This is my first post on this site so I hope I provide the info you need to answer my question. I really appreciate all the unbiased help available here.
This is the first year we have had this problem. We have a 6000 gallon above ground, vinyl pool, a 1hp Sta-Rite Cristal Flo pump, and a single polypropylene solar panel installed (for the second year) between the filter and the return. The pressure gauge shows 17-20psi and returns to 0 when the pump is off. Since opening the pool this year there has been air in the top of the filter basket pot, air bubbles coming from the return, and gurgling sounds in the solar collector system. The vacuum is the type that is simply inserted in the supply hole in the bottom of the skimmer. When I try to vacuum, the hose remains floating and the pump gradually takes in more air then loses prime. There is enough pressure from the return that I can barely hold my hand against it (I admit I'm no Charles Atlas). So much for the symptoms.
I have checked the following for wear, debris, and leaks:
1. the large o ring around the top of the basket pot
2. the o ring at the drain plug
3. the threaded connector where the supply line attaches to the pump; I re-wrapped it in Teflon tape
4. the connector and o ring at the wall of the pool
5. visually inspected the 6' flexible supply hose for clogs or cracks; it is only 1 year old
6. saw no signs of leakage under the pump which might indicate a worn mechanical seal in the pump
7. I could not insert my fingers from the basket pot to feel for a clog in the impeller because there seemed to be a cone-shaped "shield" inside the hole.
It would seem my next step is to open up the pump to visually inspect the impeller, but before I tackle that I wanted to clarify whether or not the solar collector system might be the problem. The installation instructions say, "Always fill the system from the bottom" which I took to mean "hook up the supply hose first." I think this is what I did, but it was a very hot, brain-dead day and I'm not sure. Could this be the cause of my problem or is there something else I need to check?