Since putting the FASS system on 2 days ago, I now have fuel coming out of the vent tube on the tank. What can be causing this? I know the pump puts overflow back into the tank and it is building pressure, but I don't think it should be puking fuel. I'm not talking about a little bit, I mean when I stop enough runs/drips off to leave a 1' diameter spot.
I'm thinking maybe the filler cap? Is there anyway to check the cap to see if it's good?
ANY help would be appreciated a bunch.

 

Is it leaking at the tank vent or the filler cap?? Did you remove the old fuel line? Could it be leaking where the fuel and return lines connect?
Clean it off and crawl under and see why it's leaking.

 

Leaking from the tank vent. Old fuel line is still in place. just hit me. The old fuel line is connected to the LP which is connected to the stock filter which is FULL OF FUEL. I bet when I got on it, the fuel in the line rushed to the rear. I bet the vacuum created by that is sucking the fuel from the filter assembly. I feel like such a Homer, DOH... I will verify today. Still trying to find time to remove the stock filter assembly and LP.

 

Yup......stock filter needs to be drained if you keep it in the truck. BUT even some residual fuel sometimes leaks out of the line....

 

I had drips from the old fuel line for weeks even after draining old fuel fiter housing...It stopped after a month or so...

 

Same here....