The water pump pushes coolant from the radiator through the coolant system, into the engine and back around to the radiator. The heat that the coolant picked up from the engine is transferred to the air at the radiator. Without the water pump, the coolant just sits in the system.Water pumps are used for pumping and draining water, cleaning water features and pools or to stop structural foundations from becoming submerged.Responsible for pumping water. When the engine is started, the Water Pump will operate through the belt, pumping the bottom coolant coolant around the engine, and pumping out the engine hot coolant into the cold coolant. Generally, when the car is cold, the cooler does not pass through the water tank and only circulates inside the engine. However, when the engine temperature reaches a certain temperature, it will be turned on to allow the cooler to absorb heat from around the engine, and then send it to the water tank to use the fan and the “wind hitting” during driving. "Do a cooling effect.