Pump housing crack


Apr 22, 2011
Gilbert, AZ
This forum has provided so much help to me over the years, and I wanted to share an experience with my pump housing that can hopefully help someone else down the road.

A few months ago, I noticed a few things for the first time. My filter pressure was about 5psi low, my pump sounded louder than normal, and my strainer basket showed what looked like smoke swirling inside of it. The guy at the pool store said it was probably very small "micro bubbles" that was causing what looked like smoke, and I initially thought I might have a very minor suction side leak. I spent a lot of time with all of the suction side leak detection tricks found on this forum, but could never find any suction side leak.

I did not think I had any issue with the pump housing, because I had no visible water on the pressure side of the pump, and ran water over every inch of the housing outside of the suction side of the pump. I was confident I had no housing leaks to the outside of the pump. Finally, I decided to drain the pump again and inspect the housing again. Sure enough, I found a 3" vertical crack in the side of the housing towards the lower end of the strainer basket, but it did not go outside the pump. I ran the pump with the basket removed, and saw a massive amount of water rushing into this crack.

It turned out that the crack was between the high side of the pump housing and the low side of the pump housing. This is what was causing the "smoke" appearance, causing the pump to be loud, and dropping the pressure in my filter.

I think the Hayward Northstar has a very unique housing design, so not sure how many other pumps would have a similar issue with a crack that goes from the high to low side (if I recall, most other pump motors bolt directly to the housing in a way where there is very little surface area of housing between the high and low side compared to the Northstar)

I added two part epoxy to the crack on both sides, and that immediately quieted my pump, pump basket is crystal clear now, and my filter pressure is back to normal levels. I assume this will not be a long term fix, so currently shopping variable speed pumps, but very relieved to have found my issue, and I hope someday this can help someone else diagnose a similar problem.