Air entering well line

[Amopower]

Hi all,
I recently replaced my well pump (used for irrigation only), with an exact replacement. (Flint & Walling 3/4hp, jet pump). I just bought this house and apparently the previous owner had not run the irrigation for at least ten years. Since the pump looked like it was at the end of its life, and because i wasn't getting enough water, I replaced it.
I also replaced the two lines coming in and out of the pump with clear PVC so i could see what is going on. Glad I did, because what I see is air coming in the line entering the pump, which in turn is affecting its ability to keep up with the demand. (pump basically drops immediately from 55 psi to 35 psi when i turn on an irrigation zone, and the pump runs continuously until the zone is turned off. The sprinkler heads pop up strongly at first but then slowly die down to a low level)
My thoughts are that there is either a crack in the piping somewhere along the line, or that it's sucking in some air at the foot valve because the water table is dropped low enough to be around the foot valve. Is there anything i can do to prove either of these? I wasn't sure how to locate the well head. I see where the pipes come out under the house and then under the sidewalk, but that's about it.
I would say the system is about 25 years old.
thanks
Scott

 

[Valveman]

You will need to dig up the lines and find the well. You either need to fix the leak in the pipe, lower the footvalve if possible, or rehab the well if it is not making enough water.

 

[Sponsor]

 

[Amopower]

I bought a soil probe and actually found the well, without tearing up my yard, that was pretty cool. I took a picture of the fitting that converts the two 1 1/4 inch pipes down into a 2 inch I think well pipe. As you can see the fitting is very corroded so I don't even know what this is called or what I should look for in terms of a replacement. However, I filled this hole up with water and ran the pump and I still got air in the line so I don't think the air is coming from the fitting.

I took a video so you can see how it behaves, notice that it seems like large chunks of air are entering, yet the output side doesn't have that much going out...can't figure that one out either.

 

[Reach4]

I think it would be called a 2 inch casing adapter for concentric 2-pipe jet pump systems.

What you probably should do to replace it is to extend your casing and use as special pitless adapter for concentric piping.
http://www.affordablewells.com/2-cross-section.html


At the bottom there are seals called "leathers". I am not at all familiar with such systems even from the standpoint of having read material.

If you think that your casing is more than 2-1/2 OD, then my sketchy ideas above are wrong.