Hey guys and gals,

I have a 76 F250 with an in cab tank. I ran out of gas the other day when my gauge still said I had an 1/8 of a tank left. I figured I might as well check it out since I'm smelling gas after I fill up with more than 7 gallons. So, after draining the tank while it was in the truck I remove it to find that I still have 2 or so gallons still in it. The pick up tube looks like it is sitting on the bottom of the tank or maybe a 1/16 inch off the bottom. Anyone have any ideas why I'm not getting the last 2 gallons? Is this normal? Anyone else have a gauge that reads not empty at empty? The gas smell was a bad gasket on the sending unit.

 

Check the siphon tube for pin holes.

 

My guess is your gauge is off. Mine was when I first got it but the more I used it the closer it got lol, I swear it fixed itself.

 

How does the siphon tube come out? The fitting looks like it is brazed onto the tank. I was thinking the same thing but the inside of the tank looks very clean. I figured if the inside was even a little rusty then the tube could possibly have corroded, too. But then again, what else could it be if not a pin hole in the siphon tube. Is there a way to adjust the gauge like Bama suggested?

 

I looked at a drawing of the tank installation and it does look like the siphon tube isn't removeable. Don't really know how it could be checked for pinholes.
You can gently bend the float arm to adjust it.

 

I have similar issues with my 76 F250. The gauge seems to work, but the tank will be empty at 1/2. The needle will move after filling, so the float must be somewhat working. I'm going to pull the sender and see if I can fix it. I wonder if the arm is stuck. It's not quite the same problem, but when I pull my sender I'll see how my tube is positioned.

 

Thanks for checking it out in the parts book, Mike. I'll try tweaking the float arm a bit. And thanks in advance, Dr_Gonzo, for checking your siphon tube.