Yep - that was the first problem we had here after moving in. Well pump cycled constantly. First thing I did was drain the tank & check the pressure. Had 6 psi .... bumped it to 30, problem solved .... until a year later when the pump took a *censored* from all that cycling. Who knows how long it had been that way before we moved in. Had a leaky shraeder valve. Just grabbed another out of my pile, installed it, & never had another air related issue.
About a year after that pump failure I finally got around to doubling the size of the expansion tank. I also set the cut-in / cut-out pressures in a wider spread: 28- 66 psi. With no water being drawn, the pump runs for about 1 minute 40 seconds. Used to only take 40 seconds before. I went from 3 pump cycles per shower, to just one. That pump is now nearly 8.5 years old now. After the way that crooked well contractor installed the pump, I never expected to get more than 5 years out of it. He saw only my wife, so figured he'd pull a fast one on her by reducing my wide pressure spread to nothing, and releasing 15 psi out of the tank. When I got home from work, the pump would cycle 5 times for a glass of water!! At that rate, the pump would have failed in a month, best case ... and he would have swooped in for the rescue, charging mileage & $300/hour labor.
Guy didn't have the balls to return my phone calls. He knew what he did. Good thing I never saw that guy face to face. I would have fed him my fist!