Mechanic's tips - How does the excavator cooling system work?
What is coolant?
The main fluid that maintains engine temperature is coolant. It is usually sold ready to use, but sometimes there are concentrates that need to be diluted 1:1 with distilled water. Do not use the concentrate alone – only when mixed with water does it gain the property of not freezing even down to -30°C. Also, do not use water alone, as it causes limescale and sediment buildup that clogs radiator channels and damages engine block components.
Small and large cooling circuit
- Small outline – the fluid circulates only through the engine and the operator's cab heater.
- The Great Outline – is supplemented with a radiator and a thermostat, allowing the fluid to flow more widely.
Thermostat function and signs of malfunction
The thermostat is responsible for smooth switching between the small and large circuit. It opens when the fluid temperature exceeds ~93°C, allowing the fluid to enter the radiator, where it cools down by about 20°C. After the temperature returns to normal, the thermostat closes again.
In the event of a thermostat failure, it may remain open (the engine does not warm up - higher fuel consumption, pollution) or closed (the engine overheats - risk of damaging the gasket or even jamming completely). It is recommended to replace the thermostat every 3 years or every 3000 engine hours. – together with the coolant change.
Our offers thermostats.
Water pump in the cooling system
Water pump ensures that coolant is constantly circulating from the engine block to the radiator and back. It is driven by the engine - either by a timing gear or a belt. One of the most common causes of failure is an improperly tensioned or worn belt, which causes bearing failure and fluid leaks. The water pump must be replaced together with the timing belt.
Our offers water pumps
Coolant expansion tank
When the temperature of a liquid increases, its volume increases. To avoid air bubbles, which may disrupt the flow of fluid, is used expansion tank. When the temperature is too high, excess liquid is removed through pressure cap, and the tank pressure is usually ~1 atmosphere. The tank is usually marked yellow cap.
IMPORTANT!
Never open the tank when the engine is hot or running! First, turn off the engine and wait until it cools down. Only then carefully unscrew the cap and add fluid. Otherwise, you may be scalded by boiling fluid.
