The unit I have installed has been in place for more than 5 years. Recently I have noticed that the pressure switch is cycling very often while water is running. Almost once cycle per 3-5 seconds of water run time. What is causing this? The switch cuts the pump on at about 38 psi and kicks it off at about 60 psi.

Check the air snifter valve on top of the tank. If water comes out you have a ruptured membrane and the tank must be replaced. Good luck. Tom

Yep. 5 years is not a lot of life from a tank, but it does sound like Speedball has it nailed down.