Replaced cracked skimmer, now it leaks


May 30, 2010
AG 24' Round pool
Deck fence surrounding pool so really hard to work on both sides of pool for 1 person.

I had a steady leak but not huge in the old cracked skimmer mouth (about an ounce a minute). I got a new Hayward skimmer (SP1091WM) and my friend offered to help saying it would take about 10 minutes! I'll just get to the juicy details.
The friend told me we didn't need to lower the pool water and by using a large plastic bin top he could hold most of the water in as we removed the old, and reattached the new skimmer. Needless to say this "plan" was doomed to fail. The gushing water made the gasket move so much and alignment impossible and I ended up losing about 2 thousand gals anyway and finally, using the center drain, lowered the pool just below the skimmer after the frustrating first attempt. Now the "Butterfly" gasket that came w the skimmer would not fit as intended because the skimmer cutout was smaller than the gasket inner dimension. Yeah, the cutout is too small and the gasket would bunch up. The pool is old. I know the gasket is supposed to fit perfectly in the hole cutout so one side of the gasket is inside the pool between the faceplate and the the other on the outside between the skimmer mouth and the pool side. This would've been great and would make the job much easier. This it would not do, so I had to cut the "butterfly" into 2 separate gaskets and try to keep them in place, one on each side, during installation. Now we attempted to attach the body and faceplate with the gaskets aligned. We had to use the old holes drilled in the metal sides (and lining) for the old skimmer and they seemed to line up fine but sometimes it was really hard to "find" the holes in the skimmer body. We used nails as guides to align the holes right and removed the nails one-by-one to screw in the screws. After many attempts to get the gasket aligned perfectly and the holes all lined up perfectly it is now tightly screwed in. After splashing up water to test the seal it is leaking on the lower corner. This leak is much bigger than the one I started to "fix" This is much harder than I thought it would be.
1. (Observation) The included instructions are only for a new installation in a new pool. The "Butterfly" gasket is used with only perfectly cut wall holes and I should've gotten separate (wider) gaskets.
2. The gaskets (after separating them) are really hard to keep aligned (hole on hole) , and they are a bit narrow.
3. Should I have used some silicone or glue or something (anything) to keep the gaskets in place on the parts or on the pool wall? They may have slipped out of alignment, there's no way to see between the housing and the pool side to be sure!
4. My reaction (untested as I don't want to waste another 2 thousand gallons in case I have to completely redo this) was to tighten the dickens out of the faceplate. How tight should the screws be, til you can't turn anymore, because that's what I did?
5. Anybody know if I run beads of silicone (around the inside and outside of the pool) skimmer, will it hold water? In other words will the silicone make up for an unaligned gasket?
I wish I'd have told my friend "Let's leave it be".
Anybody who's "learned by doing" concerning replacing a skimmer who can give tips/advice, I'd appreciate it.


Well-known member
Mar 13, 2009
Buy a new gasket and call the pool company to change the unit for you. You will be money ahead.