How To Replace Pool Pump Gaskets


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If you have a leak spraying out of the seal between the pool pump housing and the motor assembly, you probably need to replace the housing gasket between the two units. We recommend that when you pull the pool pump motor assembly to replace this gasket, you also replace the diffuser gasket within the motor assembly.

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Things You'll Need


Step by Step


Step 1

Before you pull the pool pump apart, check to make sure the pump bolts are secure. The pool pump is held together with six bolts. Hand tighten these bolts with a socket wrench. If one or more of these was loose, you might have found an easy fix to your leak.

Click Here to Find Your Pump's Replacement Gaskets 

Step 2

Assuming that you could not fix your leak by tighening the bolt, your first step is to order gaskets for the pool pump. You should have these on hand before starting your pump repair. You can order the pool pump gaskets separately or order a gasket package, GO-KITS, that includes the four gaskets and seals required for a general pump repair. This How To Page addresses replacement of the housing and diffuser gaskets. Replacement of the strainer gasket and shaft seal are covered in other How To Pages. Note: These gaskets are generally unique to the make and model of the pump, e.g. this set will only fit the Hayward Super II Pump. Order the set of gaskets specified for your pump's make and model.

Step 3

Your pool pump gaskets have been sent to you. Check to make sure you have the right gaskets. You are now ready to pull the pump apart. First, turn off the power to pump to stop suction.

Step 4

Next you will have to relieve the pressure that has built up in the pool pump and water line. Note the pressure on the pressure gauge. It will typically read between 15 - 20 psi. Note this value for future reference when you restart the pump. To relieve pressure turn the air relief valve on top of the pool filter counter clockwise. Water will spray out initially as you see the pressure on the pressure gauge go to 0 psi.

Step 5

To extract the motor pump assembly from the pump housing, first remove the six 9/16" bolts that bind the motor pump assembly to the housing. Keep track of the washers.

Click Here to Find Your Pump's Replacement Gaskets

Step 6

Now pull the assembly apart from the housing.

Step 7

Check to ensure that the pool pump diffuser came out with the motor assembly.

Step 8

Pull the pool pump diffuser away from the motor assembly. It should snap off easily.

Step 9

Turn the pool pump diffuser over and ensure that it is free of debris.

Step 10

Check that the pool pump impeller is not clogged with debris. Pull any debris out. If necessary, use a stiff wire or small screwdriver to work the debris out of the slots.

Click Here to Find Your Pump's Replacement Gaskets 

Step 11

Slip the old diffuser gasket off the pool pump diffuser and replace it with the new gasket.

Step 12

Ensure that the new gasket is seated to the stop. Put a thin coat of lubrication on the diffuser gasket.

Step 13

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 14

Pull the housing gasket out of its groove in the pool pump housing.

Step 15

Clean out the groove in the pool pump housing assembly. A small screwdriver covered with a layer of cloth works effectively.

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Step 16

Insert the new housing gasket in its groove. These new gaskets are tight. You may have to have someone hold half of the gasket in the groove while you are inserting the other half. Put a thin coat of lubrication on the gasket. Use a good pool parts lubrication. Some common lubricators, like Vaseline, will deteriorate gaskets.

Step 17

Clean off the surface on the seal plate that will come in contact with the pool pump housing gasket.

Step 18

Replace the motor assembly back into the pump housing. Insert and tighten the 6 bolt that bind the motor assembly to the pump housing. To ensure that the motor assembly seats properly inside the housing, loosely tighten bolts in alternating sequence - 1,3,5,2,4,6, then go back and tighten them down again in this sequence. This is important for proper operation of the pool pump. Hand tighten firmly.

Step 19

Since the water drained out of the pool pump when you opened it up, you will have to prime the pool pump before turning it on. Open up the strainer and fill the strainer pot with water. Clean any debris out of the strainer basket while it's open. Close strainer lid securely.

Step 20

Turn on power to the pool pump to restart pressuring the system.

Click Here to Find Your Pump's Replacement Gaskets 

Step 21

The air relief valve on the filter should still be open. As the pressure builds, air will be released through the relief valve. When water starts to spray out of the valve, turn the valve clockwise to close it.

Step 22

Check that the pressure gauge reads at your operational value (see step 4). This value varies from system to system. You should see water flowing though strainer.


(1 to 19 of 19)

 Posted: 8/30/2020 

Replaced pump housing gasket and diffuser gasket, still leaking in same place at the bottom. I greased the gasket with the magic lube and cleaned the surfaces very well, did the alternate bolt tightening. what next?

InyoPools Product Specialist  Posted: 8/31/2020 

Sounds like you need to replace the pump's shaft seal. What Shaft Seal Do I Need? – – DIY Resources

 Posted: 9/5/2020 

Is there a how to on replacing the shaft seal. I purchased the GOKIT2, i believe this came with new one?

InyoPools Product Specialist  Posted: 9/8/2020 

We do not have a guide that talks specifically about disassembling and replacing the gaskets on a Hayward Super II. But, you can use a combination of this guide, How To Use a Tune up / GO-KIT, and this guide How To Replace the Motor on Your Pool Pump to get the general gist.

InyoPools Product Specialist  Posted: 6/9/2017 

Terry - It does not matter where you start the sequence. You are just trying to apply pressure evenly.

 Posted: 6/9/2017 

The alternating sequence for the 6 bolts on the Hayward Super Pump 2 for the housing gasket replacement of 1,3,4,2,5,6 where is number 1 bolt located? Or does it make any difference where you start?

InyoPools Product Specialist  Posted: 6/21/2016 

jerseyandy - Yes, it is possible to overtighten the bolts. I would take the motor assembly out again. Check for cracks in the new gasket. Check for cracks in the housing around the gasket groove. Make sure the groove is clean. Re-clean the area on the seal plate of the motor assembly where the gasket comes in contact with the plate. Put a thin layer of silicon lube on the gasket. When you bolt the assembly to the housing, alternate the bolts from one side to the other to ensure a good seal. Hand tighten until the bolts are snug. If you still have a very slow leak - 2 drops a minute- you can probably live with that. You may have to replace the housing if the leak gets larger.

 Posted: 6/20/2016 

I replaced the gasket between the pool pump housing and the motor assy with a brand new gasket from the GoKit for my Hayward Super Pump 2. Yet, i have a very slow drip at the bottom. (1 drop every 20-30 sec)...could it be overtightened??. I just recently installed a new motor assy and changed all the shaft seal, impeller seal, that all is fine...just an issue with the gasket

InyoPools Product Specialist  Posted: 7/21/2013 

ramsey - See our guide on "How To Replace A Pool Pump Impeller". It should be close enough to you motor design to help you.

 Posted: 7/20/2013 

How do you remove the impeller from the motor shaft of an Emersom HP2?

InyoPools Product Specialist  Posted: 7/2/2013 

Shell - Your motor probably has a little corrosion around the seal. I would get a rubber mallet and tap it around the circumference of the motor to loosen it up a little.

 Posted: 7/1/2013 

Stuck on step six. Sigh. Hayward RS. Removed six bolts. Motor still won't pull off. I've watched video after video of people popping that sucker right off after removing the bolts, just as you describe here. What am I missing??

 Posted: 5/4/2013 

Great DIY instructions! Step 14 was probably the hardest part of the whole operation.

InyoPools Product Specialist  Posted: 2/11/2013 

confused - If you haven't already replaced your housing gasket, do that now. Make sure the gasket seats properly. When you tighten the clamp, it sometimes helps to tap it gently to distribute the pressure all around the clamp - clamps tighter. Lastly look for cracks in the housing. Occasionally it has to be replaced.

 Posted: 2/10/2013 

We just replaced our motor, pool seal, and o-rings on our Challenger Pentair 3/4 hp pump. My question is that it is still leaking at the bottom of the clamp. Any suggestions?

InyoPools Product Specialist  Posted: 8/7/2012 

cruzer0984 - Turn your motor off and don't run it while it's wet. Hopefully it hasn't shorted out. Fix the leak that is spraying your motor - probably the shaft seal - then see if your motor is not permanently damaged.

 Posted: 8/6/2012 

pump got wet now i turn on and it starts to smoke from bcak of motor....

 Posted: 6/21/2012 

Thanks, how do you stop the diffuser gasket from getting pushed back when you re-assmble it?

 Posted: 1/2/2012 

I replaced a couple of my pool pump gaskets and it stopped the leak. Thank you for the information