How To Replace Your Pool Pump Shaft Seal

Written by Michael Dean
January 20, 2024

pool pump shaft seals

Pool pumps are an essential piece of equipment for keeping your pool water clean. And an important part of your pool pump system is the pool pump shaft seal, which helps seal up the main motor, preventing it from getting wet and damaged. If your pool pump shaft seal wears out, you’ll need to replace it to ensure your pump is functioning properly.

In this guide, I’ll walk you through my step-by-step process of replacing your pool pump shaft. I’ll also address when you might need to replace your pool pump shaft seal and how to find the right one for your swimming pool.

Main Takeaways

  • Replacing your pool pump shaft isn’t rocket science, but it is a slightly complex process that you should consider hiring a professional for.
  • It is important to refill your pump with water before turning it on after installing a new pool pump shaft seal.
  • You can usually find your pool pump shaft label on the exterior pump to ensure you get the right model number.
  • You’ll need to replace your pool pump shaft every time you replace your pool pump motor.

Step-by-Step Process: How to Replace Your Pool Pump Shaft Seal

A pool pump shaft seal is a small circular piece of metal and rubber that adheres to the pool pump’s impeller and motor shaft. This small part is essential to keep water from entering the pool pump motor. Without the right-sized pool pump shaft seal, your new pool pump motor will likely flood and malfunction.

Supplies Checklist

  • Pliers or a spanner (if pump shaft contains bolts)
  • 1/2″ wrench
  • Work gloves
  • Screwdriver
  • Gasket silicone (Blue RTV)
  • New pool pump shaft seal

Step One: Purchase a New Pool Pump Shaft Seal

You’ll need to purchase the replacement part before you begin replacing your pool pump shaft seal. I go into depth below on how to ensure you buy the right replacement.

Step Two: Turn off Your Pool Pump

First, make sure your pump is off before you start working on it. I recommend completely shutting it off and disabling any timers to ensure it won’t turn back on during the process.

Step Three: Release the Pool Pump Motor

Next, it is time to start dissecting your pool pump. If your pump has bolts holding the motor to the pump basket, grab a spanner or a pair of pliers and remove the bolts. Some pumps will simply have a clamp band holding them together, so you’ll just need to loosen the band.

Step Four: Remove the Pump Motor From the Housing

Once you have removed the bolts or released the clamp band, grab the pump motor and remove it from the main housing. If you have been recently running your pool pump, I recommend waiting an hour or so for it to cool down, as the pump can get quite hot.

Step Five: Remove the Impeller Cover

Next, remove the cover of the impeller and any covers that are blocking your access to the motor.

Step Six: Remove the Pump Impeller

Next, it is time to remove the impeller from the pool pump shaft. You’ll first need to loosen and move the capacitor and then hold the pump shaft in place while you unscrew the impeller.

Step Seven: Disconnect the Old Pump Shaft Seal

Use a screwdriver to remove both sides of the shaft seal from the pump shaft and impeller. You may be able to remove it without a screwdriver, but a flathead screwdriver makes the job a lot easier.

Step Eight: Clean the Equipment

Inspect the seal plate, pump motor, impeller, and other components. If they are dirty or corroded, clean them thoroughly. If you aren’t sure how to clean a pool pump, head over to my article on the topic.

Step Nine: Install the New Shaft Seal

Now, it is time to install the new shaft seal. Place the smaller “donut” half of the pump shaft seal on the seal plate with a bit of gasket silicone smeared on it to secure it in place. Then, place the other half of the seal on the impeller with the softer end against the impeller and the plastic end facing toward the motor. It is important to place the shaft seal correctly; otherwise, your pump will leak.

Step 10: Reassemble the Pool Pump

After replacing the shaft seal, it is time to put your pump back together again. Reinstall the seal plate and screw on the impeller. Ensure that everything is sealed up and tight, then place the motor back into the main pump casing. Finally, you should retighten the clamps or reinstall the bolts holding the pump in place.

Step 11: Refill the Pump with Water and Turn It On

Congratulations! You have successfully replaced your pool pump shaft seal. Now, it is time to get your pump running and ensure all your hard work was not in vain. Prime your pump by releasing the air inside and refilling it with water. Then, turn the pump on and make sure it is not leaking.

When to Replace Your Pool Pump Shaft Seal

Pool pump shaft seals are not something you need to replace often. However, while pool pump shaft seals are made to withstand high speeds and moisture, they’re not infallible. These components can begin to tear, flake, and deteriorate after prolonged exposure to chlorinated water or fast-moving motor shafts. When this happens, the seal no longer keeps water from getting inside the motor, causing the motor to take on moisture and eventually break down.

You should also replace your pool pump shaft seal if you replace your pool pump motor. A worn pool pump shaft seal can leak water into your pump’s motor, leading to motor failure. So, replacing your pool pump shaft seal at the first sign of damage might also be a good idea.

How to Prevent Your Pool Pump Shaft from Wearing Out

Maintaining your pool pump components, including the shaft seal, could be the best way to extend your pool pump motor life.

Use the Right Seal: Choosing the proper seal for your pool pump is imperative. If your pool pump shaft seal is the wrong size, it may flood your pool pump, causing irreparable damage.

Make Sure Your O-rings Are Lubricated: You won’t need to lubricate your pool pump shaft seal specifically, but the O-rings should be lubricated. If not lubricated, they can dry out, causing water to seep and damage your pool pump shaft seal.

Periodically Check and Clean Your Seal: If you suspect your pool pump is leaking, check your shaft seal for damage. It may just need to be cleaned off, in which case you can wipe it off and remove any corrosion.

How to Find the Right Pool Pump Shaft Seal

When replacing your pool pump shaft, finding the proper replacement shaft seal is important. Choosing a shaft seal that’s the wrong size or shape can be disastrous. Generally, you’ll only need to do two simple things to find the proper pump seal:

  1. Locate your pool pump’s label
  2. Order a replacement pump shaft seal

Fortunately, most pool and pool pump manufacturers use specific components for each make and model. This practice helps eliminate accidental pairings and motor failures. However, to pick up the right-sized shaft seal, you’ll need to have your pool pump’s make and model information on hand.

Can’t Find the Model Number?

You might know the make of your pool pump, but sometimes, finding the model number proves to be much more difficult than expected. The pool pump’s make is often painted along the outside of the pump, but the model number might be embossed or printed in far smaller text along the pump’s rims, body, or internal components.

In most cases, you can find your pool pump’s label on the exterior of the pump housing. This label often features the brand name or maker’s name, electrical information, and helpful specs. It should also list the make and model of the precise pool pump.

For example, you could find a shaft seal that fits a wide range of popular pool pump motors, but struggle to find one that neatly attaches to your pump’s impeller. That’s why it’s crucial to find the pool pump model number.

How to Find a Pool Pump Shaft Seal Without a Label

If you can’t find a label on your pool pump, you can still find a  replacement shaft seal that works. You’ll simply need to examine your pool pump’s various components and look for a series of identification numbers.

Most pool pump parts are stamped with helpful model identification numbers. You might be able to find this number multiple times while looking at the following:

  • Plastic pump housing
  • Pump strainer lid
  • Pump strainer basket
  • Impeller
  • Diffuser

Need Some Maintenance Help?

Send me a message! I can answer any of your pool maintenance, equipment, or other questions.

Replacing Your Pool Pump Shaft Seal: DIY vs. Professional

It is possible to replace your pump shaft seal DIY, but hiring a pool pro can ensure the job is done correctly.

If you’re planning on replacing your worn-out pool pump motor and shaft seal without professional assistance, you’ll likely end up disassembling the impeller and diffuser from the body of the motor. This dissection of your pool pump is pretty complex, so if you aren’t very confident in your technical skills, I highly recommend employing a professional.

On the other hand, if you hire a professional pool technician, your life will be much easier as they will assist you with every step, from finding the model identification number to ordering the correct replacement seal and installing the new components.

Keep Your Pool Pump Sealed

Replacing your pool pump shaft seal is important any time you replace the motor or if the seal is simply worn out. This piece of equipment may just be a small piece in the puzzle that makes up your pool circulation system, but if the seal breaks, your pump motor can be flooded with water, which can be disastrous!

If you’re having other issues with your pool pump, I have a complete guide on what to do if your pool pump is not working and check out my top pool pumps if you need to replace the entire unit.

Questions about finding the right seal replacement? Shoot me a message; I’m always happy to help.

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