Question about gas tank vents 4 vs. 1

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TAZLDAZL

TAZLDAZL

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When I was planning on replacing my trunk pan in my 1971 Demon, my plan was to go a head replace the 7 1/4 rearend with an 8 3/4 which is complete and my gas tank. I purchased one that has one vent tube, not knowing that there were two types to choose from. Last week when I pulled my old tank out it had 4 vents coming out and going to a steel tube about 1 1/2" diameter next to the gas fill tube. I also noticed that their is a vent line that follows the fuel line up the passengers side of the engine compartment. I have replaced the slant six with a 340. I have also bought the bigger 3/8" fuel line. Did the V8's come with one vent tube? And does the hose for the one vent tube go to the steel tube mentioned earlier or does it go somewhere else?
My question now is can I still use the one I have.
Thanks for any feed back on this
TAZZ
 
This is a good topic. My 72 Duster has one return line going into the top of the gas tank and it goes all the way up to the motor, Where I believe it is suppose to tie into the charcoal cannister. no lines going to the gas fill tube at all. This is originally a 340 car. My dilehma is my new 3/8 sending unit I bought also has another vent tube coming out that i won't need to use. it must be for the cars with mulitiple vent tubes, would be my guess. somebody with a little more knowledge on this will hopefully chime in.
 
Thanks Highwaystar for the reply,
Thanks for telling me about the vent line on yours going to the engine bay. I was about to go and rip it out. I think I'll leave it in for now. I may need it.

Any other replies would greatly help on this matter. I would like to just run the fuel line up to the motor and have the vent in the back to where ever. I have a set up like that in my Demon Braket racer. I just want to be sure.
Thanks again
TAZZ
 
I heard over the weekend that all 71 Dusters came with the 4 vacumn lines. My brother said his 71 340 duster had them, and that is how he told the difference between a 70 and a 71 model duster. ????? So maybe the 71 demon's were the same . I don't know for sure tho.
 
The four vent gas tank is a California emission model . You will have a separate tube in the trunk with five tubes at the bottom just behind the left rear wheel that match the tubes coming out of the gas tank.The fifth tubes runs to the front via 5/16 line to the engine compartment.From the end of the tube a rubber vent line is run to a nipple on the engine breather.The fuel filler is different on a four vent gas tank as well.Try looking up gas cap.It will ask is it California emission or not..If you run a single vent gas tank use the filler that was designed for the tank,likewise four vent gas tank,fuel filler and emission vent tube.If you start mixing parts you may run into a problem with tank not venting.I hope this helps you out.I if you want more info let me know.
 
Phantom70Duster said:
The four vent gas tank is a California emission model . You will have a separate tube in the trunk with five tubes at the bottom just behind the left rear wheel that match the tubes coming out of the gas tank.The fifth tubes runs to the front via 5/16 line to the engine compartment.From the end of the tube a rubber vent line is run to a nipple on the engine breather.The fuel filler is different on a four vent gas tank as well.Try looking up gas cap.It will ask is it California emission or not..If you run a single vent gas tank use the filler that was designed for the tank,likewise four vent gas tank,fuel filler and emission vent tube.If you start mixing parts you may run into a problem with tank not venting.I hope this helps you out.I if you want more info let me know.
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Are you sure about this? Every '71 I've seen has the tube in the trunk with the 4 hoses, and I'm in the southeast. I know my own '71 has that arrangement and it's never been anywhere close to California.
 
TylerW said:
Are you sure about this? Every '71 I've seen has the tube in the trunk with the 4 hoses, and I'm in the southeast. I know my own '71 has that arrangement and it's never been anywhere close to California.
Click to expand...

'71's have it, as well as '70 California models. I think that's what he was saying... '71's have it (50 state). Vented fuel filler/cap.

Do a search for EEC system. Evaporative Emissions Control system is what it's all called.
 
Thanks everybody for all the information on this. Now what I need to know is what are the differences betwwen the filler tubes? Can you tell by looking at them, because this is not a item that is for sale to often and they all look the same. If anybody has any pictures of the two post them or contact me and I can get them via email.
Thanks
TAZZ
 
The early 71 A bodys used a 4 vent tank 11D the late 71- 76 used a 1 vent tank 11E
I have them in stock for $140 The extra line on the 3/8 sender is used for a return line - Hemi & Six Pack
Thanks Vans
 
vans auto said:
The early 71 A bodys used a 4 vent tank 11D the late 71- 76 used a 1 vent tank 11E
I have them in stock for $140 The extra line on the 3/8 sender is used for a return line - Hemi & Six Pack
Thanks Vans
Click to expand...

So on my '76 Duster, the sender has two lines and then at the top of the tank there is another line. Correct me if Im wrong but it should be as below..

1. One line on the sender is fuel to carb???
2. Second line on the sender is return line from fuel filter??
3. Line on top of the tank going to little plastic unit under passengers floor and then continues on to engine bay is venting tube???

My Duster is was originally a 318 2bbl car and now it's a 383.. It was all running fine up until recently when the 383 went in and the car just doesnt want to take fuel from the filler...

Perhaps it could be something stupid like tank is full and gauge isnt working...????
 
You seem to be on top of it. The plastic device in the vent line is I THINK the overfill limiting valve, so you might want to see if it's causing your fueling problems at the pump.
 
TylerW said:
You seem to be on top of it. The plastic device in the vent line is I THINK the overfill limiting valve, so you might want to see if it's causing your fueling problems at the pump.
Click to expand...

I am sure it is. Some one took out all the vent lines and the tube in the trunk of my 70 Dart before I got it. It still vents because of the venting cap but filling up the tank sure does suck. I put my ear down near the filler and listen for the sound of gas filling the feed tube.
 
Can I use one of there 4 in tank lines as return line for gas to tank?
Two are smaller and 2 are bigger in diameter...
 
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