Cooling system

cooling system, apparatus employed to keep the temperature of a structure or device from exceeding limits imposed by needs of safety and efficiency. If overheated, the oil in a mechanical transmission loses its lubricating capacity, while the fluid in a hydraulic coupling or converter leaks under the pressure created.
The cooling system serves three important functions. First, it removes excess heat from the engine; second, it maintains the engine operating temperature where it works most efficiently; and finally, it brings the engine up to the right operating temperature as quickly as possible.