Cannot fill gas at a pump

[Flipper_1938]

Originally Posted by John Henke

My wife has a 2007 Yaris. A few days ago I was going to fill it with gas to discover I needed and eye dropper to put in the gas because the filler neck kept filling up with gas and shutting off the pump. Well today I fixed it. Here’s the problem, what causes it and how to correct it.
The think vent on top of the gas tank has a rollover valve. If the car ends up on its top this valve has a weight that will shove a piston into the vent closing it off. These vents are designed to stay closed even after the car is righted. When the valve is closed the air in the tank can’t vent to the carbon canister when the gas is being pumped in.
The way I think it gets closed without being inverted is because a Yaris is such a bump-mobile being as light as it is I think inertia drives this weight into the valve when hitting bumps in the road. Maybe a little at a time the vent just gets closed off, or a really big bump will do it maybe. This car has over 60,000 miles.
Here’s the fix. Detach the vent hose at the carbon canister; it’s the one toward the front of the car. Take off the gas cap. Use an air compressor to pump air pressure into the vent line; you’ll have to make up some kind of stopper to make the connection fairly air tight. Apply 15 or 20 PSI to the line for about 30 seconds. Pull out the connection and it should expel some of the air and gas fumes. (No smoking during this procedure.) You should be able to blow air into the tank and suck it out just with a hose in you mouth. In fact the hose in the mouth is a good way to confirm that the vent is closed.
This is what I did today after thinking over the situation for a couple days and reading the posts here and looking at the schematics. I went to the gas station and locked the handle on full and it just filled right up. Good luck, don’t buy parts, you can do this yourself.
John Henke.

You probably blew the guts out of the ROV with that sort of air pressure/volume. Time for a new gas tank.