Dixie Life
Senior Member
It has to be me. This was the first time I topped off one of my fuel tanks. I wanted to get an accurate 20 gal. marks and total capacity for each tank. Here’s the setup, I shut off all valves to isolate the tank. Made sure the tank vent was clear. Started pumping an called out every 20 gallons to wife who would mark the sight tube. All good so far. When she said it was a few inches from the top of the tank I shut off the fuel at 280 gals. Now get ready. When I shut off pumping the fuel she said fuel in the sight glass dropped about 3”. WHAT? I pumped another 20 gallons. When I stopped, the same thing happened again. ??? I know there has to be a simple explanation but I can’t find it. What am I missing?