Gas Filler Trouble

[TR65]

I don't know if anybody else has the problem that they can't easily get gas into their under bed gas tank. Here is my solution in any case.

Years ago I put the gas tank under the bed for my LS conversion.

I didn't want to put the filler in the bed floor since the truck hauls all kinds of stuff. I mounted a fuel cell snout in the inner bed side and ran a 1-1-2" steel tube down to a 2" straight rubber line into the tank. I ran a 3/8" vent line up between the right bed side and the fender.

I could never get it to fill properly. I had to manually nurse the nozzle and could never use the automatic fill, too fast. I always got gas spray out the filler when full. A lot of pumps now are so fast I can't use them at all. (You might notice in the picture the right angle joint in the steel tube. I replaced that with a gentle radius bend, small help.

I tried a number of crazy solutions, two of which ended up pressurizing the gas tank and blowing gas all over the bed.

Turns out it was a venting problem. Gas pumps deliver gas at at rate of about 4 - 9 gallons per minute (the max is supposed to be 8 but I have timed some at 9). The 3/8" vent line could not evacuate air fast enough. Moreover it is not at the very highest point in the tank so there is no vent when the tank is about full.

It seems vehicle manufacturers use either and external vent line into the filler near the cap or use a tube within a tube design where gas goes in a small inner tube and air is vented through a larger outer tube. My solution is in the next post.