4 Types of Water Pumps

Water Pump Failure

Manufacturers commonly recommend replacing the water pump after about 60,000 miles. There are several signs of water pump failure.

• Sudden overheating of your coolant. You might notice a change in the coolant temperature gauge reading. Or the radiator could overheat, with the coolant boiling from the radiator cap.
• Seeping coolant. Pumps have a weep hole designed to let water escape (or weep out) if it leaks past the bearing or seals. The coolant loss is noticeable, with a crusty residue around the weep hole and coolant trickling to the ground.
• Whining noise. Bearings emit a noticeable whine when they are worn out. The sound increases in pitch/volume as engine rpm rises. Open the hood and verify if the sound originates from the water pump area.

Types of Water Pump Drives

You will likely encounter one of four styles of water pump drive systems.

Fan-belt drive: Older cars often use water pumps driven by a pulley connected by a belt to the engine’s crankshaft. The belt might also rotate around the radiator fan. Hence, it’s called a fan belt. In addition, other belts might be visible to provide power for the alternator and air conditioning compressor.

Serpentine-belt drive: In the 1990s, manufacturers wanting to reduce the drag on the engine devised a serpentine-belt drive design. In this layout, a long belt under constant tension connects numerous drives and pulleys in a winding path to move multiple subsystems.

Timing-belt drive: Later, many manufacturers opted to use a timing belt to drive the water pump. Timing belts are often replaced at set mileage intervals to avoid catastrophic failure. When replacing the timing belt, it is recommended to replace the water pump at the same time.

Electric drive: Many newer vehicles, including hybrids, use electric-powered water pumps. This reduces the engine’s power demands and allows the pump to cycle on and off as needed.

Considering a Water Pump Replacement

It’s essential to read your service manual to confirm the style and location of the water pump drive used by your vehicle. Most water pumps are mounted on the front of the engine block.

In today’s crowded engine bays, many parts must be disconnected and removed to access the water pump. Some designs call for replacing the pump from the bottom of the car. If a timing belt is involved, you should ensure the belt maintains the correct tension during the replacement process.

For the standard serpentine belt system, you often need to release the belt tension and remove some components before accessing the water pump. Take note of the belt’s path before removing it and, if possible, snap a picture as a reference.

For a timing-chain-driven water pump, you must remove the timing cover to access the timing belt.

Replacing the Water Pump

After you gain easy access to the water pump, follow these general guidelines:

Drain coolant. Drain the radiator coolant by opening the petcock at the bottom. Keep the drain pan below the water pump, as there may be coolant in the pump. Once all the coolant is removed, pour it into a sturdy container and take it to your local household hazardous material recycling center for proper disposal. (Most coolant is poisonous to pets. Also, remove residue that might have spilled on the ground).

Remove the pump. The water pump is held against the engine by bolts. Remove the bolts, check if some might be different lengths, and record the precise location of each bolt. After the bolts are removed, the water pump can be removed. You might need to tap it with a rubber mallet or use a pry bar to loosen it.

Clean surfaces. After the pump is gone, use a plastic scraper to remove gasket or sealant residue. You want a clean, smooth surface when mounting the new water pump. Spray the engine mounting surface with brake cleaner to remove any remaining material.

Mount the new pump. Most water pumps use a gasket or rubber seal (similar to an O-ring) between the pump and the engine surface. Follow the manufacturer’s directions and the proper method to connect this item. Mount the new water pump with the bolts. Torque the bolts with a torque wrench based on the manufacturer’s specifications. Reattach the belt and other components that were removed to gain access.

Restore coolant. Refill the radiator with coolant, following the manufacturer’s directions to remove (or burp) air from the system. Check for leaks. Take the vehicle for a short test drive to verify that the coolant remains at a proper operating temperature.

If you can access the water pump easily, this replacement job should take less than two hours. If a timing belt is involved—or if you have to remove several components to gain access to the water pump—expect a half-day to complete the job.