Hi: I have a shallow well pump in my Maine camp that just started giving me problems. The system is made up with a 26 gallon pressure tank, 3/4 hp jet pump and a smart pressure valve. What happens is sometimes but not always the pump continues to run after some water useage, toilet,sink etc. I go down to the pump and see maybe 10 lbs of pressure on the gauges, if I manually shut the pump down and wait a minute to turn it back on it will sometimes come back up to pressure , fill the tank and shut itself off. This doesn't always happen, some times I have to remove the priming plug and put in a small amount of water, this seems to do the trick. I have spent a good deal of time checking everything, I took apart the so-called smart valve and cleaned it up, I removed the pex pipe from the well casing (11/4 pipe) and cleaned the foot valve, the casing is down 25' terminated with a perferated well point, I have water at 18'. This is an intermittent problem that seems tobe getting more frequent. Any suggestion would be welcome, also whats the general consensus of opinion on these smart pressure vales. Thanks.