I have an IG pool with Cartridge Filter that is about 10 years old ( I've had it 2) .
It's been pretty reliable until this season. I keep getting air in the filter and pump basket.
I know suction side leak. I've tried shaving cream , Isolating the lines ( each skimmer and main), no luck.
Checked all Orings , they are lubed and sealed, many brand new. Hired a guy , he said I have no suction leak
since no air is viewable through the pre-pump view port ( sorry I don't know the proper name but it houses the
backflow preventer ). Several pool guys later they say there is no problem, but everywhere I read there should
be no air in the filter basket ( and there never used to be ). Pressure is 16. Filters clean, pool clean, chemistry spot on.
If I start it up , bleed air from filter, hour later pressure is 5 and pump basket is very low. No visible
water leaks. I've spent weeks trying to solve this so I can put the thing on auto, now it's got to be primed
every time I start. Odd thing occasionally all works perfectly and runs hours w/o attention, then the next time
it wont. Desperately seeking advice, I've been trying everything I can except replacing all equipment.