Your car is equipped with a cooling system to keep the engine from overheating on the road, and it works by pumping a mixture of antifreeze and water through the car to remove excess heat and regulate internal temperatures. The water pump is responsible for keeping the coolant flowing, and when it breaks down the engine will overheat, which can cause unnecessary damage.
Eventually the water pump will wear out and need to be replaced. This typically happens when the car gets close to the first 100,000 miles, but it can vary from vehicle to vehicle. The owner's manual may contain more specific information, and you can also keep an eye on the pump and watch for signs it may be failing.
Leaks tend to be the most common problem when a water pump begins to break down. There are rubber seals that can break down and the gasket may warp if the coolant runs dry or the engine gets too hot. Most importantly, you should watch the coolant levels and address any leaks that may crop up in the hoses or anywhere along the cooling system. You can also examine the water pump for signs of damage around the seals or hose connections. If you notice the coolant levels are low shortly after adding fluids, there could be a leak.
To determine if the water pump is leaking, you can park the vehicle on a dry, level spot overnight and place a large sheet of white paper under the approximate area where the pump is located. The owner's manual will indicate the placement of the water pump for those who are unsure. In the morning, check the paper for traces of coolant. This liquid is generally a bright green, but it can come in other colors, or it may appear to have a rusty orange hue if it is dirty. In this case, you may want to change the coolant once the leak has been addressed.
You can also visually inspect the water pump for signs of a leak or other issues, but be sure the engine has been off for a reasonable amount of time so the parts will be cool to the touch. The pulley that transfers power from the engine belt is the first thing to check. Give it a wiggle - it should not move, but if it does, this could mean that the bearings are worn and you will need to replace the pump. To double-check the state of the bearings, leave the hood open and start the car. Listen closely for grinding noises coming from the water pump. This is the sound of bad bearings.
If you decide to go the DIY route and replace the water pump yourself, the first step is to make sure the engine is cooled down before beginning. Then, you will have to disconnect the ground wire of the battery and drain all of the coolant from the cooling system. Once this is done, you may need to disconnect and remove the car's drive belts and other accessories to gain access to the water pump.
From here, you can begin disconnecting the hoses attached to the pump. Then loosen the screws holding it in place and gently remove it from the engine bay. Inspect the gaskets to ensure they are not warped or cracked and replace these if necessary. Following the owner's manual specifications for the appropriate torque, put the new pump in place and securely screw the bolts on to the proper pressure specification.
Reconnect the hoses and then put everything else back into place, taking care to check the tension on any belts that were removed for the procedure. Refill the coolant, reconnect the battery and start the car to get the coolant flowing through the system and ensure everything is operating smoothly.