No water in pressure tank. I have a swallow well pump 1/2hp changed pressure switch and turned pump on and won't get pressure past 30psi and pressure tank is empty. When I shut pump off it stays @ 30psi but, if you flush toilet or run water the water stops running. The pressure tank is light. If I open valve @ the tank it takes a matter of seconds till no water at all. Seems to be just draining from the lines.

Hi mlshimp and welcome, How much air did you put in your pressure tank?

Did you prime the pump? Removing the switch may have allowed air to enter the lines.

At 30 psi, does the pump cut off or keep running?