Bubbles in the pool

[Themoleman]

I have been given so many confusing answers at different forums but and my mystery is still just that. There are a small amount of bubbles in the pool and cavitation in the pump filter basket. You can also hear air in the sand a dollar. It all works okay…for usually a week or so then I come out one morning and the pump is not priming. I finally found a good article at a blog that shed some light on it. Bubbles in the pool are always air leaking in on the suction side so it goes. I had a leak detection company out for a leak problem, it turns out, in my tanning bed. While they were here they also performed a pressure test on the skimmer lines. Both lines held pressure, a lot of pressure. So I bought a new filter basket lid, clamp down ring and gasket. All worked well though still air bubbles. A week later, in the morning , no prime. The last place I will check is the connection at the front of the basket. When they pressure test the air bladder they use goes in far enough that it would be after that connection. But I can not easily get it to unscrew. Any tips on getting it apart? I would hate to break it. Getting parts is hard at the moment I’m told due to supply shortages from China, and I would need to replumb the line.
As well, do pumps age to the point they can not pull enough water? I can only get one skimmer line to draw. The bad one I just have off at the diverter. The pool leak guys determined it is not blocked and suggested the pump can not handle both lines.?

[Denniswiseman]

Air in the returns is a suction side air leak and the fact that the lines have been pressure tested is great and it's all above ground
Did you lubricate the new "O" ring with silicone grease?
Shaving foam round all suspect places (unions or joints) will suck in
I doubt that the pump is at the point of no return, what is the pressure like on the return
It's possible for the pump impellor to be blocked

[Teapot1]

Tricky one as there are many variables. If the pump has to draw up from both skimmer lines and doesnt i would look at the pump impeller, the little slots can get clogged by debris and are often neglected. You can usually get to the impellor via the pump exit port if some twit hasnt made that all glued connections. Getting unions to come undone is often tricky but a good strap wrench can often do it with a bit of silicon sprayed into the thread if possible. Some strap wrenches have kevlar in the straps, these are best wheras the Boa are pretty useless.

[Themoleman]

Update August. Thank you for all of your ideas. Unfortunately things you think are set in stone sometimes are not. Since my earlier posts the collar for the union on top of the pump broke so I decided to just at this point re-plumb everything. All pvc joints,unions etc. afterwards the pump basket was still full of bubbles and I could still hear bubbles in the Sand Dollar. Now keep in mind the multiport has a new top that I installed but the base is the original due to my pool store ripping me off and ordering me the wrong multiport when they replaced the sand dollar. They got a 2” but remember, they did not tell me and put the old one back in and put the new ring one in my basement. Well today after all the new plumbing I backwashed and it seemed a tiny bit better during backwash. Then for unknown reason I put it on recirculate. BAM! No bubbles..zero. Next put it on rinse…no bubbles. I put it on filter…no bubbles. So it is neither a suction side or any side issue. It’s the mutiport or something in the sand dollar. But recirculate did the trick. Now we will see if it primes tomorrow on it’s own. Thanks again

[Teapot1]

Multiports can still drag in air, often from the waste port as it can act like a venturi with just a small hole letting by the spider gasket inside. Its tricky on the other end of a PC.