Sending unit has weird vent thing

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Richie

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Hi everybody:

I didn't pay much attention to it because it was suppose to be the right one but the 3/8 sending unit for my 69 Dart has a weird vent tube going into the main line. Should I just plug it?

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Fuel vapor return line.

Do you have your old sender?

Is it functional, dies it look like your replacement?
 
It is a return line. It can be plugged as long as you have other vents for the tank.
 
It is a return line. It can be plugged as long as you have other vents for the tank.
There's the vent on the filler tube. The guy at the shop said "those things are ILLEGAL!!" I never heard of any A-Body blowing up from fumes in the trunk..
 
There's the vent on the filler tube. The guy at the shop said "those things are ILLEGAL!!" I never heard of any A-Body blowing up from fumes in the trunk..

They don't (and better not) end in the trunk. They end below the big rubber boot/ gasket in the rear frame rail.
 
Ok I have a PDF shop manual and I see what you mean by where the vent tube from the filler neck goes
 
Mopar never made a two nipple sender. These are aftermarket. If you have a later model (some 70, some 71, and all after) that has evap emissions controls, these cars vary. But all end up with a line from the tank vent system coming into the engine bay and connects to the "carbon can" evap system

You can just plug the sender fitting. If you ever build an anti-vapor lock system (they work!!!) you can use that fitting for a return.
 
Reason I was asking about your old one. If it is OEM. save yourself a ton of frustration and have it rebuilt. That way your guage will read correctly.
 
That's right, and they can make it 3/8 if it was 5 1/6. That new stuff is junk.
 
Call Tom at Instrument Specialties, he reconditioned my sending unit. He should be able to do it. A friend of mine swapped out the 5 1/6" to 3/8". Like post #15 said, unsolder the 5 1/6 tube, bend up a new 3/8 tube with tubing bender and solder or tig weld it back in. Get a new 3/8 end filter.
There are other people that recondition these sending units, maybe someone else can jump in with their names.
 
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Well I see his point now..I'm the idiot in this one because I thought it was perfectly fine to have the filler tube vent end in the trunk of the car. That's what he was commenting on.
gotcha, i took it as having the vent off the filler it's self he had an issue with
 
If you still have your OEM sender and don't plan to have it referbushed, I might be interested in buying it.
 
Mopar never made a two nipple sender. These are aftermarket. If you have a later model (some 70, some 71, and all after) that has evap emissions controls, these cars vary. But all end up with a line from the tank vent system coming into the engine bay and connects to the "carbon can" evap system

You can just plug the sender fitting. If you ever build an anti-vapor lock system (they work!!!) you can use that fitting for a return.

Actually 440hp and Hemi cars had a 2 nipple s/unit. 3/8" supply and 1/4" return. They had a vapor separator canister by the fuel pump where the 1/4" return lines starts and ends up at the 1/4" on the sending unit.
 
Found this pic in the shop manual. Looks like there is a small hole in the rubber trunk seal and the vent goes above the tank

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Was just going to detail this and realize, do you have the vent line?
 
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