How to Remove a Water Pump Pulley

Water pumps quickly burn up if coolant levels are too low. Unfortunately, coolant leaks are fairly common in older vehicles and water pump failure is the result. Once the pump wears out, engine failure is imminent. A new pump is the solution, but replacing it can be frustrating, unless preparation is taken. One of the most difficult steps in the removal of the pump is simply accessing the bolts securing it in place, which are often hidden by the water pump's pulley, which is itself difficult to remove. Fortunately, mechanics have already devised a method of doing this.

Things You'll Need:

• Pulley removing tool (adjustable)
• Socket set / wrenches
• Screwdriver set

1. Remove obstacles away from the water pump

Remove obstacles away from the water pump. Often alternator and air conditioner compressor belts will be in the way. Depress the belt tensioner associated with the belt to be removed, which maintains constant tension of the belt, to obtain enough slack to slip the belt off. The tensioner is a spring which pushes against a belt and manually pushing it the opposite way will release the tension.

2. Remove the engine's timing belt or chain if necessary

Remove the engine's timing belt or chain if necessary, as this is often in the way of the water pump. Record the orientation of all associated sprockets with respect to each other, as it will be necessary to reinstall the timing chain in the exact same way for the engine to run properly. A notch is usually engraved on one tooth of each sprocket; ensure that each notch is pointing in the same direction when the timing chain is replaced.

3. Remove the water pump belt from the water pump

Remove the water pump belt from the water pump. Depending on the specific mechanics of the vehicle, determined by the manufacturer, this belt may drive solely the water pump, or a serpentine belt which wraps around the pulleys of many other devices, such as the power steering pump and alternator. The belt need not be taken off all of the pulleys unless doing so is necessary to access the water pump.

4. Install the pulley removal tool to the water pump pulley

Install the pulley removal tool to the water pump pulley. The tool has two clips which are placed behind the pulley and a screw which pushes against the pump rotor. The tool will apply pressure to the shaft to push the pulley off the pump. It is difficult to obtain a secure fulcrum to pry the pulley off using a screwdriver or prying bar, and doing so will necessarily put pressure on other parts of the vehicle's mechanics, such as the engine, other pumps, and exhaust manifolds, and may cause damage to them. Additionally, the angular force on the water pump itself could bend the bolts bonding it to the engine and can make the removal harder.

5. Tighten the removal tool slowly

Tighten the removal tool slowly. Some removal tools require a ratchet drive socket to turn the screw, while others can be turned by hand. As the removal tool's screw is rotated, it extends toward the shaft of the pump rotor, while its side clips undergo an opposite force pulling the pulley from the rotor. The even pressure applied by the removal tool will force the pulley off the water pump rotor without cracking or bending the pulley.

Tips and Warnings

Take photographs during disassembly to help remember where parts go and which screws go where to ease the process of putting everything back together. Depending on the specific vehicle, the water pump may be easily accessible or it may require removing dozens of components to be able to get a wrench to it.

The engine must be off while performing this procedure. The engine and all connected parts may be extremely hot and coolant pressure may cause severe burns. Allow adequate time for the engine to cool before beginning this procedure.

Wear safety glasses to prevent any dirt or projectiles from damaging your eyes. Nylon gloves can protect your hands from gasoline and oil, which contain carcinogens.

Video: Removing Water Pump Pulley Without Using Impact Wrench

Comments on this video:

• So I’m about 8 hours into a head job on my evo, long story short most of the components on the timing cover are off and I was in the process of taking the timing cover off when I realized the water pump pulley is covering one of the bolts… only way I personally knew how to take them off was to crack them loose while the belt was still on so anyways, you just saved me hours of putting things back together. Thank you :)
• Good tips. However, after rounding off all three pulley bolt heads, I left the pulley on and removed the six, 10mm bolts holding the water pump on instead, using a 10mm box end wrench—surprisingly doable. Once removed, and off the vehicle, a bit of leverage from a box end wrench, plus a six point, 10mm socket broke the three, rounded bolts loose. I replaced the rounded bolts with fresh bolts from the hardware store.