Sand point sucking air?

I have a summer cabin on a lake with a sand point well. Last fall I noticed that it started taking longer and longer to get to pressure. The pressure switch was set 40-60. I eventually had to lower the switch to 20-40 to get the pump to shut off. The sandpoint is approx 20 feet deep and was driven about 20 years ago. The pump is a Craftsman Hydroglass shallow well jet pump installed in 2006. There is a 5 gal blatter type pressure tank on the system. I have replaced all pipes from the sandpoint pipe to the pump. This spring I can only get 30 lbs pressure and it takes a long time to bring up the water. How can I tell if the problem is with the pump or am I getting air somewhere?
Thanks,
hr

Lift problem or plugged screen!

I suspect a plugged sand point. It could be a lift problem however being a 20 foot well I doubt if that is the problem. I also doubt that it is getting air in the system because the pump would be loosing it's prime. You could install a vacuum gage in the suction line and if it reads 18 inches or more it is a plugged screen or lift problem. If the gauge needle shakes it could indicate air is getting into the system.

Pump problem

Porky, Thanks for the reply. I decided to reroute the pipe to a barrel and see if I could get pressure, before I replaced the sandpoint. Still no luck, so I took the pump apart and found a blown gasket on the body that holds the venturi and nozzle. I replaced the gasket and now I have great pressure and quick recovery.
Thanks.

Gaskets don't blow in jet pumps. Expecially inside of the pump itself. That hydroglas pump is noisy out of the box and plastic is a bad material for a jet pump. Usually when the pump gets hot like yours probably did, the plastic do dad that holds the nozzle and venturi warps disalligning the nozzle and venturi which makes for low pressure. If you got it back to working right again, you were lucky.

bob...