94z28 Fuel leaking out of vent valve from tank?

This is a problem I have had since july 2008 when I first had the fuel pump changed out. Fuel leaks when the car is running and when it is off. It can leak up to 12 hours at a time. It get worse and better at random times, nothing specific. I have had it back to the shop where I got it done 6 or 7 times. I have burned up 3 fuel pumps in the process. 2 delphis and one carter. I have had the tank out myself, there are no kinked lines, or crossed lines. My evap system is in good shape. I have a good fuel pump relay. Also the pump is not running after the car is off. I have talked to so many people about I can't even count from performance shops to chevy dealers and no one can figure it out. Has anyone ever heard of this type of issue or have any ideas. Any help or ideas would be appreciated.

It sounds like pressure is pushing fuel out of the vent but the only way that could happen is if someone ran a hose down from the vent stub under the sending unit plate to the gasoline level like the hose thet vents the bucket or something crazy like that. It's just a guess but how else could gas get out of there if it's at the top of the tank where it's a half inch from the top? The vent tube form the top of the sending unit ony extends a half inch or so below the sender plate and the vent hose from the plastic bucket extends up towards the sending unit, but they don't get connected - am just wondering if someone connected that somehow. (edit: I later remembered there is a tab in front of the tank side of the vent tube that would prevent connecting a tube, so maybe that isn't a viable theory afterall...)

The only other ways out are through the charcoal cannister or a hole in the tank.

Do you have any pictures of what they did to it?

Also, I don't get why that is burning up your pumps unless something isn't being put together correctly or you are running out of gas or something.

there are 3 hoses coming from the pump itself the one with the quick disconnect is idiot proof so is the straight piece, so is the one that extends up with the 90 degree in it not supposed to connect anywhere, they have it connected to the little hose that comes from the vent line, the piece on the sending unit that is only about a quarter inch or less, if that isn't supposed to be conneceted thats what the idiots did wrong. I can't find any diagrams that show how the hoses should be connected.

Well that's exactly what I said. That hose just snaps in the little bracket and vents the plastic bucket to the top inside of the tank where there's air. It isn't supposed to be connected to anywhere.

Alright thanks for the help. Guess i'll be pulling the tank again, and going to get all my money back that was wasted.

Here's a picture of the damn thing

http://i219.photobucket.com/albums/cc158/kevinblownta/100_0754.jpg