Fuel tank leak

[Ounty]

After filling the fuel tank on the way to SDC meeting the tank started leaking. Could the vent line, if it extended to bottom of tank, act as a siphon? 

[mfg]

It's possible that the fuel tank sprung a leak....Avanti fuel tanks have been known to leak at the spot weld locations (these welds secure the inner fuel tank slosh baffles)

However, I'd first take a close look at the two rubber hoses that vent gasoline fumes from the tank....These two 1/4" hoses are notorious for cracking and allowing fuel odors to escape......with a full tank, the liquid fuel itself can leak out.

Also, check the condition of the large rubber hose connecting the tank to the outside filler neck....That hose can also split open allowing fuel and/or fumes to escape.

[JLBKY]

You asked about the "vent line" extending to the bottom of the tank and acting as a siphon. I'm rather certain that it does not extend into the tank as you described. In my opinion, the only  certain way to determine the source of the leak in the gas tank, is to pull the back seat and the rear panel behind the rear seat, so as to get a good look at the tank

Before I'd pull the back seat etc., I'd look at the fitting on the bottom of the tank that connects the tank to the fuel line. Is it leaking there? Inspect the fuel line around the left rear axle that is/was covered with a rubber tube. The gas line is known to rust there.

Once you pull the rear seat and panel, check the sending unit and the return fuel line fitting, as well as the hoses described in the above post. Good time to replace  ALL of these rubber fuel  lines/hoses.  Make sure you use a good quality hose that can handle today's crap gas.

IF you have to pull the tank, you MUST remove the fitting on the bottom of the tank to get it out.

John

[Ounty]

Thanks for my marching orders. I'll keep you all posted.