Moparts

69 coronet gas tank vents question

Posted By: 7812845

69 coronet gas tank vents question - 01/30/15 03:18 AM

The gas tank for my 69 bee has 2 small vent tubes, one for venting that goes up into the trunk (which I have) and the other one is used for what, and what does that tube look like? I have a factory parts book binder, and it doesn't even list a part number for it.
Posted By: LYNCHROAD69.5

Re: 69 coronet gas tank vents question - 01/30/15 06:31 AM

See link below
http://a12mopar.com/yabb/YaBB.pl?num=1341832750/0
Posted By: LYNCHROAD69.5

Re: 69 coronet gas tank vents question - 01/30/15 06:34 AM

On page 2 of this link, better picture from FSM.
http://a12mopar.com/yabb/YaBB.pl?num=1238949100/15
Posted By: 7812845

Re: 69 coronet gas tank vents question - 01/31/15 03:20 AM

Thanks so much for the links and info. It sounds like the second short line is really not necessary and since I'm not doing a total resto, it sounds like I could just cap off the second, short tube. What do you think?
Posted By: LYNCHROAD69.5

Re: 69 coronet gas tank vents question - 01/31/15 04:19 PM

Quote:

Thanks so much for the links and info. It sounds like the second short line is really not necessary and since I'm not doing a total resto, it sounds like I could just cap off the second, short tube. What do you think?



When I restored my car, the short vent line and clip were in perfect condition so a put them back as I found them. I'm hard pressed to think there is not an important reason for the second vent, but i'm unaware of its specific purpose.

Being an engineer, my guess would be redundancy...remember your tank has to breathe. In order to breathe, your tank must have a vent somewhere that will relieve both vacuum and pressure. Gasoline expands in volume as it warms up and shrinks in volume as it cools down. The fuel level of your tank changes throughout the day, even if you are not driving it.

Up through the 1960's, most vehicles used vented gas caps. This is simply a gas cap with a hole in it. Unfortunately, this hole would allow the fuel to splash out when accelerating or turning a corner. Your car (69 B Body) I believe did not come with a vented cap.

Also, with one vent line, If fuel becomes trapped in the line your tank will build pressure or vacuum until there is enough pressure to purge the vent which will cause gas and/or odor to come from the vent line. If enough pressure builds up damage could be caused to your tank...thus two vents...to answer your question, would i cap it...no...but I think you will have to decide what makes sense for your application.
Posted By: 7812845

Re: 69 coronet gas tank vents question - 01/31/15 05:36 PM

I have checked several vendors and can't find one of the short vent tubes. If anyone has the specs on one, I might have to fabricate one.
Posted By: v10

Re: 69 coronet gas tank vents question - 02/01/15 08:29 PM

I think there is two vents, one for the front of the tank and the other for the rear of the tank. This is so the tank will vent if you are accelerating or braking.
Posted By: 7812845

Re: 69 coronet gas tank vents question - 02/01/15 09:47 PM

The gas tank I have which is new, has them side by side in the rear of the tank, which is what the FSM shows, with two vents. One goes up through the trunk, and the other one kinda looks like a 7. The one I can't find new is the one that looks like the 7.
Posted By: mikemee1331

Re: 69 coronet gas tank vents question - 02/01/15 10:00 PM

Quote:

The gas tank I have which is new, has them side by side in the rear of the tank, which is what the FSM shows, with two vents. One goes up through the trunk, and the other one kinda looks like a 7. The one I can't find new is the one that looks like the 7.


Dixie - http://www.dixierestorationparts.com/products.cfm?ci=DBB2D47E-CFBC-7B08-D0DC7D7E5E01451D
or Year One https://www.yearone.com/Product/1966-74-a-b-e-body/qrv2
Posted By: 7812845

Re: 69 coronet gas tank vents question - 02/01/15 10:04 PM

Posted By: VZCharger

Re: 69 coronet gas tank vents question - 02/01/15 10:09 PM

I distinctly rememeber that when I bought and installed my vent lines on my 69 Coronet it came with both lines. Lots of vendors list it as a 2 piece set.

Attached picture 8415564-IMG_20140301_141107.jpg
Posted By: 7812845

Re: 69 coronet gas tank vents question - 02/01/15 10:24 PM

I just need the short vent tube. The long one is still on the car. If I can't find just the short one, I'll probably just make one from brake line tubing.
Posted By: VZCharger

Re: 69 coronet gas tank vents question - 02/01/15 11:36 PM

http://www.manciniracing.com/futaveli2pc.html

When I touched my lines they came apart despite looking OK. They are only $25 for the pair at Mancini.
Posted By: mikemee1331

Re: 69 coronet gas tank vents question - 02/01/15 11:55 PM

Quote:

I just need the short vent tube. The long one is still on the car. If I can't find just the short one, I'll probably just make one from brake line tubing.



tsk,tsk.... it is a well known rule of thumb when working on old mopars that you HAVE to spend ridiculous amounts of money on the simplest things. it's a must and a given!
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