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Odd sending/pickup unit

abn373

Contributor
Full Member
Joined
Jan 6, 2012
Messages
377
Loc.
Charleston, SC
I am posting this because it may help someone do what I sort of thought about for a second and maybe it's interesting, or maybe not at all.
I am changing to EFI and while gutting all the fuel lines and pumps and such, I figured I would replace fuel pickup/sending unit that was in the truck when I bought it in 1997. It has a vent line in it. I thought for a minute about using that as the return line which would be clean, but when I went to order a replacement, this doesn't seem to be a Bronco unit. (My truck is an early 73) So when I couldn't find a replacement, and I was worried that the vent line would be too small anyway for a EFI return line, I decided not to bother with it. But if you look at the attached pics, the angle of the pick up and the float and everything is identical to the new Bronco one. Maybe a Mustang or something? Doesn't seem like they would have the same tank. BTW, I have had that extra vent or emmisions line capped off since I bought it, and vent out the side tubes of the original tank.

It seems like if you could find this sending unit and attach a hose inside (or not? I hear about aeration) you maybe could use it as a clean set up for a return line. I looked for a part number on it in case anyone wanted to try it, but it doesn't appear to have one. Regardless, it was still working after 30+ years. The new one I put in will probably fail in a year :confused:
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DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
46,674
That’s not a vent. It’s a return line tube fitting.
Found primarily on 73 only, but with a little crossover, I believe too late 72, it was found on the high altitude and hot region Broncos to avoid problems associated with or related to vapor lock.
They have never been reproduced in the aftermarket that I know of, but several people have made their own. It’s a great way to do a return line actually.
Do you have the matching manifold up near your carburetor? It’s found in the hard line from the fuel pump to the carburetor and it’s just a simple brass block I believe where the return line splits often goes back to the tank.
A lot of things have been changed on Broncos over the years, and most of them got tossed out during a carburetor swap, and other things.
 
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abn373

abn373

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Full Member
Joined
Jan 6, 2012
Messages
377
Loc.
Charleston, SC
Well damn, it must be the original then. I think I may go back to my original plan of using it for a return line and put it back in with a new o-ring. I guess if it ever fails I could scavenge parts from a new one to rebuild it. It will save a pain in the ass step of adding a return line.

As far as the parts up front, they definitely aren't there now, but I can't remember if I took them off decades ago or if previous owners did.

Thanks for the information fellas. As always a wealth of knowledge here
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,551
And if you still have the original fuel tank selector valve under the seat, it will be a 6-port. As it has to handle the return valving as well as the supply. Part of that fuel return system.

I know other manufacturers also used the same system. Sometimes the return was built into the fuel pump (3 fuel lines on the pump) and sometimes it was built into the fuel filter (3 fuel lines on the filter).
 

thegreatjustino

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Red Head Grease Monkey
Joined
Jan 23, 2002
Messages
15,503
Loc.
Stockton, CA
I have a bone stock '73 that I bought from the second owner. The full return line fuel system is intact, but the Bronco wasn't ordered with the side tank, so no switching valve (six port or otherwise) under the driver seat. The fuel system is an oddity for sure.
 
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