Possible air leak in the vac suction line?


Jul 12, 2015
Austin, TX
My pool has a dedicated vac port on the pool wall


with 1.5" pipe going all the way to the equipment with a T


VAC - vacuum line 1.5"
SK - skimmer line 2"
DR - bottom drain line - 2.5"

I never had much luck with Zodiac MX6 pool cleaner running at the right speed off vac port without introducing a lot of bubbles/air in the skimmer. To get it moving close to the speed in the manual (which would require about 25gpm per manual) I would have to close off quite a bit of both skimmer and drain lines which in turn brings a lot of air into the pump. I thought it is just pipe diameter is too small for the length (about 50') and pump starts sucking air through all the gaskets.

But recently I noticed something odd - if I leave all three lines open (so all three T valves handles pointing down) AND remove vacuum from the wall (which makes vac line plugged). I.e. vac line is plugged on the pool side and open on the pump side alongside with skimmer and drain lines. After pump is shut off - I see bubles coming out of the closed vac port in the pool.

That made me think that there is actually an air leak somewhere in the vac line. Most of the vac line is under the concrete deck. I already hosed everything near pool equipment trying to see if it will eliminate extra air - zero changes.

Any ideas what I can do to confirm vac line is tight or sucking air without diging it out? Anything else you guys might think that could possibly bring air into plugged on the pool side vac line?


TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
Morris Cnty NJ
Looks like you could pop cover off the 3way and open it up. Insert a test plug there and seal it. Remove vac fitting after lowering water and pressure test it with a low psi to not blow plug out. You will know right away if its leaking
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