If you pull the pump out again I bet you have a cracked circuit board on the float. Mine cracked when putting my FSVT pump back in and found it was cracked a few months ago when I pulled it out to see what was wrong. Don't know any solutions to it yet as I have not felt like pulling that b&s#a*d back out yet. It's cracked at around where the 1/4 mark is which would explain why the gauge doesn't come down until its about time to fill back up.