In the past I have simply removed the bushing that the gauge is screwed into and manually poured water into the pump to reprime it, today however, no matter how much water I pour into it, it will not fill the pump, yet there is no visible sign of water running out under my house...
Sound like you need to install a check valve. That way the pump will always been primed. Also how far from the suction side of the pump is the water that is to be pumped.
Check all gaskets, seals and ‘O’ rings. If all of the seals are rubber or synthetic rubber, use a petroleum jelly over them before tightening the fittings. This should remove any chance of air getting into the system.
In the well is a foot valve which is basically a check valve with a screen on the inlet to the valve. It is not holding the water in the pipes going down to the foot valve, so all the water you are putting into the pump is just going into the well. Pull the pipe or pipes out and replace the foot valve. Check all connections while you have it pulled and check for bad spots in the pipes. Put back together and reprime. Should be good to go! Hope this helps! Good luck!