Last year I pulled the gas tank and inspected it for pin holes, etc. It was all good, painted it and replaced all the hoses to the vapor canister. Also replaced the 5/16" sending unit and put a 3/8" unit in. Replaced the fuel line with 3/8", holley mech fuel pump with pressure regulator. Car ran fine but I noticed that sometimes it leaks from the vapor canister on top of the tank. Ran it today and after a few minutes the drip started, getting worse over time. Opened the gas cap and the drip slowed and stopped. Appears the tank is building pressure which is pushing fuel out the vent tubes into the vapor canister. Hard to believe since the tank is only 1/4 full.

What could be the cause?

A friend had a similar problem and he just by-passed the whole emmissions vapor canister system by capping off the vent tubes. Kinda concerned that this will result in the tank building a lot of pressure. Any comments on this?

Thanks,

The vapor separator probably has some pin holes in it if fuel is coming out of it. The whole side was rusted out of mine and I had the same problem.

You can try to solder or braze up the holes in the canister or just bypass it. I ended up just plugging 2 of the vents and leaving the other 2 open with pieces of fuel line going up to the shock crossmember area. I would replace the separator if I could find a new one.