Evap vent valve leaking gas when filling van at gas station

Have has issue after issue with this van. A couple of months ago I found the evap vent valve was dripping gas. So I replaced it thinking that it was bad. Yesterday I was filling with gas at gas station. Ran inside to grab a red bull…came back and noticed liquid on the ground. Got down on the ground and noticed that it was coming from the vent valve. This is a new vent valve. So…that makes me think that maybe it isnt the vent valve that is the problem…Is the canister clogged? To where it was over flowing out of the vent? This van is killing me.

I learned on here that newer vehicles, as in the last 20 years, have a valve in the tank that closes to prevent fuel from flowing through the EVAP system when the tank reaches the top. Maybe that valve is stuck open. Older vehicles don’t do vapor recovery when fueling.

Since they made the GMC Safari for 20 years (1885-2005 IIRC) it would help to know a little more about the vehicle… a few things changed in 20 years…

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There should never be a time that the EVAP vent valve is exposed to liquid fuel. There is something else wrong with your fuel vapor containment system. Do you ever top-off the tank after the nozzle automatically shuts off?

The canister may be plum-full of liquid gasoline, possibly b/c dirver is overfilling the tank, or, more likely the purge valve isn’t working correctly so the gasoline fumes stored in the canister never moves into the engine to be burned… A caller on a recent Best of Car Talk podcast had a similar problem. In that case Ray believed the carburetor was flooding b/c of a faulty float valve, and raw gasoline was moving from the top of carb into the charcoal canister via the vent line. The humorous part of this story: The caller referred to the canister as her car’s “charcoal pot” about 10 times … lol . .

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I stopped asking that question after getting “schooled” on how that can never happen by certain people on here, even after I have seen it happen myself many times… lol

lol … I presume you are referring to the change in the evap system design which occurred at some point on most modern cars, done to mitigate the problem caused by owner’s overfilling the gas tank and damaging the canister and producing a big repair expense, making the owner’s mad at both the manufacturer and the dealership. May be a little annoying, but that’s still worthwhile information , esp for diy’ers.

My Corolla’s factory service manual seems to have a couple of errors in its description of the car’s evap system theory of operation. It says when the pressure in the gas tank gets too high (like from the car sitting in the sun) the spring controlled vent in the gas cap opens, and this forces the fumes into the canister. Seems more likely the gas cap vent valve never opens in normal operation, & is a safety device to prevent gas tank over-pressure in the event the canister vent path fails. It also says there’s only one path for air flow involving the canister, from the outside towards the engine during purge. But there’s another air path, from the canister to the outside during re-fueling.