Problem Air Leak - Need Help!

I would really like this forum's help, I've read everything online and stumped folks at 2 different local pool supply stores. My issue is an air leak. I know I have a leak because air accumulates in the filter (I release air all the time) and there are small bubbles in the salt cell (it's clear so I can see through it) and coming out of the pool returns.

Suction Side:
1. I replaced the basket lid gasket
2. I replaced the gaskets inside the diverter value (adjusts suction from skimmer or cleaner)
3. Reseated and lubed the gaskets in the union leading into the pump
4. Tested the plumbing by using the diverter value; I get the same amount of air coming out of the return if I run all skimmer or all cleaner which suggests no leaks in either plumbing line
5. I also ensured the cleaner hose was not leaking by inspecting the hose as well as running the pump with the hose disconnected
6. Pool has auto water leveler so water level is good, I’m not sucking air into the skimmer
7. Checked all glued unions with soapy water – I also greased them up and applied kitchen cling wrap to try an make a seal – no change in the air bubbles

I have read that air leaks are usually on the suction side, however I have moved by efforts to the pressure side.

Pressure Side:
1. I have no water leaks anywhere
2. I replaced the filter gasket (it’s a Hawyard cartridge filter)
3. Also replaced the 2 gaskets at the top of the filter (where the top locks on and holds the pressure gauge)
4. Replaced the gaskets on both sides of the salt cell
5. Epoxy’d in the water temp reader that is drilled into my plumbing pipe between the pump and the filter (I wanted to make sure air wasn’t being sucking in here)
6. I believe the air is coming in before the water goes back underground (in the plumbing) because I see the air bubble floating around in the salt cell


With all this, any ideas? Specifically:

1. Any chance air is coming in through the pump without a water leak? I haven’t touched the pump other than to ensure the impeller is clear of debris. Could I have an issue with the impeller or pump seal?

2. What is the best way to check the pressure side unions for possible air leaks if I’m getting no water leaks? I tried the smoke trick but our days are just too windy. Shaving cream? Other?

3. Any other ideas? I also did not check or work with the union coming out of the pump other then to ensure it was tight.

Any and all ideas would be great. Thanks