The Stovebolt Site Forums The Shop Area The HiPo Shop I NEED TO VENT..............

Or do I? I'm trying to determine if I need to run a vent line to my underbed tank. I went with the bed fill spout and the illustrations I've seen show the spout attached directly to the tank via a short hose, but there is no provision on the spout itself for the vent as it is on the stock unit. Is there another way to run a vent line or is it really necessary? There is also an additional outlet on the opposite side of the tank that I don't know what its used for. Someone suggested that it was there to relieve pressure buildup, but how do you go about doing that?

I just used a vented cap.

sometimes you just need to vent, it's ok. both underbed tanks i installed i hooked up a vent hose. i used a filler neck off of a older 50's chevy truck for one and another that i dug out of a junk box at a body shop. both had vent conection on the filler neck. that one you got is just too dang fancy!! i had a heck of a time finding the propper size filler neck to match the tank input connection so i just had to use what i could find. seems like it was 1 3/8" or something, smaller than filler neck off behind seat tank. i actually used a 1 3/8 freeze plug as a gas cap for a while.

The vent needs to be there to let air escape from the tank as you fill it. Otherwise the gas will back up into the fill tube and cause the pump nozzle to trip itself off. Use the nipple on the opposite side of the tank from the filler and attach a piece of heater hose, etc. to it and route it as high above the tank as you can. Stick a piece of steel wool or something similar into the end of the tube to prevent bugs or other debris from getting into the tank. If you've got stake pockets in the bed, that's a good place to put the vent tube. You can get it a foot or more above the top of the tank that way.
Jerry

you'll need something to allow the tank to breath during hot /cold expansion ranges and also while driving as gas gets used. just having a vented cap may not do the trick espacially while you are filling the tank.

try this
http://www.tanksinc.com/index.cfm/p...ory_id=62/home_id=62/mode=prod/prd97.htm

if you don't have a little extra thickness to the top of your tank weld a small strap or plug (bead blasted - electrical knock out) or ?? ,,,,, drill and tap it npt.

I have used a standard in-line fuel filter as a vent. more fool proof than a piece of steel wool. Running it up a bed stake would be fine.

You could also run the vent line back to the filler and drill/tap for a fitting, then run a vented cap.

OK, I think I figured it out. I found this vent tube off of a late model fuel spout. It has a a cap on the end that allows pressure to bleed off as needed. Is it ok for me to mount it on the spout as shown and run the other end to the opposite side of the tank?

Robert:
I would suggest you buy a vent with a built in check valve in case you ever flip your truck. That way you won't have fuel bleeding out and causing a fire.
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