Heavy gas smell

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Frnknsteen

Frnknsteen

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Hi Guys,

Quick question.... I am getting a real bad gas smell after filling the tank and driving. I even had one time where I filled up the tank and pulled around (to the left) to air up a tire and there was gas running down from somewhere on the right rear quarter. It is a 1967 Barracuda.

I assume I have something going on with the vent line for the gas tank. I looked under the car, but didn't see anything. I'm thinking I might be missing a portion of the vent line so gas can escape when it is full.

Can someone tell me where the vent line is supposed to be on a '67 Barracuda. I could pull the tank down and look, but just filled it. I will run it down so I can drop the tank easier to fix, but would like to know what I should be looking for.

Thanks!
 
I'm pretty sure the vent tube dumps into the frame horn so you can't see it underneath the car ( I forget exactly ). You could look in the trunk to see where it goes. 2 pieces are connected with a rubber hose just below the filler tube flange? My guess is you overfilled it.
 
So are you saying the vent comes up through the floor of the trunk? I've seen some models where there is a vent line that follows back up the filler tube to the filler nozzle. I didn't see that on mine though. I will look though. Car was filled until you could hear it start to gurgle, but didn't overflow.
 
Don't know then. Maybe fastback and notchback are different. On a notchback the vent tube follows the filler tube down through the floor gromett then turns and into a hole in the frame horn. Vapor or fuel bleeds out behind the wheel well.
 
This is on a notchback, so I will go out and look at it tonight and see if there is a vent tube that runs next to the filler tube. I know the previous owner said they replaced the fuel tank. I also saw online where tanks are listed as having 2 vent lines, so I don't know where those would be or if he one not connected to anything. I've run into other strange things the previous owner did on this car, so nothing would surprise me at this point.
 
If it's an old tank I'd check in this water holding area too............
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Frnknsteen said:
This is on a notchback, so I will go out and look at it tonight and see if there is a vent tube that runs next to the filler tube. I know the previous owner said they replaced the fuel tank. I also saw online where tanks are listed as having 2 vent lines, so I don't know where those would be or if he one not connected to anything. I've run into other strange things the previous owner did on this car, so nothing would surprise me at this point.
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Later models had multiple vent tubes, charcoal canisters, etc... I don't know what 68 w/ CAP might have had. Good luck with it.
 
Frnknsteen said:
Oh, ok. No,.. Trunk is in good shape with no rust, let alone any perforation.
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OK, to clear confusion. There is a spot on the tanks top where they hold water and rust through. Wouldn't be seen in the trunk. You said its a recent replacement tank so this probably isn't where your issue is.
 
RedFish said:
OK, to clear confusion. There is a spot on the tanks top where they hold water and rust through. Wouldn't be seen in the trunk. You said its a recent replacement tank so this probably isn't where your issue is.
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Ok,... I'm an idiot!! For some reason when looking at the picture Dave posted, I was picturing the spare tire well in the trunk!:rolleyes: I see what you're saying now.

I WAS told that the previous owner replaced the trunk. That being said,... even if he didn't. If that was my issue, I would think I would have an issue all the time since that spot is pretty low on the tank. The only time I have an issue is immediately after filling the tank, and especially when braking and turning, which is what led me to think about the venting.
 
So I finally got a chance to look at my car to see if there was a vent tube next to the filler tube on my car and there is. Vent line comes up the filler tube, goes around a loop and dumps back into the filler tube.

0321181603.jpg


I don't see how this allows the tank to vent, nor does it explain why I am losing gas somewhere when the tank is full. As I said before, I had one occasion when I filled the tank and pulled around to the left to air up a tire and gas ran out of the right rear side. It was actually dripping off the point of the quarter and wheel well opening at the back of the tire. There HAS to be another vent or something not connected properly somewhere for it to do that.

The tank is pretty full, so once I have a chance to run it down near empty, I will put the car on the lift and lower the tank on my transmission jack until I can see up and around it. Who knows,.... maybe where the vent line connects to the tank has a bad section of hose and the gas is getting out onto the flange of the tank and ran off when I rounded around to air up the tire. Seemed like a LOT of gas to do that though without running off anywhere else. It was a pretty good amount that ran out.

And like I said before,... the weird part is it only does it immediately after filling when the tank is completely full. No other signs of leaks or smell after that.
 
On your car the vent line should be going down under the car and ending there. Check for that when it's on the lift. If it doesn't end there and indeed does end in the filler tube you need to fix that.
 
kiss said:
On your car the vent line should be going down under the car and ending there. Check for that when it's on the lift. If it doesn't end there and indeed does end in the filler tube you need to fix that.
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I think I understand you. I guess I assumed the vent line came from the tank to the top of the filler tube to allow air trapped in the tank to escape as it fills (in other words, connected to the tank on the bottom and filler tube on top). It sounds like you are saying the that vent line is not connected at the tank, only at the top of the filler, so it can vent off gas and fumes below the trunk floor.

If that is the case, I suppose turning the car could get the fuel to slosh up the filler tube, and with nowhere to go, it would flow through the vent tube and dump below, causing the heavy smell and occasional spill that I have seen.

Makes sense. I will check it out. Thanks Kiss!!
 
Frnknsteen said:
If that is the case, I suppose turning the car could get the fuel to slosh up the filler tube, and with nowhere to go, it would flow through the vent tube and dump below, causing the heavy smell and occasional spill that I have seen.
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I wouldn't go that far. I'm not saying it can't happen, but i've never seen it. If you somehow, someway, had a very full tank, and 'sloshed' the gas all the way up the filler neck, it should just drain back down. The vent line is on top of the filler neck to avoid any gas that might somehow get up there from getting into the vent line.

Moving forward, you should definitely check to make sure that vent line is hooked up correctly (venting beneath the car) and clear of any debris.

From what you've described in this thread it sounds way worse than a vent line misshap though, such as when you described gas pouring out of the passenger side and down the fender. I'm sure you'll figure it out when it's on the lift and the tank is dropped. Good luck.
 
Frnknsteen said:
So I finally got a chance to look at my car to see if there was a vent tube next to the filler tube on my car and there is. Vent line comes up the filler tube, goes around a loop and dumps back into the filler tube.

View attachment 1715156013
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Ok, so your pic doesn't show all. The vent tube does loop right back down to the filler tube as shown but instead of re-entering the filler tube,,, there should be a strap welded onto the filler tube that holds the vent tube in place. This strap and the length of vent tube continuing down through the floor grommet was fairly well hidden on the forward side of the filler tube.
There have been issues with the aftermarket filler tube to tank seals but that fault spills fuel at the tank, not at the frame rail.
 
kiss said:
From what you've described in this thread it sounds way worse than a vent line misshap though, such as when you described gas pouring out of the passenger side and down the fender.
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"Pouring out" might have been an exaggeration, but it definitely wasn't a dribble. I would say maybe half a cup to a cup, which isn't a lot, but it's enough to make a mess and make me want to find out why it's doing it.

Like I said though, only for a little while. Last time we filled up and went for a drive. We had driven about 4-5 miles and rounded a sharp corner to head back towards home. Soon as we braked and rounded the corner (right turn) you could smell strong raw gas smell, then it went away and by the time we got back home (about 5 more miles) it wasn't doing it anymore. Not even when we hit the brakes a few times to check their adjustment.
 
RedFish said:
There have been issues with the aftermarket filler tube to tank seals but that fault spills fuel at the tank, not at the frame rail.
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I had exactly this problem just recently. Filled the tank to the brim, parked on a slope, and next thing you know my fuel tank was making a direct and prolonged attack on the environment.
It did just drip off the tank itself, not the frame, as you said.
 
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I had something similar. Tank was replaced with one that has a vent ( I’m guessing that’s what it was for) above the sending unit. It was capped with a piece of hose. Hose rotted, and when I filled the tank it would leak. Mine would leak right in the center though. As the tank and all lines are inside the frame rails I’m not sure how you had it dripping off the quarter panel
 
It sounds like the fill tube. You say the previous owner did some work back there. Did he restore the cargo area and perhaps drill through the fill tube while working on the cargo floor or door and not know? The tube curves under the cargo floor in the back corner where it hinges the cargo door in a fastback. Just a thought.
 
Frnknsteen said:
I know the previous owner said they replaced the fuel tank.
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If the previous owner replaced the tank, it's also possible they replaced the fuel sending unit lock ring. The reproductions are known to leak & not seal properly. Here's a pic--Top ring is a reproduction, bottom is original style...

It's worth a shot to check that too!

IMG_0287 (Medium).JPG
 
6pk2goDemon said:
If the previous owner replaced the tank, it's also possible they replaced the fuel sending unit lock ring. The reproductions are known to leak & not seal properly. Here's a pic--Top ring is a reproduction, bottom is original style...

It's worth a shot to check that too!
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Thanks 6Pak. I had heard that too, and saved the one out of the tank on my Charger in case I needed it, but hadn't thought about that on this issue. Thanks for the reminder. I will take a look at that too while I am under there to see if there is any sign of that leaking there :thumbsup:
 
Fill tube? You said that the leak was on the right side. The only things on the right side to leak are the fuel line and sender "O" ring. The vent you are showing is correct on the left side. The other source on the left side would be the rubber grommet where the filler tube inters the tank.
 
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