Air in returns with pool cleaner running.

[DRX]

Hello
I have air in one of the returns when my pool cleaner is running. The pressure gauge on the filter drops from 80kpa to about 30 kpa when the pool cleaner (Baracuda Classic) is connected. Before I noticed that air in the returns the drop in pressure was to about 50kpa with the Baracuda running .
Also I have noticed that the pool is loosing water.
I suspect I have a leak , can anyone advised if its suction or return? Why is the air apparent in the return when the pool cleaner is running and not at other times.

Thanks
DRX

 

[Bama Rambler]

Unless I'm mistaken, the Barracuda is a suction side cleaner. That being the case, it will lower the filter pressure when running but raise the suction head. If you have a suction side leak then running the cleaner will make it worse and cause the air in the returns like you're experiencing. Everything points to a suction side leak. The pump strainer basket is a common place. Remove and clean the o-ring & groove and lube it with silicon pool lube, then reassemble it before you do anything else.

Oh and by the way, Welcome to TFP!