A vehicles water pump is a vital component of the cooling system of an internal combustion engine. The water pump works in connection with the engines thermostat to regulate the internal temperature at operational levels by removing heat from the engine.
The water pump is a centrifugal pump driven by the serpentine belt connected to the crankshaft. The pump helps to circulate coolant from the radiator through the engine removing heat from the engine and allowing the coolant to reduce its temperature by returning to the radiator.
The main bearing is a typical failed part of the water pump which causes the coolant to leak. Antifreeze has a special lubricant in it which helps to lubricate the water pump bearing, however if water is used this will shorten the life of the bearing. Water can create sediment and increase the wear of the moving parts within the water pump. Another common failure is the hardening or shrinkage of the seal. Both the bearing and seal can fail over time by normal and excessive wear and tear.
Typically the water pump warranty is covered under the powertrain warranty section of a car's warranty. Essential to the health of the engine is to have a fully-functioning water pump to avoid overheating and engine wear and tear on the engines components. Although, some extended auto warranties cover breakdown due to wear and tear, most do not. Make sure your vehicle's water pump is covered under warranty by choosing an extended warranty with "wear and tear" and "seals and gaskets" coverage.