I have a problem with my well. I have a subm. Pump 100 feet deep approx 10 feet off the bottom of well and 20 feet of water above the pump. I replaced the plastic pipe from the pump to the pitless adapter and I replaced both sides of the pitless adapter. The pump builds pressure turns off but has a leak and runs every 8 min. If you listen down the well casing you hear water dripping. Using a flashlight I can see most of the pitless and it appears not to be leaking (but I replaced it anyway) I hear it dipping so it is above the water line so I replaced the plastic pipe. It still is leaking the same, does anyone have an idea.

Check the pitless again the rubber o ring may be damaged. The best way to see the leak is with a mirror when the sun is out. Good luck keep us posted.

If your pump is cycling every eight minutes, then you have to be losing a gallon a minute or so of water. That's some leak! You might want to consider putting a checkvalve between the tank and the pitless adapter. At least that would prevent the pressure tank from emptying through the leak. Not a long term fix, I don't guess. Just a thought.

Are you saying you have replaced the wellpipe twice??