Stop in for a cup of coffee

How will that help? These things have a bladder. Once it gets water in it, it's done. I let the water pressure down to 0 to check pressure on the bladder. I will do that again in a few days and see if it still has 18 PSI. If not, I suspect it has a small leak. If so, I wouldn't want to over pressure it or I could split it open and then It would be 100% pump run...
The air is not in your bladder. It is in the tank. The bladder has the water and you can't build pressure in the bladder. It is like you squeezing the whoopee cushion. As the pump pushes the water into the bladder it builds air pressure in the tank. That is what pushes the water out into the house. Why do you think there is an air valve on top of the tank