I believe my pump is cavitating.
I have a clear strainer cover on my pump, so I can see what is going on in the strainer assembly.
When I remove the strainer cover it fills up with water, and will over flow. When I replace the cover there is only a small air space in the pump. Then after I run it for a few minutes the water level drops back down, and only fills the strainer assembly half way.
Also, my filter is only showing 4 psi, and it should read at least 5 psi per the new running reading last season.
I have replaced all of the o-rings and checked for a good seal, but air is still getting in there somehow.