I have been learning about pumps and wells over the last 10 years out of sheer necessity. By myself, a couple of years ago I installed a shallow well pump. The old one was kaput.. I dont know all the technical stuff you guys mention, but I will try. The new pump seems to have only one problem, waterlogged tank, so I had someone install a spigot on it so I can drain it periodically. That fixes it, the pump had a gasket problem, I had someone fix it and he installed a pressure gage on the line. This has helped. Now we are at the present problem. I knew I had a small drip from one line, but it didnt seem to affect the pump operation...so I put off fixing it. Finally the drip got worse and I repaired it. So far so good. What tipped me off to the drip getting worse was that I noticed that the pump was running almost constantly.....a sure alert. Ok so I fixed the drip....all is good...run water, pump comes on, but....it wont ever shut off. The pressure stays around 40....I just have to run out and click the pressure switch by hand. Once I click it off...it stays off, till running water signals it to come on again. Whats happening here? Is there an adjustment somewhere I can make?
We have good well water, and it rained so I know the table is up.
My pump is a shallow well pump..Sears...paid approx 150 for it. My house/yard pressure is usually good.

You CAN teach an old dog new tricks !