Water pump, cooling system
Automotive illustrated glossary
 Engine cooling system |
 Water pump |
A water pump pushes the coolant through the passages (water jackets) in the engine cylinder block and cylinder head and then out into the radiator. This helps to keep the engine from overheating; the hot coolant passes through the radiator where it cools down and then returns back to the engine.
A water pump is usually driven by the engine through the drive belt. Sometimes it's driven by a timing belt. A water pump consists of the housing with the shaft rotating on the bearing pressed inside.
At the outer side there is a pulley mounted on the shaft. At the inner side there is a seal to keep the coolant from leaking out and the impeller that acts like a centrifugal pump (see the lower picture).
Water pump problems
Typical water pump problems include coolant leaks, noisy or defective bearing, damaged or corroded impeller.
Faulty water pump might cause the engine to overheat, which can result in serious engine damage. If defective, a water pump is replaced as a unit.
Is it worth to replace a water pump when a timing belt is being replaced?
Sometimes you might be suggested to replace the water pump at the same time the timing belt is being replaced. In cases when a water pump is driven by a timing belt it's worth to do because it involves very little extra labor, plus, a water pump is subject to wear anyway. As long as the original parts are being used, I'd recommend to go for it.
If you're looking for information how to replace a water pump or other repair information for your car, there are couple of websites where for a fee you can get an access to an online repair manual for your car or truck. Follow these links:
• Alldata DIY - online automotive diagnostic and repair information
• eAutoRepair - professional service and repair information to automotive enthusiasts.
