top of page

How To Fix Leaking Pool Pump | Pentair Challenger Motor Shaft Seal Replacement & Housing Gasket Leak

The pool pump shaft seal on our neighborhood pool started leaking tons of water. Once we got the right size seals, it was a fairly easy repair.

Watch the full video on how to fix the leaking Pentair Challenger pool pump:

The pool pump housing is a Pentair Challenger mated to a large strainer basket. The pump motor we are using is a Century Centurion Model B1000

The motor shaft diameter is 5/8in

Pentair Challenger Pool Pump seal kit

Leslie's Pool Supply Repair Kit #65005 (Which was only available at Leslie's Commercial store)

Shaft Viton Pump Seal Part PS200V Leslie's Part #40677 (UPC Code: 810379030078 )

Buy from Amazon -

Diffuser O-ring Leslie's Part # 66518 (UPC Code: 810379030375 )(Compare to PAC FAB PENTAIR #355331 or ALADDIN O-421 )

Buy from Amazon -

Housing Gasket Leslie's Part # 608185 (UPC Code: 810379030467 )(Compare to PAC FAB PENTAIR #355329 or ALADDIN O-506 )

Buy from Amazon - or

Strainer Basket Gasket (AM GSKT TR100C LID 152509 Pentair 152509 8-1/2" O Ring Pump/Filter) Leslie's Part # 44562

Buy from Amazon -

After replacing all the seals and gaskets on the pump, the pool pump motor ended up also needing its bearings replaced because water had gotten past the multiple seals and into the bearing. The motor is a Century Centurion B1000. It was impossible to find out what size bearings were used. None of the pool companies knew, and I also contacted the manufacture, which led me to their local service center, who spent some time looking for documentation that had the bearing sizes, and they could not find it either. Finally, the bearings seized, the pump motor stopped, and we had to remove and take it apart to determine the bearing dimensions.

The front bearing is an NSK 6304DU (Replaced with a 6304-2RS) designed for a 20mm shaft -

The rear bearing is an NTN 6203LH (Replaced with a 6203-2RS) designed for a 17mm shaft -

The motor must be completely removed and disconnected from the pump and power. The impeller has to be taken off the shaft. There's a rubber ring around the shaft that is supposed to sling water away from the shaft. Remove that. Then there's a metal washer pressed in. Use a screwdriver to remove that by prying through the housing drain hole under the shaft. Behind that, you'll find another rubber ring. This is the last line of defence to keep water out of the motor housing. Remove that too. Then there's a screw that holds the bearing that must be loosened.

Mark the positions between the front, center, and back motor housings using a marker or tape to make sure that you can easily realign them when reassembling.

There are 4 extremely long screws on the back of the motor that holds it all together. Carefully unscrew those. Some may need to be worked back and forth a little due to corrosion.

The front of the motor housing was stuck to the bearing/shaft so I had to use the gear puller to remove it.

The bearing was completely shot and damaged. The size was barely readable. It was marked NSK 6304DU.

I tried to use the gear puller to remove it, but even after applying an enormous amount of torque using a 1/2in extension ratchet, it would not move.

Ultimately I had to remove the outer bearing race, and use a small abrasive cut off wheel to cut a slit in the bearing to be able to open it and remove it from the shaft. That's when I saw that the bearing had lightly stir welded itself to the shaft, thus explaining why the puller could not remove it.

Surprisingly the repair worked. The motor sounded just like new and we saved over $700. Great Success!

The products shown here were purchased by me with the intent to use them. I did not receive any free items, and I am not being paid or compensated for this review. The video, description, and comments may contain affiliate links. If you click on a link, I may receive a commission. Money earned helps to support my channel and bring you more informative videos about engineering, crafting, and DIY


Recent Posts
Search By Tags
Follow Us
  • Facebook Basic Square
  • Twitter Basic Square
  • Google+ Basic Square
bottom of page