Clean the radiator and aftercooler cores from both sides at every service on dusty sites, check coolant concentration and condition, and test the cap and thermostat at the specified intervals. Most overheating complaints on site equipment are resolved by cleaning and by coolant specification rather than by replacing components.
Service items and intervals
| Item | Interval and action |
|---|---|
| Radiator and aftercooler cores | Clean at every service on dusty sites, more often in severe conditions. Clean from both directions; a one-sided clean leaves the far face blocked. |
| Coolant concentration | Check at intervals. Correct concentration is what protects against both freezing and boiling, and it carries the corrosion inhibitors. |
| Coolant condition | Inspect for discoloration, oil contamination or suspended material. Contamination indicates a developing internal problem. |
| Coolant replacement | Per specification. Old coolant loses its corrosion protection even when it looks acceptable. |
| Radiator cap | Test at the specified interval. A cap that does not hold pressure lowers the boiling point and causes coolant loss. |
| Thermostat | Test or replace at the specified interval. A stuck-open thermostat causes overcooling and fuel inefficiency; a stuck-closed one causes overheating. |
| Hoses and clamps | Inspect for hardening, cracking and swelling. Hoses fail from the inside as well as the outside. |
| Fan drive and belts | Inspect for wear, correct tension and slipping. A slipping belt reduces airflow exactly when the engine is working hardest. |
How to confirm it
- Clean the cooling stack before testing anything
Blow or wash the cores clean from the fan side and check with a light from the other side. If you cannot see through the core, no test you run afterwards is meaningful, and a large share of overheating complaints end here.
- Check coolant level, concentration and condition
Use a refractometer for concentration rather than relying on appearance. Look for oil film, discoloration or suspended material — each indicates a different developing problem, from a failed oil cooler to a head gasket.
- Inspect the radiator cap and test it
A cap that does not hold its rated pressure allows the coolant to boil at a lower temperature and to escape. Caps are inexpensive, frequently overlooked and responsible for a meaningful share of coolant loss complaints.
- Test the thermostat
Remove and test the thermostat for correct opening temperature and full opening, or replace it as a scheduled item. On machines with a history of overheating, replacing a thermostat is a cheap way to eliminate a variable.
- Inspect hoses, clamps and the fan drive
Squeeze hoses to check for internal degradation, look for swelling or hardening, and check belt condition and tension. A hose that fails in service usually takes the coolant with it in seconds, and the engine follows shortly.
- Check for combustion gas and oil in the coolant
Bubbles with the engine running, or an oil film, point to a head gasket, liner seal or oil cooler fault. These are not cooling system problems but they are found here, and they need addressing before further overheating damage occurs.
What to do about it
Cleaning resolves most load-related overheating. Build the cleaning interval around the site conditions rather than the service sheet, and inspect visually — a light behind the core is a better test than a schedule.
Coolant concentration outside specification: correct it. Too weak provides no freeze protection and less corrosion protection; too strong reduces heat transfer and can cause other problems. Both are easy to correct.
A radiator cap that fails its test: replace it. This is one of the cheapest repairs on the machine and one of the most commonly missed causes of coolant loss.
Persistent coolant loss with no external leak, or combustion gases in the coolant: stop working the machine under load until diagnosed. Coolant in a cylinder can eventually cause hydraulic lock and a bent rod, which is a much larger repair than a gasket.
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Request a quoteFrequently asked
How often should I clean the radiator?
Inspect at every service and clean whenever you cannot see through the core. On dusty sites this is more frequent than most schedules assume. It is a low-cost task that prevents a high-cost failure.
Can I use water instead of coolant in an emergency?
As a temporary measure to get the machine to a workshop, yes. As a permanent fill, no: water provides no freeze protection and no corrosion inhibition, and it damages the system over time. Restore the correct coolant mixture as soon as possible.
Why does my machine overheat only sometimes?
Intermittent overheating usually follows load or ambient temperature, which points at cooling capacity rather than a component failure. Check the core condition first, then coolant specification and fan drive, before suspecting the thermostat or water pump.