnect the lower radiator hose and thermostat housing
  
• Use a low-pressure hose to flush water through the system in reverse
  
• Inspect for debris, oil residue, or scale
  
• Reinstall the thermostat and hoses
  
• Fill with approved coolant (e.g., Cat ELC or equivalent)
  
• Run the engine and monitor temperature and coolant level
  
• Top off the reservoir after thermal cycling
  

If contamination is severe, consider using a chemical flush agent compatible with aluminum and diesel cooling systems. Always follow with a thorough rinse to prevent residual chemical damage.
Preventative Maintenance and Coolant Health
To maintain cooling system integrity:

• Check coolant level weekly and inspect for discoloration or oil sheen
  
• Replace coolant every 2,000 hours or per manufacturer recommendation
  
• Inspect radiator fins for dust and debris; clean with compressed air
  
• Test coolant pH and freeze point annually
  
• Replace the thermostat every 3,000 hours or during major service
  
• Monitor engine temperature via onboard diagnostics or infrared thermometer
  

For machines operating in extreme climates, consider installing a coolant heater or upgrading to extended-life coolant with organic acid technology.
Conclusion
Flushing the radiator and coolant system on the Caterpillar 246C is a straightforward but critical maintenance task that ensures thermal stability and engine longevity. While full flushing is not always necessary, understanding when and how to perform it can prevent costly downtime and component failure. With proper technique and attention to coolant health, the 246C remains a dependable asset in compact earthmoving operations.