Pt.2：Heavy Truck Cooling System Failure Analysis & Maintenance Guide for African High-Temp Worksites

After sorting through East African and Southern African fleet maintenance data, more than 80% of chronic overheating problems stem from incorrect maintenance habits rather than component quality issues.

Only Replace Radiator Instead of Full-System Inspection

When overheating occurs, the first reaction is to change the radiator. In fact, 70% of overheating faults come from the thermostat, fan clutch, water pump, or clogged intercooler. Blind radiator replacement cannot solve the root cause and leads to repeated failures.

Using Tap Water or Mixed Coolant

Water contains mineral impurities that form scale at high temperatures. Mixing different coolant formulas causes chemical reactions, leading to precipitation, pipeline blockage, and accelerated component corrosion. This is the main reason for short cooling system service life in African fleets.

Neglecting Intercooler Cleaning

Most fleets only clean the radiator while ignoring the intercooler. A blocked intercooler causes high intake temperature, reduced power, increased exhaust temperature, and indirectly raises engine water temperature. It also aggravates DPF clogging and emission system failures.

No Regular Inspection of Fan Clutch and Water Pump

Fan clutch and water pump wear slowly without obvious warning signs. By the time overheating appears, the components have already suffered severe performance degradation. Regular testing of fan speed and water pump pressure is essential for high-temperature seasons.

Ignoring Air in the Cooling System

After coolant replacement or pipeline maintenance, air remains inside the water channel. Unbleeded air causes poor circulation, local overheating, and cylinder gasket damage. Most African maintenance teams skip the bleeding process.

Combined with local high-temperature, dusty, heavy-load working conditions, we have formulated targeted maintenance standards for HOWO, Shacman, and XCMG heavy trucks.

Daily Inspection

Observe water temperature changes during climbing and heavy load; check coolant liquid level; inspect hoses for leakage; listen for abnormal fan noise; confirm no sudden temperature spikes during operation.

Weekly Maintenance

Blow clean radiator and intercooler surface dust with compressed air; check fan clutch engagement sensitivity; inspect expansion tank pressure and breathing valve status.

Monthly Inspection

Test thermostat opening temperature; check water pump operation stability; inspect cooling hose aging and swelling; drain tiny air bubbles from the system; check for scale precipitation.

Quarterly Maintenance

Fully clean radiator and intercooler internal and external passages; replace aging hoses and sealing rings; test fan clutch speed and slippage rate; replace deteriorated coolant.

Semi-Annual Overhaul

Disassemble and inspect thermostat and water pump; thoroughly clean engine water jacket scale; test cooling system pressure tightness; eliminate hidden leakage points.

The cooling system is the temperature control core of heavy trucks and the most vulnerable system in African high-temperature mine environments. Overheating is never an accidental fault — it is the result of long-term dust accumulation, improper coolant use, aging precision components, and incomplete maintenance.

A well-maintained cooling system maintains stable power, reduces fuel consumption, avoids engine derating, and effectively protects the cylinder block and cylinder gasket from permanent damage. For African fleets operating year-round under heavy-load and high-temperature conditions, standardized cooling system maintenance is the lowest-cost and highest-return investment.