Water pumps

The water pump continuously circulates engine coolant through the cooling system—from the radiator to the engine and then back again. If the water pump fails the vehicle will run hot and possibly suffer serious damage from engine overheating.

The water pump takes its power from the engine. Some operate through a belt and pulley and others via a gear or chain. This power is transferred to a shaft on which there is an impeller. The impeller spins and circulates coolant in much the same way a propeller works on a boat or airplane to move water or air. The shaft and impeller spin on a sealed bearing, and this bearing is the part of a water pump that usually wears out.