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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InyoPools Product Specialist  Posted: 2/24/2013 

2428dakota - No, the motor shaft seal is different for each pump. Half of the seal is mounted into the seal plate of the pump. After you have identified what pump you have by manufacture and model, go to our website and look up the replacement parts for that pump. It will list the specific shaft seal required for your pump.

 Posted: 2/20/2013 

I am replacing my main seal shaft on my AO Smith motor. Is this a standard part that is the same on all pool pump motors? I have looked everywhere for an AO Smith part, to no avail.

InyoPools Product Specialist  Posted: 1/7/2013 

Chuck - Unfortunately the only way to remove the shaft seal is to remove the motor. The shaft seal is on the shaft of the motor.

 Posted: 1/6/2013 

I'm replacing a seal on an older Hayward Powerflo pump. Is there a way to get the ceramic part out without removing the motor? The motor bolts are corroded stuck. Alternatively, can I replace the black part of the seal without replacing the ceramic white part if the white part seems fine?

InyoPools Product Specialist  Posted: 10/19/2012 

istillhatepoolpumps - The V-shaped part on the electrical end of your pump is called a stationary switch. If you have a AO Smith motor, the part number for this switch is 5270-64.

 Posted: 10/18/2012 

What is the "V"-shaped part that sits right beside the capacitor and what does it do? Because I'm pretty sure we broke it when trying to secure the motor shaft. Can it be replaced?

InyoPools Product Specialist  Posted: 10/15/2012 

Ihatepoolpumps - Check to make sure the shaft spins freely. If not your bearings may be bad or your shaft seal may not be seated completely and may be binding. Also check that the leads to your capacitor did not come lose when you moved it to get at the back end of the shaft. Then check to make sure your capacitor is still good. See our guide on checking and replacing a capacitor.

 Posted: 10/14/2012 

Okay so we did all of this step by step. When we put the back on we flipped the breaker back on and turned the pump on. All it did was give us a slight buzzing noise and the pump never kicked on. Is it possible that the capacitor just needs to recharge? Or did we definitely disconnect a wire or mess up something else electrical?

InyoPools Product Specialist  Posted: 9/26/2012 

jose - Your motor bearings may be going and generally when the motor gets to that point, people replace the motor. Also check to make sure something is not caught in the impeller that might be rubbing on the inside of the motor.

 Posted: 9/25/2012 

I have a Super pump from Hayward and I notice a noise like from the pump because the motor was working good.then, I turn off the motor,but I dont know what it can be.I am going to do step by step the how to replace...but I dont know what it can be or that I can be aware of.thank you

InyoPools Product Specialist  Posted: 9/16/2012 

Manfred - Looks like you have the correct shaft seal, but it looks like its the generic version. You might try the OEM seal and see if you have better luck. Our PN is SPX1600Z2.

 Posted: 9/13/2012 

I have a Hayward Super Pump 1 1/2 hp since June 2009. After two years it started leaking between motor and pump housing. I replaced the shaft seal as disribed without touching the ceramic parts and the impeller. The pump was running well and started to leak again after 3 month. The shaft seal was worn. I replaced it and it worked fine again for another 3 month and so on. Now it's leaking again and it would be the 4th shaft seal to be replaced. What could be wrong? The pump and motor is otherwise running well and makes the regular noise. The shaft seal is from U.S.Seal MFG.PS-201. Could you please help me out? I'm getting tired of replacing the shaft seal every 3 month. Thank you.

Anonymous  Posted: 8/31/2012 

Really hated to get started on this but after reviewing the instuctions even though I really didn't want to do it it was a breeze. I'm no mechanic but it was great after looking at these instructions a couple times.

InyoPools Product Specialist  Posted: 8/24/2012 

haden - 30 years is a very long lifetime for a pump. It is probably time to buy another one. The new designs are generally more efficient so you will probably save money in operating costs.

 Posted: 8/24/2012 

I have replaced the shaft seal twice on my pack fab challenger I have not touched seal,used lub provided by pool supply store, and it continues to leak even with two different motors. I cannot see any cracks in housing. do I need to buy a new pump? this one is over 30 years old

InyoPools Product Specialist  Posted: 8/22/2012 

stuck impeller - If you have an old pump that has never been serviced, it may be corroded and parts may not come apart as easily as shown here. Try using WD-40 or a similar product to help free up the parts. Also be aware that some impellers are also held on with a set screw that has to be backed out before the impeller will come off.

Anonymous  Posted: 8/20/2012 

What do you do if the impeller doesnt come off as simply as your pictures show.Your pump looks as if it has been taken a part many times mine isnt painted like yours.

 Posted: 7/25/2012 

Fantastic diagram(s) and instruction, thanks for this site, it saved me a ton of trouble and money.

InyoPools Product Specialist  Posted: 7/15/2012 

Paul - Yes the black shinny surface of the shaft seal on the impeller side is supposed to come in direct contact with the white ceramic surface of the shaft seal in the seal plate side.

 Posted: 7/14/2012 

I have a question:
Replaced the seal in my Hayward super pump. However I am confused on which way the shaft seal is to be seated in the seal plate. One side of the ceramic is grooved. Is this side exposed or is the grooved part facing the rubber gasket. In other words when you look at the seal plate is the shaft seal surface smooth side up or groove side. ALSO on the seal assembly with the spring that goes on the impeller, is the black plastic piece supposed to be in dirrect contact with the white ceramic shaft seal? If so I cannot understand how this would not cause a leak. Thank you so much in advance for your response and time.
pittsburgh, pa


InyoPools Product Specialist  Posted: 7/7/2012 

George - I would take the motor out of the pump and check that the impeller is not broken or clogged with debris that jams the motor. It the motor shaft moves easily when you have it out, you may have a bad motor that will have to be replaced.

InyoPools Product Specialist  Posted: 7/7/2012 

Greg, The shaft seal may not be set squarely. I would take the seal out again and reset it. Also make sure you have the correct shaft seal for your pump. They vary by pump manf and model. The impeller should not be an issue.

InyoPools Product Specialist  Posted: 7/7/2012 

UST1152 motor - It's difficult to assess your problem without knowing the pump mfr, but on most pumps one half of the ceramic shaft seal is pressed into the seal plate and has to be pressed out. And generally the only other seal around this area is the housing gasket. See our guide on How To Replace Pool Pump Gaskets.

 Posted: 7/6/2012 

motor stop and jam what could that be how do I fix it?

 Posted: 7/6/2012 

I just replaced the pump seal on my Hayward 1 HP pump and now it only hums when I try to get it going. Shaft is very stiff to turn by hand. What could be the possible problem(s)? One thing I did notice is when I manually turn the shaft it seems to tighten and or loosen the impeller.

Anonymous  Posted: 7/2/2012 

I have a 1.5 HP AO Smith UST1152 pool pump; it is leaking underneath/beind the square part. I tried taking it apart...I see a ceramic plate but cannot understand how it comes there a larger seal underneath that could be my problem; and if so how do I get to it?

InyoPools Product Specialist  Posted: 6/1/2012 

Cynthia - I wouldn't bother replacing the shaft seal until you see water dripping out of the bottom of the motor.

 Posted: 5/29/2012 

If I don't have any problems, do I ever need to replace the motor shaft seal?

InyoPools Product Specialist  Posted: 5/8/2012 

Yes, you should lubricate all the gaskets with a silicon lubricant. But do not lubricate the shaft seal.

Anonymous  Posted: 5/7/2012 

Should I use lubricant on the rubber parts of the seals? Do I lube the shaft?


InyoPools Product Specialist  Posted: 4/30/2012 

A new motor will almost fall apart after you take the bolts out. Make sure you got all the bolts. Some pumps have six and the bottom ones are sometimes had to see. If it's an old motor, it may be corroded a little or there's a chance that the diffuser is broken and hung up on the impeller.

Anonymous  Posted: 4/29/2012 

I tried to remove motor but found it difficult to pull out after the bolts where removed. It felt like it was binding on something. I tried using a crowbar but it still difficult to remove? What do u think the problem is?

InyoPools Product Specialist  Posted: 4/9/2012 

ina - Yes a broken impeller will prevent water flow and would have to be replaced. You should be able to replace the impeller without disturbing the shaft seal.

 Posted: 4/8/2012 

will a broken impeller stop the pump from pumping water would the mechanical seal still be okay that was replaced 3 months ago

InyoPools Product Specialist  Posted: 2/23/2012 

Ed - The Badu Jet is manufactured by Speck Motors. You might give them a call at 800 223-8538 to see what kind of installation support they have in Vermont.

 Posted: 2/22/2012 

I have a Badu jet as a jacuzzi and there is leak that I cannot fine. The pump is not the problem. I think the housing of the Badu jet maybe the problem its quite old and needs replacement. Is there anyone in the stae of Vermont replacing and installing new Badu jets?

 Posted: 1/14/2012 

I replaced my seal and all gaskets but it still leaked. I noticed the original factory installed impeller was all plastic. I bought a new one which has a brass insert. This finally fixed my leak.

 Posted: 1/2/2012 

Thanks for the information on how to replace a pool motor shaft seal

 Posted: 9/2/2011 

thank you very much , pictures where very helpful

 Posted: 7/2/2011 

My pump was leaking and i replaced all the o-rings and it still leaked. I replaced the motor shaft seal and this took care of the leak. The instructions were great.