How to Remove a Water Pump Pulleyby Jesse Randall
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.
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.
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.
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.
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.
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.
Things You'll Need
- Pulley removing tool (adjustable)
- Socket set / wrenches
- Screwdriver set
Jesse Randall studied mathematics and physics and works as an embedded electronics engineer, developing microcontroller firmware and digital interfaces. He writes about subjects including abiogenesis, electrochemistry and algorithm optimization. He has been writing on technology-related subjects since 2000.