Sending Unit help!

[72bluNblu]

So I bought a new sending unit for my '72 challenger. Its the smog type tank with 4 vents on the side. My old sending unit had only one fuel line coming off of it with the pickup on the bottom of the tank. The new sending unit has two lines coming off of it, the standard one at the bottom of the tank and then another "straight through" line that goes through the sending unit plate and ends. What does this get hooked to? Obviously, if you fill the tank above the level of the sending unit this second line will have fuel, but once the fuel level drops below the sending unit it won't.

Any ideas? what do I do with this second line?

[MEK-Dangerfield]

It sounds like that second line would be a return line from the front of your car. Do you have a charcoal cannister in your engine bay? I really don't know much about this setup, as I don't have that, but I believe a line runs from the cannister back to the fuel tank.



   Mike

[72bluNblu]

You're probably right, but my car doesn't have the rest of the set up, the old sending unit didn't have the line. Probably suffering from a generic repro sending unit, they probably just make all of them with the provision for the return line that my car didn't have before...

[MEK-Dangerfield]

I'm just curious what sending unit you bought. My 5/16" didn't have the extra nozzle, but I have seen many 3/8" units with it. You can always just plug that extra nozzle you have on your's. 


  Mike

[RaptorF229]

I have the same sending unit. I just plugged it works fine.

[72bluNblu]

Yeah I bought the 3/8", bigger is better right  . I soldered it shut at both ends, seems to be working fine so far, I think I'll reserve judgement for a little while though...

[Scatterbrain]

Its the 3/8", I put one in my car and just plugged up the return hole.  I'm still working on that leak though...

[72bluNblu]

Soldering it is the way to go I think, I thought about a few different methods of plugging it but they'd all end up being temporary, and I didn't feel like dealing with it again. I just pulled the sending unit and let it air dry for a bit so the fuel would evaporate (its like 100 degrees here now) then soldered it up. Whole operation took about half an hour.