Well pressure tank won't hold 60 psi

[Sailor Dave]

Hi, I'm new to the site.

My well is doing the following:

If I turn off the breaker, then turn back on, the pump presses the pressure tank up to 60 psi. The switch then turns the pump off. Then the pressure in the tank starts to drop (no water running) to 40. A whistling sound seems to be coming from the tank. The switch turns on the pump, the pump gets the pressure up to 50 but goes no higher so the pump stays on.

I have:
replaced the switch and gauge
checked air pressure in tank (38 psi no water spitting out)
checked for leaks in well ( no water at connection where well pipe attaches to horizontal pipe running to house)
found no water leaks in house ( house is 11 years old)
good water pressure, no pulsing.
Also, a few days ago, the pump would press the tank up to 60 psi and the pressure would stay there until we used water. Now it won't stay at 60 so we shut it off when we aren't using water.

Any Ideas? Thanks

[Speedbump]

The fact that it gets to 60 then drops to 40 with a good aired up bladder tank suggests a leak somewhere. If it's down the well, it will not be noticeable.

Why it won't get past 50 psi now, suggests to me that you're leak has gotten bigger. Do you know what kind of pipe is in the well? Do you have a submersible pump or a jet pump?

[HayZee518]

pump

two questions, is there a foote valve at the bottom of the pump and is there a check valve going to the tank?

[mrcaptainbob]

Hissing sound...

Soapy water will be your friend here. Squirt some on the valve stem on top of the air tank. If you're hearing hissing, it may well be from that. If not, keep squirting the soapy water around any fittings. You'll see the bubbles. Do this after you pump up the tank to it's highest psi...
Do you know how to re-air the tank?