How To Replace a Pool Motor Shaft Seal


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If you see water leaking out of the bottom of the pool pump assembly, it's a good indication that you may have to replace the shaft seal within the motor pump assembly. As shown in the pool pump cut away, the shaft seal is located in the motor pump assembly behind the impeller. Although this description is specific to a Hayward pool pump, many of the steps can apply to other models of pool pumps.

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Things You'll Need


Step by Step


Step 1

The first step is to turn off all power to the pool pump. For maximum safety turn off the power at the circuit breaker to the motor.

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Step 2

Next you will want to remove the motor pump assembly from the wet end housing. Remove the four 9/16" bolts that bind the motor pump assembly to the housing. Note: some Hayward pool pump models have six bolts.

Step 3

Now pull the assembly apart from the pool pump housing.

Step 4

After the assembly is out, you should see the pool pump diffuser and diffuser gasket on the end of the assembly. If you do not see the diffuser or its gasket, check inside the housing.

Step 5

If the pool pump diffuser came out with the assembly, pull the diffuser off the assembly. You may have to pry it off gently with a screwdriver. Now you will see the pool pump impeller. The shaft seal is behind the impeller so you will now have to remove the impeller.

Step 6

To remove the pool pump impeller you will twist the impeller off in a counter clockwise motion. The impeller cannot be freed from the motor shaft without first securing the motor shaft.

Step 7

Move to the other end of the motor shaft in the back of the motor assembly. Take off the two screws that hold the back cover onto the pool pump assembly.

Step 8

You will see the pool pump motor wiring and capacitor. You will have to remove the capacitor to gain access to the end of the motor shaft. Capacitors store power. To avoid a possible shock, lay a screwdriver across the two leads to short out the capacitor. These capacitors sometimes burst when shorted out, so it is a good practice to place a cloth over the capacitor and to wear eye protection.

Step 9

Now unscrew the single screw that hold the capacitor in place and push it out of the way. No need to disconnect capacitor from leads.

Step 10

Place a 7/16" wrench on the flat end of the pool pump motor shaft to secure the shaft from rotating.

Step 11

At the pool pump impeller end, twist off the impeller, counter clockwise. You may have to use a strap wrench to gently free up the impeller.

Step 12

Now you will see the motor shaft seal. One half on the pool pump impeller and the other half in the seal plate on the shaft.

Step 13

Inspect the threads on the inside of the pool pump impeller. If these are badly worn, you will have to replace the impeller.

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Step 14

Stand the motor up on end and gently remove the white ceramic seal inside the seal plate. You may have to use a small screwdriver to gently pry out the seal. If the seal plate lifts off, it may be simpler to push the seal out of the seal plate from the other side.

Step 15

Set the new seal on the shaft inside the seal plate - white side up. Be very careful NOT TO TOUCH the white ceramic side of the seal with your hands. If necessary, gently seat the seal with the blunt end of a screwdriver.

Step 16

Grab the seal on the pool pump impeller and twist it off. Make a note of how the seal is positioned on the impeller so you know how to place the new seal. It is possible to place this seal upside down. Note: You may have to also have to remove the metal collar if the new shaft seal also has one. Several people have written in saying that the new seal won't fit because they were trying to place the new collar on top of  the old one.

Step 17

Now push the other half of the new seal onto the pool pump impeller. Place the new seal on in the same postion noted above. Again, DO NOT touch the bearing (top) surface of this seal.

Step 18

With the wrench securing the back end of the motor shaft, screw the pool pump impeller back onto the shaft (clockwise). Hand tight is sufficient.

Step 19

Inspect the diffuser gasket for wear. Replace if required. Put a thin coat of lubrication on the gasket.

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Step 20

Snap on the pool pump diffuser - no screws are required. Ensure that the part of the diffuser labeled "TOP" is aligned with the "TOP" labeled on the seal plate.

Step 21

Slip the motor assembly into the housing.

Step 22

Replace the four bolts evenly. If bolts were numbered 1 though 4, replace bolts in this sequence - 1, 3, 2, 4 - to ensure that the motor is set properly inside the housing. Loosely tighten bolts in this sequence, then go back and tighten them down again in this sequence. If pool pump has 6 bolts, replace bolts in this sequence - 1, 3, 5, 2, 4, 6.

Step 23

Replace the capacitor on the backside of the assembly. Make sure the plastic strip is in place between the clip and capacitor so that the capacitor does not short out.

Step 24

Replace motor cover and secure with two screws.

Step 25

Prime pump by removing strainer lid and filling strainer with water. Replace lid.

Step 26

Reset circuit breakers and start pool pump.

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(1 to 40 of 175)

 Posted: 3/25/2022 

My dad has replaced the shaft seal twice and says within four hours it tears apart the seal what is making it heat up he fits it down on the grooves just like it supposed to be and it locks in place but it’s still breaking apart after four hours

InyoPools Product Specialist  Posted: 3/28/2022 

The pump is running dry, or the seal is fouled during installation. If your pump runs dry (no water due to a priming issue), the friction between the two sliding pieces overheats and breaks the shaft seal. A single fingerprint can cause the fouling of a seal on one of the two smooth faces of the shaft seal. Substances like finger oil, lube, or dirt can cause the seal to break down.

 Posted: 3/24/2022 

Which way does the impeller Eye Seal go? There isn't even one shown on the impeller in this write-up. Mine has one...but nobody seems to know which way it goes. 1. Wide end against the impeller? or 2. Wide end Away from the impeller?

InyoPools Product Specialist  Posted: 3/25/2022 

The pump used in this guide is the Hayward Super Pump, which does not use an impeller ring. Impeller wear rings are not used in all pump designs. The wide part of the wear ring should face away from the impeller.

 Posted: 11/13/2021 

Really helpful tutorials, thanks. Trying to fix a leak, I replaced the ceramic shaft seal and 2 other gaskets. There was some leakage that might have reached the bearing. After reassembly, the motor hummed and would not start so I replaced the capacitor. Same thing. The motor is 2 1/2 years old. I can turn impeller by hand. Is it free? Well, it does not continue to spin once it is released…. Any ideas?

InyoPools Product Specialist  Posted: 11/15/2021 

First, I would check the voltage at the terminals. Then, if that passes, I'd check the phase windings. Here is a guide on How To Use a Multimeter to Test a Pool Pump Motor - Winding Resistance.

 Posted: 11/15/2021 

Thanks. I couldn’t exactly ID the “A” test point, it didn’t look like the point in the tutorial image. I’m testing a UST1102 (configured for 230v) and I see an unused terminal adjacent to L1/L2 and on the opposite side of the ground terminal (green wire). Could that be test point A?

InyoPools Product Specialist  Posted: 11/16/2021 

Which of the terminal boards on the following link most resembles what you have? Motor Parts - A.O. Smith

 Posted: 11/17/2021 

This one is mine: Terminal Board Assy w/ Voltage Switch - 628401-001. Is test point A the terminal by the voltage switch? Thanks for your patience!

InyoPools Product Specialist  Posted: 11/17/2021 

In Step 6, click the image to enlarge it. The diagram shows the terminal board you are using. Point A is the metal circle above the voltage knob.

Anonymous  Posted: 11/17/2021 

Thanks, I was able to confirm a dead motor. New motor has been ordered from Inyo!

InyoPools Product Specialist  Posted: 11/18/2021 

That's sad and good news all at the same time. But I'm glad we're were able to help you figure it out.

 Posted: 5/30/2021 

I replaced old motor with a Hayward 3/4 horse and seal kit. When I replaced motor and turned power on I get a soft hum for about 10 seconds and then it turns off. If I wait it will repeat. Only tried twice, any possible causes? Thanks.

InyoPools Product Specialist  Posted: 6/4/2021 

Did you confirm the motor is set to the correct voltage? Dual voltage motors come preset to accept 230 volts from the factory and need to be switched to 115 volts if necessary.

 Posted: 5/20/2021 

Thank you Your videos are great...we have told all out gang. Completely rebuilt our pool pump bearings seals and all. Keep up the good work. Note: you could include the rubber seals around the case ?? David

InyoPools Product Specialist  Posted: 5/21/2021 

Thank you, David. If you ar referring to the pump gaskets, the gaskets are matched to the pump housing and not the motor. So, if you purchase a motor/bearings, you are getting a product that can be used on dozens of different housings. There isn't a universal fit gasket kit, unfortunately.

 Posted: 4/19/2021 

I purchased a shaft seal SP1500KA seal kit for my Hayward power flo LX any the impeller seems to be frozen on and will not come off. Can you give me some advise on how to get it off.

InyoPools Product Specialist  Posted: 4/21/2021 

A strap wrench or channel locks are the best way to get the impeller off in one piece. If you cannot get it to budge, you may need to break off the impeller. If it comes to that, you can find a replacement impeller for your pump here, Hayward Power-Flo LX1580, 1520UN, 1680.

 Posted: 4/9/2021 

I recently had a leak coming from my shaft seal so I replaced it with a new one. When I started the motor up within seconds there was smoke coming through the pump basket. I took everything apart again and found the graphite seal was cracked and the ceramic one looked like the mechanical seal was rubbing against it with a lot of friction, also the seal plate that holds the ceramic seal looked a little melted and in worse condition then when I took it apart the first time. I've replaced many seals before so I'm quite positive I installed everything correctly. Any ideas on why or where this smoke is coming from? Was it a out of box bad seal maybe? I see a lot of people pointing to a bad motor but it doesn't seem to have any problems and also the smoke was from inside all the housing.

InyoPools Product Specialist  Posted: 4/9/2021 

Unless the shaft seal was defective out of the box, the only other thing I could think of is that part of the old shaft seal was still on the impeller. That could have caused some extra compression friction, leading to the failure. But that is just a guess on how a shaft seal could have caused this problem.

 Posted: 10/27/2020 

Great video! Made my seal replacement a piece of cake! Can’t thank you enough!

InyoPools Product Specialist  Posted: 11/3/2020 

Awesome! Thanks for reading

 Posted: 10/20/2020 

I brought a new Hayward replacemenpump, and I forgot to order the go-kit, and it started to leak. I ordered the go-kit and followed the instructions and now is working 100% thank you for the instructions they're very important. Thank u

InyoPools Product Specialist  Posted: 10/22/2020 

You are very welcome. Thank you for reading!

 Posted: 8/1/2020 

I just replaced my sp1607 pump with a v-grren pump. I got everything from you all and followed the video (very helpful!) for replacing everything. Now I'm getting a water leak from under the mounting plate. When I tighten the mounting bolts a bit more the leak stops. Does this suggest I may not have put the shaft seal on properly or just that I haven't sufficiently tightened the mounting plate bolts? All seals were replaced when I replaced the pump motor.

InyoPools Product Specialist  Posted: 9/1/2020 

There are only two gaskets that could cause a leak there, and that is the housing gasket or the shaft seal. I would break down the pump to make sure everything is installed correctly. While you have it apart, check for any cracks in the seal plate, just in case.

 Posted: 5/30/2020 

Made the mistake of not removing all of the shaft seal. I was lost until I ran into this. Thank you so much for saving the day.

InyoPools Product Specialist  Posted: 10/23/2020 

You're welcome! Thanks for reading.

 Posted: 5/23/2020 

This video was incredibly helpful. Thank you very much!

 Posted: 7/15/2019 

Changed shaft seal on Hayward super pump and still leaks what could it be.

InyoPools Product Specialist  Posted: 7/15/2019 

Either that shaft seal is not sitting correctly, or there is a crack in the seal plate. The seal plate is key 13, on this parts page Hayward Super Pump SP1600 & SP2600 Series

 Posted: 7/15/2019 

Thank you I will check seal plate and will get back to you thank you again

 Posted: 6/17/2019 

WARNING: Make sure you remove the hex screw from the impeller before trying to unscrew it off the shaft. The steps above do not mention this but Hayward pumps/motors have a hex screw that is reverse threaded and locks the impeller in place. I sheered mine off thinking it came off with the impeller. It does not. You must unscrew it (turn it to the right, not the left) before unscrewing the impeller.

 Posted: 6/15/2019 

I replaced a Go-kit 1 in a Hayward Max flo pump and when I went to use it water was coming out of the bottom near the motor, I followed the video and did every thing right I believe, never touched the white part and just to be sure I wiped it with a clean cloth prior to assembly. What do you sugest? buy another kit and try again? Or can a I salvage what I got and try again?

InyoPools Product Specialist  Posted: 6/20/2019 

I would take the pump apart to check the housing gasket; if that seal got pinched when assembling the pump the leak can resemble a bad shaft seal. 

 Posted: 5/14/2019 

I had a pump shaft seal go bad. I ran the pump a few hours with the seal leaking. I then replaced the seal, and now my pump is squealing when it runs. Do I need to replace the motor bearings and another shaft seal?

InyoPools Product Specialist  Posted: 5/14/2019 

Just to be safe, we would recommend replacing the shaft seal when you replace the bearings. The shaft seal you just installed may be ok but it would be a pain to rebuild the pump only to find out that it is leaking again.

 Posted: 4/10/2019 

I did the replacement and when I put it back together, I forgot to add water to the basket. Within seconds I smelled burning. I opened the basket area, and smoke came out. The seal has failed and water is coming out the bottom. Is it because of the dry start or did I do something wrong on the installation?

InyoPools Product Specialist  Posted: 4/10/2019 

Thee pump running dry caused the seal to fail. Installing the seal incorrectly wouldn't have caused the pump to smoke.

 Posted: 2/5/2019 

I absolutely cannot get the white ceramic seal with rubber ring to fit in. Seems like everyone else is not having a problem but mine is too tight to even start in the cavity. Why is mine not fitting?