If your water pump is not functioning correctly and you need a new one, you should replace it immediately. It can be dangerous if you continue to use broken water pumps as chemicals can leak into the pool along with the pump not doing its job.
You will need the following tools to complete your pump's replacement
- Wrench set (racheting is preferred)
- Small magnet for fishing any dropped parts out
- Metric socket wrench set
- RTV sealant
- Two bolts of medium size
Jack up the front of the machine and drain the coolant. You may choose to save this coolant if it has not received much use. You can later put that same coolant back in the pump. To create some slack in the timing chain, you will need to remove the timing chain tensioner. The timing chain tensioner is a bulging metal, usually black part in tank pumps. You should see four screws that you will then unscrew. Find the spring-loaded piston and hold that carefully as you remove the retaining bolts. If you do not carefully hold the piston, it can shoot out and get lost in another part of the pump. This is why you will need the magnet, in case this happens. You may also want to remove the power steering belt. Doing so will make the job easier, but you must remember exactly how you took it out, as there will be more work required to re-install the piece.
Once you have removed the pieces, you will want to turn the crank pulley counterclockwise so there is some chain slack. You will then find three more screws that are holding the water pump in place. Remove these bolts, being careful to not drop them into the timing chain cover. Carefully lift the pump out using a jack until you can turn and wiggle the pump out with your hands. Some coolant may come out, and you will need to replace the oil.
You will replace the O-ring seals if you will only be replacing some parts of the pump. In the case of a new pump, you can skip that step. Cover the seals with coolant liquid. Very gently replace the pump into its place, being careful to keep the new seals from touching any metal surface. Put the bolts back in and keep the timing chain over the water pump gear's teeth. Push down on the piston to successfully reinstall the timing chain tensioner. Carefully replace the covers and screw them in to place using the screws you set aside. Don't forget to replace the coolant.