I need some help. I replaced my gould shallow well pump and tank. I primed the system and the pump runs and the tank pressurizes to 30 psi. As soon as I turn on the hose the pressure drops but the pump will not come on. I replaced the pressure switch but I have the same problem. I can walk away from the pump and after 20 minutes or so the pump comes on pressure to 30 psi and shuts off. There is not a leak because if I leave the pump alone the pressure stays at 30 psi. Why can't I keep a suction when I open the nozzle on my hose? Anyone have this problem or seen it before?