Excavator Overheating: Why Your Sub-Tank Isn't Pulling Coolant Back
Is your excavator overheating during the summer? One common issue is that the coolant sub-tank fails to pull coolant back, leading to a low water level in the main radiator and eventually engine overheating.
How the Cooling System Works
When the engine runs, the coolant heats up and expands. The excess coolant is pushed through the hose into the sub-tank. Once the engine cools down, a vacuum is created, and the coolant should naturally be drawn back into the main radiator.
Common Causes for Failure
If the water isn't returning, check these three areas:
Radiator Filler Neck Deformation: The seal might not be tight enough.
Faulty Radiator Cap: The cap's springs or seals might be damaged or rusted, preventing proper vacuum pressure.
Combustion Chamber Leakage: Exhaust gases from the engine might be leaking into the water jacket, increasing pressure in the main radiator.
Troubleshooting Checklist
Inspect the Filler Neck: Check for any deformation where the cap attaches.
Check for External Leaks: Look for water dripping around the cap area.
Examine the Radiator Cap: If the springs are rusted or the cap is stuck, it needs to be replaced.
Start the Engine: Observe the main radiator. If you see continuous bubbles, it indicates a head gasket or cooler failure.
