Does the fuel return line that goes to the Charcoal Canister have any pressure or is it gravity drain? I have a 1986 off road only pickup that I mounted the gas tank in the bed. The fuel pump has 2 hose ends, 1, 3/8" and 1, 1/4" and 1 threaded tubing end that goes to the carb fuel supply. The tank has 1, 3/8" hose and 1, 5/16" hose and 1, 1/4" hose end. I connected the 3/8" hose from the tank to the fuel pump, and the 1/4" line to the tank fuel fill inlet, so it can send vapors in the inlet.
Can I run a 5/16" line from the carb return fitting to the tank and bypass the canister. Where should I connect the 1/4" hose end on the pump, and is this needed?
I will remove the canister and all of the hoses that are not needed.

 

there should be no liquid fuel going to the canister only vapors

 

"there should be no liquid fuel going to the canister only vapors"
This is a vapor line, I'd delete all that stuff if not in an emissions state, and can't.

 

OK, thanks, how does the fuel get returned to the fuel tank?

 

Are you using an electric, or mechanical fuel pump? Mechanical will have a return line marked as such, electric, you should have a pressure regulator on the supply side.

 

most Tanks
3/8" is fuel supply
5/16" is fuel return
1/4" is vapor canister
(most tanks will also have something like a 3/8" nipple welded or fitted to the tank for the filler neck vent)

most pumps
3/8" fuel supply from tank
1/4" fuel return to tank (norm if im not mistaking should be 5/16")
threaded is outlet to the carb

carb should only have an inlet and vacuum line (ive never seen a return on a carb but that doesnt mean ive seen everything)

 

Thanks Guys that answered all my questions, that helps a lot.

 

OK, one more question, the 1/4" or 5/16" outlet on the pump does not have a 1/4" or 5/16" hole in the end. It does have a button end with a small 1/16" hole in it. Is this this still a return??

 

can you depress the button almost like a check valve?

 

no all metal