I recently attempted to upgrade my sand point well system, the old system was 12 years old and the pressure was low, but it held pressure. I put down a new sand point 3 feet away from original point, aproximate distance 15ft deep This is in a basement. I used 1 1/4 galvanized pipe with driving couplings connecting. Also new check valve and union inline close to pump. The new pump and tank and pressure switch are all in one,the tank is 5 or 10 gallon. I installed a gauge and the switch is a 30/50 switch. It took me 4 attempts to prime unit and get water. Once I had it primed the unit worked perfectly and I was really happy, I let faucets run to get clear water and any air out of system. This system is in a house I currently don't live in so the water is not ran daily. I went back to check on system and it has lost its prime, this is the second time. I even pulled the point used teflon tape and pipe dope, I really put the pressure on to get get tight fittings.I have 6 feet of water in point and pipe. There is a 1inch clear hose from pump head to "T" in tank, factor installing pipe clamps, I have tighten. Any suggestions on how to fix, I am going to buy additional pipe clamps for hose. Could new check valve be allowing system to loose pressure? Any suggests/ help would be greatly appreciated.

Thanks
Jay