I have a double (twin) pipe deep well jet pump. I woke up one day and the pump would run for a long time then shut off for 5 seconds and start up again. I shut the power off to the pump and the pressure in the pump and my holding tank both dropped quickly to 0 and I heard all of the water in my pipes gush back into my well pipes. I pulled my well lines out of the well and saw the foot valve was cracked and replaced it. When I primed the jet pump and restarted it, the psi doesn't go higher than 25 and the holding tank won't fill at all. However, all of the pipes throughout the house are filled with water and the pump seems to be pumping water fine. Would not having a venturi on the jet assembly cause this? I really need help with this because not only do I not have water, I rent out an apartment on the second floor of my house and they have been out of water now as well. Thanks for any suggestions.