Water pumps are what keep gasoline combustion engines from overheating as you drive your car or truck down the highway. The water pump circulates water through the engine to keep the internal components from overheating and seizing. Because of the water pump’s often hard-to-reach location on the engine, it may seem difficult to determine whether the water pump is bad or not. However, it is actually relatively easy to test a water pump for failure and even the most inexperienced mechanic can perform this troubleshooting test.
.Open the car hood and locate the thermostat on the top of the radiator lid. Pull the thermostat and start the car. Watch the temperature gauge carefully. If the water pump is working properly, the engine should take a long time to warm up (if it ever does). With the thermostat removed, the coolant should circulate continuously, making it harder for the engine to warm up.
Turn the car off and locate the water pump and the water pump drive belt in the engine compartment. Use the wrench set to loosen the belt retaining bolt and pull the belt off of the pump. Spin the belt drive with your hands to see if it rolls smoothly and to determine if there is any movement or “play” in the driveshaft. If the pump seems in good working order, replace the belt, tighten the retaining screw back up.