I hope someone can guide me. I have lived in this house for 15 years, and the well and pump have worked great until about 6 months ago. Now when the water runs for the shower, laundry etc, it pauses (no water) for a few seconds, and then starts up again. Any ideas?

Hello Pump Masters, Hooked up a new 3/4 hp Craftsman pump a few months ago to a shallow well and got it working good. Only use this well for outdoor use so the connections are simple; 2 ft of piping on the suction side, 3 ft on the pressure side. . . 30 gallon upright captive air tank. Lots of water, tons of pressure, no problems, BUT NOW --> The captive air tank is not filling with water, I can easily shake it, maybe 1 gallon inside. Pump pressure was 60, then 55, then 50 & now 40, it will pump water and reach prime and spray powerful but dies after a gallon, burst of air, pressure drops to 20, picks up prime, does the same thing. Air tank has 40 lbs of pressure and when I open the air valve only air comes out. This tank is only 3 years old. Have had a couple burst of rusty water but this has never clogged a pump or air tank in the past so I'm reluctant to open the pump and clean it since it's only been running 3 months, and I've had them running for years and never cleaned impellers or venturi's. Maybe a clog at the entrance of the air tank pipe? No water leaks on the pressure side, double checked for leaks on suction side, nothing obvious. . . ==== pump runs, won't shut off, max press. 40 lbs, captive air tank not filling no leaks ==== Just point me in the right direction and I'll fix it, :)