There's a lot of metal under your vehicle's s hood, most of it surrounding your engine's internal components. And that metal generates a great deal of heat during driving. So a properly functioning cooling system, which circulates antifreeze/coolant, is absolutely necessary to keep heat from building up to destructive levels. Your car or truck has 5 principal components to its cooling system. Radiator. An auto radiator has a set of tubes called the "core" that the coolant flows through. By passing through the core, the coolant is reduced to an acceptable temperature before going into the engine once again. Radiator cap. There has to be a place to pour in coolant and the radiator cap covers that filling hole, while also increasing the boiling point of the coolant to make it more efficient. Radiator hoses. The coolant goes from the radiator to the engine through a series of hoses that must be sturdy and flexible enough to handle engine vibration and high heat. Thermostat. Like the device on your home heating/cooling system, the engine thermostat keeps the engine at the right operating temperature. Water pump. This mechanism drives coolant through the whole cooling system, in addition to the engine block. To keep all these components at peak efficiency, Midas recommends having a "flush and fill" performed on a regular basis. Old coolant, which over time breaks down and gathers impurities, is drained, the cooling system is flushed with water, and then refilled.