Is my F-350 2011 Ford diesel supplsed to have pressure on the fuel tank when I remove the cap?

Is my F-350 2011 Ford diesel supplsed to have pressure on the fuel tank when I remove the cap? - 1

No, you should ck, the vent to make sure its open.

It's probably vacuum, not pressure, and the answer is yes, a little is normal. The lower the fuel level, the greater it becomes.

If the truck takes fuel, there's nothing wrong with your truck. Opening the cap will normally produce a slight whoosh sound.