Shallow jet pump, low pressure, drained tank 28 psi, holds pressure at 40 psi continuously runs doesn't shut off, nor fills the tank, black filler line runs from under switch into regulator, clear both while pump off, briefly turned on to flush before put back, primed the line. Turned on same results. Someone mentioned the regulator, I try to read as much as I can , with knowing nothing, I was about to change switch, when the mention of this regulator. Any guidance would be greatly appreciated.