Figure illustrated above describes the functioning of cooling system of an automobile. The key components used in a cooling system are pressure cap, heater hoses, thermostat, heater core, reserve tank, lower hose, transmission cooler, water pump, fan, radiator and upper house. The cooling system of a vehicle operates or functions by directing liquid coolant via passages in the engine block and heads. After that the liquid coolant which flows through passages absorb the heat from an engine. Then this fluid passes through a rubber hose to reach to the radiator. At this stage the hot liquid is cooled by air stream entering the engine compartment via grills. Once it gets cooled, then it goes back to engine and same process repeats again.

One of the most important parts of the cooling system is also the most invisible

The head gasket must maintain the seal around the combustion chamber at peak operating temperature and pressure. The gasket must seal against air, coolants, combustion and engine oil at their respective peak operating temperature and pressure. The materials used and design employed must be thermally and chemically resistant to the products of combustion and the various chemicals, coolants and oils used in the engine.