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Soldering vapor return onto a factory sender - how to avoid melting isolator?

You can remove the insulator and replace it after you solder the return port, with a modified bolt and seal it with some JB- Weld? I did this when I added a extra circuit for my low fuel warning light that I added.
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Mercy, there must be a dozen threads on here about return lines on our cars....
and yes, I've found the easiest way to search FBBO is actually to go to the google website and
search from there, as the search box on here is famously wonky as hell.
 
You can remove the insulator and replace it after you solder the return port, with a modified bolt and seal it with some JB- Weld? I did this when I added a extra circuit for my low fuel warning light that I added.View attachment 1162885

I thought about JB Weld, but it doesn't give me that much peace of mind on such a critical joint, particularly as I've found that - in my experience - it doesn't bite all that well on surfaces that vibrate (case in point, that Zamac 1:18 Road Runner in the back of my pics that I'm converting into a more-door model, using PC7 and JB Weld - have had quite a few joints fail in the process).

But if it's worked for you, all the power to you.

Wish there was a fuel-proof bulkhead fitting for this, or a plastic rivet-on replacement like the original available.

Mercy, there must be a dozen threads on here about return lines on our cars....
and yes, I've found the easiest way to search FBBO is actually to go to the google website and
search from there, as the search box on here is famously wonky as hell.

Well, I've been using my Google-Fu like a madman over the last few days. Since then, I've yet to find a thread that discusses, specifically, whether the return line for the Wix filter should be submerged or not, or any absolute clarity whether it returns fuel or vapor.

I also failed to find a thread that discussed soldering near an insulator, specifically on a sender. The one thread that had the most detail (an EFI conversion from 2009 on an AMX on the AMC forum) still didn't discuss the soldering techniques used. Given that this is my only OEM sender, and I have all of this long weekend to get it done, I had to be sure I didn't pfluck it up.

Maybe I missed these details somewhere, but I wouldn't have started this thread if I didn't think I needed help and clarification that I'd failed to find in the previous threads.

P.S.: I've found the Wix threads everywhere too, and while the return line is discussed, it's not often that the thread delves into how the return was connected at the tank.

P.P.S.: I did run into the far-too-difficult-to-find-on-Google-but-absolutely-essential-read thread at the a12mopar.com forum about the internal production issues with the reproduction 440 vapor separators though, and was glad to read through it.

-Kurt
 
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I think the Wix isn't metered, as opposed to the original 440 type which has the .060" metered orifice. Seems to work well for many though, including a fair number of forum members.



Well, I took the plunge and did it already, and - sure enough - the 150W iron was only hot enough to get the solder onto the surface, but following that up with a small butane torch did the trick. I wound up using a socket as a heat shield and heatsink, and it worked perfectly.

View attachment 1162875
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View attachment 1162879

Now, if it's not clear in the photos, I did wind up tilting the tube up, for better or worse. I was going off of some original 440 senders and it appears as if they were designed to dump above the fuel level, so I imitated that. Probably because they were metered.

I went ahead and started soldering before anyone had posted whether to point it down or up, so apologies to those who have suggested otherwise.

However, there's nothing stopping me from flaring the end for a fitting and connecting an inverted J-bend back down with an extension. Come to think of it, it may be the only way to do it and still get the sender to slide into the tank.



Makes sense. Seems to work pretty well for many on the forums though, and there's one or two videos on YouTube praising it. Doesn't necessarily mean it works for all situations, but I don't mind giving it a shot.

FYI, the vapor lock wasn't the primary issue - I'm installing an electric fuel pump at the moment - but I decided to add it into the mix as it'd be an opportune time to drop the tank.



Duly noted - see my reply to 70chall440 about my error in pointing it up.

-Kurt
Easy-peazy! Nice.
 
Congrats, good work. If you decide you want/need a bead in the end of that return line here's a tip, get some solid core wire (like for a house), cut off a piece and make a loop that fits over the line with the ends as close as possible, then solder that wire onto the tube and you have yourself a bead.
 
Apologies for the bump a year later for something that happened in April of '22, but I figured it's worth pointing out to prevent a fellow member from having to drop their tank twice:

If you're doing this to a factory sender - take a peek at your fuel gauge rheostat after you have completed your modifications.

I'm almost certain that jostling mine about resulted in the tab that reads the resistor breaking off. This was a bear to fix, as that pivot shaft is hardened steel and barely big enough to drill for a bolt.

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YMMV, but do yourself a favor and check the whole thing if you have one of these out. Save yourself double the frustration.

-Kurt
 
What I believe is these filters are just a way of returning a metered/restricted amount of fuel back to the tank. Not vapors. What it is doing is allowing cooler fuel to be circulated throughout the system and hopefully lessening vapor lock. Without the return fuel is deadheaded and prone to higher temperatures. Will all this fix the vapor lock? Jury is out.
Really?! The Wix filter will return to tank (through an in-built restriction) what ever is at the top of the filter, be it liquid fuel, or if fuel vapours are present (that will float above the liquid fuel), then vapours...

Hope it solved any issues you had cudak888.

It solved all my vapor lock issues. Tried electric pump with no return, still no good. Added this Wix filter and return line, all problems solved. I'm sure it would have worked a treat with stock mech pump, but I wanted electric pump for quick start with dry carbs.
 
Really?! The Wix filter will return to tank (through an in-built restriction) what ever is at the top of the filter, be it liquid fuel, or if fuel vapours are present (that will float above the liquid fuel), then vapours...

Hope it solved any issues you had cudak888.

It solved all my vapor lock issues. Tried electric pump with no return, still no good. Added this Wix filter and return line, all problems solved. I'm sure it would have worked a treat with stock mech pump, but I wanted electric pump for quick start with dry carbs.

Exactly. Though I'd expect it to be returning gases or boiling fuel more than anything - as I understand it, whole point of the non-returnless system is to circulate fuel when the existing fuel in the line starts to vaporize or boils due to under hood temperatures - thus ensuring a consistent liquid supply at all times.

So far it's much improved. Never any signs of vapor lock, e.g., a significant change from a smooth idle to a significantly rougher stumble, though the idle will change character slightly at times - that's when you know the system is circulating some boiling fuel and pumping cooler fuel to the bowls. Somewhat like the feeling when an EFI car changes idle slightly.

Never tried the electric pump with no return, nor did I try mechanical with a return - I wasn't about to try one or the other and I frequently run into the empty-carb scenario.

My only regret is installing a 3-second fuel pump ignition timer. It's fine if you're running a high-pressure EFI system, but I find that I have to turn the key about 3 or 4 times to fill the bowls when absolutely dry. Wish there was a 9 second version of the same, or a higher pressure Carter pump. Though, given the choice and if one hasn't already invested in the wrong system, I think it's still a LOT easier to do an in-tank Tanks Inc. conversion than an external pump. More options, less fiddly, and a lot quicker to install.

-Kurt
 
My only regret is installing a 3-second fuel pump ignition timer. It's fine if you're running a high-pressure EFI system, but I find that I have to turn the key about 3 or 4 times to fill the bowls when absolutely dry. Wish there was a 9 second version of the same, or a higher pressure Carter pump. Though, given the choice and if one hasn't already invested in the wrong system, I think it's still a LOT easier to do an in-tank Tanks Inc. conversion than an external pump. More options, less fiddly, and a lot quicker to install.

-Kurt
Hence why I built my own relay/timer system to run pump 15 sec on key on (I have 2 AFBs to fill) and to to turn pump off on oil pressure loss.

I never considered an in-tank pump, perhaps I should have. I thought it was more for EFI.

Just so glad vapor lock issue was sorted as my car was at times a hazard.
 
When I went from 5/16 line to 3/8 line I mig welded the line in place.
No leaks. Far enough away from the sending unit connector to not worry about too much heat.

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