When water pressure reaches the cut in pressure of about 35 psi (gauge on tank) the pump kicks on, and raises pressure to about 50 psi, it then hammers to a stop. After about 15 seconds, it turns back on and raises the pressure to about 57 psi, and hammers to a stop again. After another 15 seconds it turns back on, and runs until the pressure reaches 60 psi when the pressure switch cycles the pump off. I have drained the tank, and checked the pre charge, all is fine with that. There is no noticeable volume or pressure loss while taking a shower, or doing the dishes, so I don't suspect a low volume issue. The well is 10 years old, and has never given us any problem before.

Is your well pump attached to your pressure tank? I think it's key to find out if the hammering is from air in the lines or from vibration from another source. If I were in your position I'd look to see if the switch is making a good connection between the contacts (when it turns on - may be loose). If it was me, I'd try replacing the pressure switch with a new one (cheap $10-15 fix) and eliminate one of the variables.

In the back of my mind I'm thinking your well pump may be pumping air. But if you #'s are consistently 50-57-60 that's probably not it. If not I'm not sure how to go about fixing that problem. Good luck it's really a process of elimination.

Sounds like it might be pumping air. I would want to check water level in the well. How deep is the well and how far down is the pump? Are you in a dry spell in your area?

The well is 305ft and the pump is set 80 ft. The last two summers have been very dry, but this sring has been exceedingly rainy. There has been an earthquake, and several aftershocks about 150 miles from us, we felt some of the aftershocks, could the well have been caved in from that? Is there an automatic cut out in the pump if it runs dry? How do I test if this is the problem?

There is generally a "no water" cut off on pumps. If you know the pump is 80 feet down, you can try to check water depth by lowering a string with a weight tied on the end into the well. Have 80 feet marked off on the string, lower it that far, pull it up, and see how much of the end is wet. However, be aware that this can be unreliable since the well casing can be leaking water, can be wet itself, or from some other oddball source of water wetting the string. But it can be worth a try. There are other ways, but you will probably need a well specialist to go any farther.

To replace the switch is, indeed, an easy and cheap thing to try. I don't think you will get much out of that. It sounds as if the points on the switch are closing and staying closed until you reach 60#. The switch can't do much more than that. But, as Verhoff said, you can swap it out for 20 bucks or so if you are reasonably competent with electricity. It just doesn't sound like the switch is cutting off the pump until it is supposed to. Also, you can try filing the points (power off!) with an emory board, but again, that won't help unless the switch is the culprit, cutting the pump off/on repeatedly until you get to 60#.

If the water level has fallen to the level of your pump, the good news is that you can probably lower the pump farther down the well and get to more water. Again, a well specialist will have to answer that one. And that just assumes that water level is the problem.

Wish I could give you a better answer. Let us know how this works out.

Had a well company out yesterday, they checked everything I had already checked, and determined the problem is outside. They are coming on Monday with the truck to pull the pump, and see what the problem is, I will post the results.