Hi All,
I was wondering if anyone might know what this might be...

I had my '70 Super Bee out on a fairly warm day last week. I added a few gallons of 91 premium to it (bringing to about 1/2 full) and drove around a bit. When I pulled back into my garage and shut off the motor, I could hear a very noticeable "gurgling" or maybe bubbling sound coming from the gas tank area. It was a sound similar to what you hear when your radiator is about to boil over.

Anyhow, after maybe a minute or less, I hear liquid running out on to the garage floor and sure enough there is a small puddle of fuel.

I crawled under the tank (by now it had stopped running out) and the only place I could tell where it MAY be coming from what this small outlet line (in the photo). Anyone know why this line is there? I suspect it's a vent line of some type, but should gas come out of it?

At this point, I could still hear the bubbling sound in the tank. I removed the gas cap and the sound went away completely. Put the cap back on and the sound came back.

This has never happened before in the years I've owned the car.... Any ideas? I'm especically curious if it's normal that gas can "boil over" and come out the vent tube like that??

Thanks a lot !

That vent line sould not be open like that. I would get a service manuel for your year model and put the vent system back stock.

Gas should never drip on the floor for sure.

Ok, thanks for the info on that.

Does anyone with a 1970 B-Body have a picture or know where this vent line should go to? I checked my factory service manual, but don't see a photo which matches mine. I imagine it's a rubber hose that connects here.. but to where?

Thanks a lot guys!!

My 68 road runner has a vent that's open just like that. It also has one that goes up into the trunk and comes across to the passenger side frame rail. Don't know what your gurgling sound could be. I could understand it stopping when you remove the gas cap but starting back when you put it back on?

I experienced the exact same thing just two weeks ago,except for the gas spilling onto the floor.
I crawled under the car and could hear it coming from the gas tank,and when I removed the gas cap it was quieted instantly.
I don't know why it did this????

Aren't the gas cap's vented? if so maybe the vent is not working and building pressure in the tank?

Thanks all for the help.

Here is my gas cap that I'm using.. It says it's "Fuel Emission Control - Pressure Vacuum" ...

It's the cap that was on the car when I bought it a few years ago ... Is it maybe the wrong cap for this setup?

The gurgling sound and fuel draining out only happened once (to my knowledge). Very weird...

Thanks guys!

My car (68superbee) does this also,i have a vent tube just like yours which just seems to hang in space,i don't know if this is correct or not.
if the tank is full or near full i get a small puddle of fuel on the floor.
when i open the tank cap the noise stops and i can hear some pressure escape.
this happens more on a hot day

Looks like the wrong cap. Thats an emission cap that doesnt vent into the atmosphere.Its letting the pressure build up. I dont have a picture of an early cap though sorry.

Thanks a lot guys. I'll get a vented cap for this car asap and try it out.

About hooking up the vent tube -- Does anyone have a pic of this on a B-Body or know where that vent tube needs to go to? I looked around in there but don't see anywhere to connect the hose to?

It looks like at least a few other b-body owners have a similar vent tube open. Strange..

Thanks a lot!

Vapor line normally hooks to the fitting on the tank, goes throught the grommet into the trunk, goes from the passenger side across to the drivers side then rises up about 5-6" then bends back down & exits the trunk through a grommet on the drivers side...



http://www.finelinesinc.com/catalog/product_info.php?cPath=277_513&products_id=1715

... ...I thought the non-vented cap is for the cars with the non-emmissions era vent {as in dumping on the ground/in the frame...The vented cap came along with the emmisions packages where the fumes were drawn into the engine by vacuum which in turn was the reason for the needed cap with a vent to allow air to enter the tank.. .So what I'm trying to say is your cap might be the correct one and it's simply the splashed fuel in the lines finding their way out....