Pool Care Pool Equipment

15 Steps to Replace Your Pool Pump Motor (Yourself)

15 Steps to Replace Your Pool Pump Motor

A pool pump is a crucial piece of pool equipment that has to stay operational to better your swimming pool. When its motor dies, it’s up to you to replace it with a new one to make sure the pool pump runs as required. So, how do you replace a pool pump motor?

You have to get a perfect replacement for your pool pump model along with the gaskets, seal, O-rings and the disassemble tools. With all these items at your disposal, shut off the pump breaker, remove the wiring and disassemble the pump motor, impeller, and diffuser. Get the new pump motor, set it up and then reassemble it to the pump housing.

Replacing a pool pump motor isn’t that complicated. And the best part is, the procedure works the same with other pool pump motors. However, you have to follow the replacement steps for a successful change. So, continue reading to know how to do it right.

Best Way to Replace a Pool Pump Motor

The steps to replacing a pool pump motor are straightforward. All you need is the right tools and materials. But, you still need to do it right by following the correct replacement process. You don’t have to sweat doing it, but you need to take it systematically, step by step. So, where do you start?

Step 1: Get Your Materials

The first thing you need to get is the pump motor. You need to look for a few things, such as the horsepower (hp) matching your oil motor. It has to match your pump’s impeller hp for it to be compatible.

You will also need to replace the pump’s mechanical shaft seal, which you can buy separately, or get a pump motor replacement kit that comes with the seal, gaskets, and O-rings for your swimming pool pump. You will have to make sure it’s made for your pool pump type and model.

You’ll have to replace the gaskets and O-rings if they are out of shape. If they are okay, you’ll need some magic lubricant to keep them in shape till their time comes.

You will also need some tools for disassembling the pump motor and reassemble the new pump motor, like a wrench and a screwdriver for the wiring.

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Step 2: Shut Off the Power to the Pump

With your materials ready, it’s time to get them set up ready for the next step. What you need is to shut off your pump’s breaker. You want to make sure there is no power flowing through the wires before working on it.

Step 3: Disconnect the Wiring

Unscrew the six or so screws that hold the seal cover to expose the wiring. You should see a set of three wires; eight red-black-green for 240 volts system or black/red-white-green for 110 volts.

The green wire connects to the green screw head. If your pump motor is a 2-speed model, there will be four wires – for such a model, it’d be best to label them.

Start by unscrewing the ground wire, mostly the closest to the top. The wiring is straightforward. What you want to do is carefully pull the wires after unscrewing them.

Step 4: Close the Valves

With the wiring out, you want to shut off all the incoming pool valves getting water to the pump and out of the pump, especially if your pool pump is below the water level.

Step 5: Unscrew the Old Motor

Remove the clamp assembly or unscrew the seal plate that holds to the pump housing. Usually, you will find a clamp band connecting the seal plate to the impeller housing or volute. At times, the seal plate will be held by 4-6 bolts. With the bolts out, pull out the motor and the pump rear from the housing.

When pulling the pump motor out, it will come out with the seal plate. You might need to pry it with a flat head screwdriver gently to make the separation of the two have easy. Place it on a clean working surface – it could be a workbench, a table, or a wood sheet.

Step 6: Remove the Diffuser

After the motor is out of the way, reach the impeller shroud and pull it off. You might need to remove some screws in some models. Remove the diffuser and set it aside. Keep tabs on the shroud gasket.

Step 7: Remove the Impeller

You want to secure the motor shaft, so it spins off the impeller. The impeller has regular threading, and you spin counter-clockwise when removing it.

If your pump is an older model that has an open bracket allowing you to see the shaft, hold it with channel locks of vice grips at this point and tight when spinning the impeller.

The modern pool pumps don’t have access to the shaft. In most cases, the best and convenient way to the shaft is by opening the motor back cover. You might need to loosen the capacitor to move it out of the way and insert half-inch wrench on the shaft end from the back. Usually, the shaft will be slotted to accept the 1/2” wrench.

Removing Pool-Pump-Impeller

There will be a centrifugal switch on the motor shaft end. You want to insert the wrench behind it on the shaft end and prop the handle up against your motor’s body to hold the shaft tight and snag. At the same time, grab the impeller tightly and turn it counter-clockwise.

If it proves to be challenging to remove it by hand, get large channel locks and use them to remove them gently. Don’t use too much pressure, as you will be risking breaking the impeller.

You might come across a pump model with a reverse threaded impeller screw. For such, you want to look at the impeller center after pulling the motor out. If there is a screw head, you want to get a fitting screwdriver to remove it. Remember you’re turning it clockwise since it is reverse threaded.

Mostly, the screw will be brass. At times it can soften out – so avoid damaging it; use a fitting screwdriver.

Step 8: Remove the Seal Plate

You have to remove the four bolts holding the seal plate to the motor. Once the bolts are out, you might want to pry the plate to remove it. Remove the seal half in the center plate.

Step 9: Install the Seal Plate

Take the new motor, bolt the seal plate from the old motor, and firmly press the shaft seal half into the seal plate as it was in the old pump motor.

What you want is to avoid touching the ceramic face with dirty or greasy hands. Also, avoid the seal half getting scratched.

If it’s too tight, get a small piece of one-inch pipe and a light cardboard shim to fit the seal down the shaft. You can use a rubber lubricant but keep it far from the ceramic.

Step 10. Install the Impeller

Unlike the difficult time installing the seal plate, installing the impeller is much easier; all you need is to thread it on. However, you’ll have to install the half-seal that has a spring first. What you want to make sure is, take slowly and ensure it goes correctly.

Best Way to Replace a Pool Pump Motor

On one side, it has a soft rubber and a hard plastic on the other side. The plastic end faces the ceramic side of the half seal, while the rubber end faces the front towards the impeller.

If your motor impeller has a screw, you will want to replace it once you spin it onto its position of the shaft. If by any chance, your pump motor is a ‘keyed shaft’ type, you’ll have a brass stub shaft to fit over the keyed shaft.

Once you’ve threaded the impeller onto the stub, align the impeller close to the seal plate and tighten the screws holding the stub shaft to the keyed shaft.

Step 11: Replace the Diffuser

Before reinserting the pump motor to the housing, ensure you replace the diffuser over the pump impeller. Many people forget about this step. Ensure the diffuser O-ring or gasket seats are well in place before you slide in the motor. Apply some lubricant to the gasket or O-ring to condition it.

Step 12: Install the New Motor

Slide the motor into the housing and clamp it to ensure its seal place it making enough contact all way round. Lubricate the seal place O-ring to give it a good fit and help hold it to the groove while positioning the two parts.

Tighten the bolts working then out diagonally. Make sure they are tight and snug but don’t use too much force. Do the same if your pump uses a clamp band. Tap a clamp band around the edges tight to give it a good fit.

Step 13: Replace the Wiring

Usually, a 240-volt pump motor will come wired for a 240-volt system to prevent damage when hooked up to a 115-volt system.

However, the wiring should be easy. Run the wires through the conduit. Nest, assuming you noted the orientation of the wires while disassembling the motor, the green wire goes to the bolt with a green mark. The other two, red or black and white, brown and blue, or red and black, go to lines one and two.

Some pump motors will comes with a label to guide you, especially if your model has a reversible 115/240-volt system. If not, look for a simple round switch under the last voltage line, which, when you rotate it, select either of the two voltages.


  • Make sure the wires are not touching
  • Inspect the wires for deteriorated casings or bare spots
  • Tighten the wire connection firmly

Step 14: Replace the End Cap

With the wiring all done, replace the end cap. Make sure you don’t pinch the wires as that would cause a short circuit or worse.

Step 15: Test Run the Motor

If everything is step up, open the valves, fill the pump basket with clean water and engage the pump breaker. It should be up and running in no time.

And that’s it; you have replaced the pool pump motor successfully!

Related Questions

How much does it cost to replace pool pump motor by yourself?

Depending on the model and power (horsepower), a new replacement pump motor will cost you around $150 – $1000, depending on the model and power (horsepower). A set of the replacement necessities might cost you $15 – $100 extra.

About the author

Sharif Miah

Hi! I'm Sharif, the founder of Globo Pool® and I have been working in the pool & hot tub industry for the last few years. I love to share my experiences with people & hope you are enjoying my information and lessons!

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