fuel tank vent line
 

hello all, I'm having problems with my 1970 plymouth duster I cant put fuel into the tank it always overflows out the fill nozel on-to my paint job? I bought a new sending unit and plan to tank the tank off and inspect do i need to intal a vent line or should I be looking for something plugging up my tank not letting the fuel in? Thanks yall have a great day FERGUSON

Do all the hoses and clamps and also a new filler tube to tank seal...
I Fill My Scamp with the front of the nozzle held to the bottom of the tube and also stop at the first click of the shut off.... Works for my anyway....
:)

Thanks Mr. Cowboy Bob after i get my new sending unit installed I will try that... Yes all tubes have clamps, but my filler tube is old and needs replaced my tank seal looks like it's in good shape. 6 more days of work then i will have some time off to tare into the tank and see exactly whats going on. thanks for your feed back Cowboy Bob

The vent really has nothing to do with filling. I've come to the conclusion that most of it is "at the pump." Here, I fill from about 3 stations in town, normally. There's a Chevron I pulled into one day that I normally don't use. Damn thing felt like it was under "high pressure." I told the cashier, and she said, "yeah we get some complaints." I'm like, "so why don't you FIX it?"

When filling, the air displaced by filling comes right back up the filler tube. The vent system would never pass that much air

Also, 70 was the "breaking" point for the evap control system. Do you have a big "can" in your trunk, that is, in addition to the filler neck? Originally, your tank should have hand only TWO fittings in / out.........that is, the filler neck, and the fuel supply line, unless you had a CA car with the EVAP stuff.

71 and later "they all" had the evap system.

These systems changed almost from year to year They are in the fuel section or the emissions sections of the service manuals.

You can download them in these links

http://www.forabodiesonly.com/mopar/...p?p=1970088617

http://www.mymopar.com/index.php?pid=109

Also from my mopar is a bunch of other useful stuff

http://www.mymopar.com/index.php?pid=31

Including the "Master Tech Service Conference" libraray

http://www.mymopar.com/index.php?pid=117

And on this page is "heated air intake and vapor saver"

http://www.mymopar.com/index.php?pid=427

Notice there is both a video and a pdf

http://www.mymopar.com/downloads/mtsc/271.pdf

and on this page for 71

http://www.mymopar.com/index.php?pid=428

"Evolution of the cleaner air system"

http://www.mymopar.com/downloads/mtsc/287.pdf

and this page for 73

"Cleaner air system Highlights

http://www.mymopar.com/downloads/mtsc/302.pdf

As I said, you may or may NOT have this system, as 70 was sort of a breaking point. Also there were several gas caps. 70 used at least two, with and without the evap stuff, and I think 71 was "all by itself"

Over at FABO, there was a guy "OldManMopar" who posted a photo of all the caps

http://www.forabodiesonly.com/mopar/...d.php?t=204919

http://www.forabodiesonly.com/mopar/...1&d=1347502256

No big can in the trunk lol and my duster has never been in CA, after i put my new sending unit it in and i inspect the tank and filler tube real well, I will try slowing the gas flow from the pump to tank down and try everyones great suggestions thanks all for your feed back have a great weekend!!!!

Check it !! The vent may be rusted ?

gas cap changes. had a 1999 dak. bought a locking cap. every thing fine. bought a 2001 dak. kept the cap. put it on the 01. a light came on. so it seams dodge changed the venting system. why am i NOT surprised? thanks Walter.

In that case the vent is very very simple

The gas cap should be "absolutely sealed"

Look at your filler neck up high inside the trunk. There should be a 1/4" line coming off the filler, goes up high and bends back down runs along the filler and goes through the floor seal. This tube then simply ends "open" inside the rear frame rail.

"That is" the tank vent.

As i said earlier, it has nothing to do with filling.

Download the appropriate service manual, above. That is what they are for!!! LOL