well was drilled in 1972 changed pump 2x.everthing OK till just the other day switch started 2 kick in & off ever few seconds.just put on new switch ,still doing same thing.well tank has 30lps pressure.water flow still good.can someone help?

Sounds like your tank is waterlogged. Is there an air valve on top of the tank? If so, does water come out when you push it? If so, then bad news.

You can also try "pinging" up the side of the tank with a screwdriver handle or hammer(tap lightly). When the tone changes, you've hit air. Should be about halfway up or so. If the tank is full of water (no air), then you've found your problem. You can refill the tank with air as a temporary fix through the air valve. Turn off the pump, open a faucet to empty the tank, and use the air valve to put a low charge of air in. Turn the pump back on to complete the process, but be aware that the air will slowly dissolve into the water over a period of several weeks until you are back to where you are now.

Has the tank ever been replaced?

Thank you jlisenbe.no have never changed tank.I did suspect the tank being waterloogedthe air pressure but will try with the tap test.

well was drilled in 1972 changed pump 2x.everthing ok till just the other day switch started 2 kick in & off ever few seconds.just put on new switch ,still doing same thing.well tank has 30lps pressure.water flow still good.can someone help?
If your bladder tank were water logged the pump would kick on every time you made a draw. But you didn't say that in your question. The way you put it was that the pump kicks on and off by itself. If that's the case it sounds like a faulty check/foot valve that allows the pressure to be bled off forcingthe pump to build up pressure and quit only to have the pressure bleed off starting the pump all over again. My vote's on the check/foot valve. Regards, Tom

I agree. But I would think the owner would want to eliminate the simple and easy to fix before going to something more difficult. I wouldn't change a foot valve before at least checking the tank first.

I agree. But I would think the owner would want to eliminate the simple and easy to fix before going to something more difficult. I wouldn't change a foot valve before at least checking the tank first.
The way he voiced his complaint didn't indicate a bad bladder tank. It pointed to a faulty checfk valve. If it were a bad bladder tank his complaint would be that the pump kicked on every time he drew a glass of water. It wasn't. He complained that the pump would, "the other day switch started 2 kick in & off every few seconds". This tells us that the pump would pump up to pressure then lose it and start pumping again. Ya don't lose pressure if the membrane's ruptured in the bladder tank. This is a check/foot valve problem.
But you raise a good point. Unless the complaint points to a definite item , as this one did, it's best to check the easy stuff first. Regards, Tom