Fuel leak at sending unit

[cudasteve72]

My tank seems to be leaking at the sending unit.  I pulled it out re seated it with the rubber gasket, and it seemed tight and sealed.  took her out and when I got back the tank seemed wet.  it wasn't pouring out like it had been the time before but there is a lot less gas in it.  The set up I'm using has two ports on the sending unit, I have one going to the line and the other capped. (is this a mistake).  I feel like the sending unit would be the weak link as far as pressure goes and that may be the tank needs to be vented some how.  The locking gas cap seems to be holding the preasure but I'm just not sure.  What do the Experts think?

Thanks

[dodj]

I'm no expert, but if you are using a new sending unit and lock ring, use two rubber gaskets. The new lock rings are thinner than originals. 

[dfrazz]

Double check your hose connections too.  And make sure you don't have a hole in the tank or fuel nozzle.

[DadsCuda]

could any of you guide me as to how/what to cap that second port? is there something made especially for that or is there a certain grade/type of rubber i can find at the auto parts store?
here i thought running the fuel lines would be the easy part!

[jimynick]

While mine also has a new sender, there was a member who advertised thicker, oem style rings and I bought one and used it. Mine also has a 1/4" vent tube coming out of the sender as well as the 4 other vents and I was figuring on going all sophisticated and using a chunk of 1/4 neoprene, FI type clamps and a nice, shiny 1/4" bolt in the end of it to plug it. I'd also be interested in offered variations. 

[tman]

Think you just need to take a look down below once you get the engine going and accumulate some vacuum/pressure in the tank.  Take a short drive and inspect while its running.  The second port on the sender, smaller than the primary outlet, is for a return line.  Return line is for fuel line hose.  My second port is not capped, a return line is on there.  Good way to hook up that return line is add a Vapor Separator (helps with vapor lock in hot weather).  As some has said, the new lock rings are thin.  Did you replace that? or use the old stock one?  If you used a new one, it is looser than the stock lock ring when you turn it.  It will be ok statically, but once you get pressure in the tank, fuel can come out the rubber gasket area. 

This seller on Ebay sells what they claim are NOS lock rings.  Anyone get one of these?  I made the stupid mistake of throwing my old one away when I replaced the sending unit, but fortunately I have no leaks.

http://www.ebay.com/itm/19571978-NOS-MoPar-Sending-Unit-LOCK-RING-300-Fury-Charger-GTX-Cuda-Dart-Duster-/142015687206

[4 speed fish]

I used a rubber cap with a small hose clamp that is used for fuel.Do not use a rubber cap that is for vacuum.The gas will eat it up over time.

[DadsCuda]

 I don't suppose anyone has a picture of their vapor line or vent line? I'm a very visual person when it comes to setting things up. I have a small vent line attached to my filler pipe, but not sure that's the line that should extend to the extra port on the sending unit??? (My Haynes manual is no help here)
While we're at it...my old j bolt rusted off my car & ive had some welding don't to the frame...any chance there's a shot of how the tank strap is attached (bolt end) on a 67 cuda or similar?