Shut off the well pump and drain the water in the pressure tank by opening a water valve immediately after the tank.
Put a tire gauge on the air valve available on the pressure tank to determine the pressure in the air bladder. The air bladder, filled with air, pushes against the water to provide the needed force to deliver water through the water piping system to the home. Find the air valve on top of the tank or somewhere near its bottom.
Make note of the pressure. If it is more than 2 degrees below the cut-in pressure of the well pump, this is a good indication that the air bladder lacks the needed air for help in pressurizing the water delivery system. Add needed air to the system but stop at the cut-in pressure point of the well pump, such as 30 pounds per square inch.
Check the air valve for leaks. After filling up the air valve, listen for hissing or released air coming from the tank. Replace the air valve if it is leaking.
Shake the empty tank gently. If you hear water sloshing inside, this means that the air bladder is ripped or leaking causing the waterlogged situation. The only solution is to replace the pressure tank because the air bladder is inaccessible inside the welded and sealed tank.