1971 barracuda 318 fuel tank

[CUDA71383]

Hi all, my resto on my 71 barracuda, I bought it in 1984, wrapped it on a pole in the middle of winter when I was 22 years old then decided to restore it, now I'm getting it back together and have a question or 10.... ok the fuel tank I have it figured out except one major issue, on the top of the tank there is a hole 12 inches from the filler, I know the tank is vented from the cap and cant figure out y this hole is there, im thinking it was just covered by a piece of metal tape but doesn't compute, I have the 5 line
evap tube in the trunk..... does it need a fuel resistant plug or is it a vent to the right rail?

 

[moparleo]

First I want to welcome you to the site. Second, do you have pictures of your gas tank ? And finally, is this your car ?

 

[DetMatt1]

Welcome to the site from the Motor City!
We'd be happy to help but you'll need to explain this hole a little better at least. There would have been no holes covered with any kind of tape on a gas tank from the factory.

 

[CUDA71383]

tank pic

 

[DetMatt1]

No reason for a hole like that. I think you should take it to a pro and have it repaired.

 

[CUDA71383]

ahhh just got a manual from a friend in ont Canada there is a plug for it.....good luck too me to find it ..sorry not taking my original tank to a pro!!!!! im the pro!!! anyhow buying a 70 ta challenger tomorrow luv the e body

 

[moparleo]

Is it for a fuse ? A Canadian Cuda bomb?

 

[DetMatt1]

Just be careful what you do to a gas tank, that's all I'm saying.

 

[handbanana]

Hi, found this looking for fuel tank vent info. I just pulled the tank out of my 71 318 barracuda since it's been sitting a while.
The previous owner Por-15 'd the inside of the tank with a sealer - sealing 3 of the vent tubes! I have the vent tubes filled with MEK, hopefully this will break through.
The hole in top of your tank is supposed to be plugged, as you've mentioned. An aftermarket tank mfg may have this - my tank is definitely not original and has one.
Alternatively, maybe a piece of flat stock steel with a bead of Black Silicone to seal it.

 

[moparleo]

If the tank is out and is good enough to reuse with a boil out, why not just thread the hole and put a plug in it?

 

[DetMatt1]

I think it's just a hole in the tank so not enough thickness to thread. What was the hole for originally?

 

[71Plym]

My original 1971 gas tank had a plastic plug in the hole and a "Caution" label next to it. The hole is meant to be there and is a drain for the thermal expansion volume tank on the top of the gas tank.

The repop tanks have the same hole as the original US built tanks.

 

[71Plym]

"Caution" label next to plastic drain plug.

 

[DetMatt1]

You learn something new everyday!

 

[CUDA71383]

Tank

Ahh that is awesome thanks all! So with it being a thermal xpantion plug I have to wonder is it calibrated to relieve at a certain pressure. ....it shouldn't I'm Thinkin as stated it's a drain for the xpantion tank not a relief. I'm liking this site!!!! Now the restoration will resume!