To read an engine coolant system diagram, start from the radiator. Air flows through the radiator and the cooling fan to cool the water that circulates through the engine. The water reaches the heater core and hoses, raising the temperature on the thermostat, located on the top of the system. The hot water returns to the radiator through the heater hoses, where it is again cooled and recycled back through the engine.
Understanding the function of each part of an engine coolant system is crucial. The system begins at the radiator, which both holds the cool water and receives the heated water after it has travelled through the engine so that it can cool once more. The water is brought to and from the radiator using the rubber radiator hoses located on the top and bottom of the radiator. These hoses must be well-maintained to prevent cracking and should be replaced as soon as any damage becomes apparent.
The water pump provides the force for the water to move throughout the coolant system. It is powered by a belt.
The thermostat and its housing monitor the temperature of the engine. It alerts the driver if the coolant begins to fail and the engine overheats by activating the thermo-time switch. Cooling fans help to maintain a comfortable temperature, as they bring in outside air to keep the water cool.