Just purchased a Hayward Pool Vac Ultra with the Vac Plate.

Installed everything and it worked great for about 30 minutes, and then the
cleaner started to float off the bottom of the pool. It seems small bubbles
were forming on the hose and cleaner unit. Shaking the bubbles loose sank
the cleaner back to the botton, and it continued roaming around for another
30 minites or so.

The manual states that this can be caused by stressing the suction side so
that air might be entering. A quick look into the trap lid at the pump
confirmed this. In addition, whenever I would shut off the pump motor, I
noticed a drop of water coming from a pipe joint about six inches from the
suction side of the pump (also, air bubbles were coming out of one of the
pool water jets).

So I fixed the leak, and now the cleaner stays at the bottom and is working
great.

My question is:

How would a suction side air leak near the pump cause air bubbles to form at
the cleaner and hose?

Thanks for the physics lesson,

Mike