How To Change Pool Pump Gaskets

This guide provides a step-by-step procedure for replacing pool pump gaskets. 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.

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.

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.

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.

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.

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.

6. Now pull the assembly apart from the housing.

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

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

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

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.

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

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

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.

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

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

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.

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

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.

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.

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

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.

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.

If you have any other questions about pool and spa products please do let us know - we are here to help! 

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