PacFab Challenger pump leaks at band clamp -solved

lcoleary

Member
Dec 10, 2019
7
Austin TX
I've had a leak from this pump since I purchased my house and have not been able to determine the cause. Had two different pool repair companies come out under my home warranty (replaced seal once and housing o-ring once) and leak would stop for a bit but then start up again (leaking water where the band clamp connects the volute to the front housing).

Eventually I had a squealing motor and decided I was going to tackle this repair myself to fix it for good. Squealing was from the motor and bearing replacement was needed. Upon taking the pump and motor apart, there was significant wear on the diffuser and impeller where they meet each other. All parts replaced on this job were: seal, impeller, diffuser, two motor bearings, o-rings for diffuser and front housing.

Put it all back together and still having a leak at the band clamp. Bought another o-ring, and replaced and still leaking. Took the whole thing apart again and checked housing and volute for cracks - no problems seen on those parts. Bought new band clamp - still leaking.

At my wits end when I found this post :

OK, here is the answer to this problem. There is nothing wrong with the volute, nor the SS clamp band. The online source that I purchased the seal kit from provided the volute seal, indicating that it was a replacement part for Pentair Challenger pumps, BUT IT IS NOT!!! As I previously alluded to, the previous gasket had a SQUARE CROSS SECTION, NOT A ROUND ONE. The new replacement was a ROUND CROSS SECTION, which I assumed would form fit to the square groove in the volute. WRONG! You all probably knew that, but I did not...
My reason for posting my results here to to spare some other person the hassle of buying something that doesn't work, then the insult of being ignored when a problem that the company has created has no resolution.
My advice:
AVOID CHEAP ONLINE SOURCES THAT ADVERTISE A GENERIC, "UNIVERSAL" FIT FOR YOUR EQUIPMENT AND GO INSTEAD TO YOUR MANUFACTURER. THE PRICE MAY BE HIGHER, BUT THE PART WILL WORK AND YOU DONT HAVE TO SPEND A MONTH OR SO LOOKING LIKE A IDIOT WONDERING WHY THE PROBLEM YOU ALREADY "FIXED" STILL NEEDS FIXING!!!
Guess what? that's my problem!! exactly! the o-rings I bought were both round and not square and they don't form a proper seal at the band clamp. So, returning the new band clamp, and seeking refund for the wrong o-rings. Feeling real good about this rebuild because the motor and pump are just humming along beautifully.

The correct o-ring is Pentair #355329 front housing o-ring! make sure it looks square not round if you get it in a GoKit, but I recommend just getting the individual o-rings that you need INSTEAD of a GoKit as I only needed the front housing o-ring and the diffuser o-ring.

posting this for anyone else who just couldn't figure out why, after replacing multiple parts, there was still leaking around that band clamp.


UPDATE: I'm attaching pictures of the correct o-ring. Here is a link to my video explanation of this post where I show the incorrect o-ring :


Good luck and happy pool maintenance :)
 

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lcoleary

Member
Dec 10, 2019
7
Austin TX
I've had a leak from this pump since I purchased my house and have not been able to determine the cause. Had two different pool repair companies come out under my home warranty (replaced seal once and housing o-ring once) and leak would stop for a bit but then start up again (leaking water where the band clamp connects the volute to the front housing).

Eventually I had a squealing motor and decided I was going to tackle this repair myself to fix it for good. Squealing was from the motor and bearing replacement was needed. Upon taking the pump and motor apart, there was significant wear on the diffuser and impeller where they meet each other. All parts replaced on this job were: seal, impeller, diffuser, two motor bearings, o-rings for diffuser and front housing.

Put it all back together and still having a leak at the band clamp. Bought another o-ring, and replaced and still leaking. Took the whole thing apart again and checked housing and volute for cracks - no problems seen on those parts. Bought new band clamp - still leaking.

At my wits end when I found this post :



Guess what? that's my problem!! exactly! the o-rings I bought were both round and not square and they don't form a proper seal at the band clamp. So, returning the new band clamp, and seeking refund for the wrong o-rings. Feeling real good about this rebuild because the motor and pump are just humming along beautifully.

The correct o-ring is Pentair #355329 front housing o-ring! make sure it looks square not round if you get it in a GoKit, but I recommend just getting the individual o-rings that you need INSTEAD of a GoKit as I only needed the front housing o-ring and the diffuser o-ring.

posting this for anyone else who just couldn't figure out why, after replacing multiple parts, there was still leaking around that band clamp.

Good luck and happy pool maintenance :)
Just thought I'd mention that total cost for all necessary parts was $101 - $80 for the impeller and diffuser, $12 for the correct front housing o-ring, $9 two motor bearings plus sweat equity :) I am confident this pump will last for years and I should just be replacing the seal about every 2-3 years.
 

lcoleary

Member
Dec 10, 2019
7
Austin TX
Just want to add that the reason I didn't catch this when I first took apart the pump was that there was a round o-ring in there so it didn't occur to me that it was incorrect when I purchased a replacement. There were other parts missing inside my pump (impeller screw and one of the screws holding the seal plate to the pump housing) and I'm not sure how those went missing, but it was obviously from someone working on the pump prior to me and could have been previous home owner or even one of the two pool repair companies that came out and worked on the pump under my home warranty. So, don't trust that your pump has been worked on properly and verify all replacement parts yourself ideally against a parts picture list online when you take it apart.
 

workedonthousandsofpools

In The Industry
Jan 9, 2020
1
Phoenix
Challenger pumps always used round seal plate o-ring which have always been tricky to keep in place when pump halves are joined back together, many years ago a quad-ring became available for these pumps that solved that problem as they stayed in the o-ring channel without having to put lube all over it in order to keep it in place for a split second to join the pump halves, it is almost impossible to keep the round o-ring in place without lube when joining pump halves.
When these pumps were assembled in the factory, I bet the halves were joined in an upright vertical position to keep the o-ring laying flat.

The quad ring was something only a repair tech usually knew existed as an option over the round style, because if you asked for a Challenger seal plate o-ring, and didn't specify the square/quad ring, they would just give you the round one.
So ..it's not that the round style is wrong (it's actually the right part) it's just that the quad ring is much better than the round because it stays in the channel without lube,
 

lcoleary

Member
Dec 10, 2019
7
Austin TX
Thank you, workedonthousandsofpools! That is a very informative comment. In my case, I used LOTS of lube - I cleaned the channel completely, lubed inside the channel, then placed the new round o-ring, then put lube generously with fingertip on top of the o-ring, then pushed the two housing pieces together and installed the band clamp. Still had a leak. Then I got another round o-ring and a new band clamp and did the same procedure - still had a leak. It wasn't until I saw the post about the quad (square) o-ring that I realized that's what I needed and when I put that in with my original band clamp that my leak was solved. Immediately and holding up perfectly weeks later. Therefore, IMHO, the quad (square) o-ring is what is needed when replacing this part and a pool owner is only asking for trouble when they use a round o-ring in the front housing.

Thanks for your clarification and I hope that this thread will help other pool owners like myself that have this problem, especially after replacing multiple parts. In my case, my impeller and diffuser were worn down where they join together, so I replaced those two parts as a matter of good practice.