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How to Cool Down an Overheating Concrete Pump Truck

Jun. 22, 2026

1. Common Causes of High Coolant Water Temperature

The thermostat gets stuck closed, forcing coolant to only run through the small circulation loop without passing the radiator.
The radiator is clogged with dirt and scale, restricting coolant flow. A temperature gun can be used to test the temperature difference between the top and bottom of the radiator; the bottom will show a much lower temperature if clogged.
Insufficient fan rotating speed caused by a faulty fan clutch.
Damaged or missing sealing rubber strips around the radiator. This creates air eddies and hot air recirculation, completely crippling the cooling effect.
Easily overlooked false alarms: defective temperature sensors. The vehicle ECU only reads abnormal data rather than reflecting the engine’s actual operating temperature.

2. Direct Hazards of Excessively High Oil Temperature to the Engine

Engine overheating means both engine oil temperature and coolant temperature exceed 90℃. Due to thermal expansion and contraction, rising temperatures narrow internal clearances of engine components, triggering severe abrasion or cylinder scoring.

If heat generated by excessive wear surpasses the heat dissipation capacity, bearing shells will heat up rapidly. Once the local temperature hits the melting point of lead, lead and copper alloys inside the bearing shells melt. This eventually leads to severe ablation of the crankshaft and bearings, or the critical failure known as bearing seizure, resulting in catastrophic losses.

Therefore, when both oil and coolant temperatures spike, priority must be given to lowering the oil temperature first.

How to Cool Down an Overheating Concrete Pump Truck

3. Reducing Oil Temperature Alleviates Rising Coolant Temperature

The radiator is designed to dissipate heat for the engine oil. The standard cooling method is to reduce load and maintain low engine speed.

Under this operating mode, coolant stays longer in contact with high-temperature components for sufficient heat exchange despite slower flow. Meanwhile, reduced load and rotating speed cut down friction heat generated by all moving parts.

Lowering oil temperature not only reduces total heat output of the engine, but also indirectly reduces heat absorbed by coolant, slowing the rise of coolant temperature fundamentally.

The troubleshooting logic for high oil temperature is similar to that of high coolant temperature, with separate large and small circulation loops. The key difference is that the oil circuit relies on an oil return check valve instead of a thermostat. A stuck check valve will cause oil overheating, while other failure causes are identical to those for coolant overheating.

When both engine oil and coolant temperatures are too high with adequate or slightly insufficient fluid levels, always cool the oil first then the coolant. This sequence is not determined by the relative cost of engine oil and coolant.

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