Fuel tank and line question

[Nowik35]

So I need help understanding what exactly I need to fully replace my fuel system from the fuel pump to the rear tank. Everything was so rusted when I was disassembling I ended up throwing everything away and now I don't know what I need to order to have a fully functional stock rear and auxiliary tank. Because I'm building a completely new body with all new pieces. What I'm confused about is I think I need a "filter neck pipe" for both tanks but for some reason I can't find any on TBP or JBGY. Am I missing something? I only see their tank kits but it doesn't include the filler necks? Why are these filler pipes so hard to find? Are they metal or rubber? Can I buy stock rubber fuel hose to substitute filler neck pipe? Anyways this is what I think I need.
Rear tank kit-TBP (I assume has everything I need)
Aux tank kit -TBP
Rear filler neck from LMCtruck
Aux filler neck from lmctruck
Two gas caps
12f nylon fuel hose (what size?)
Electric switch valve
Fuel hose hardware (clamps and clips to frame)

 

[DirtDonk]

Sorry you're having to deal with such extensive rust issues.
Can't help with all the details of the other companies' parts, but yes the actual "filler neck" is metal, while the "filler hose" (interface between the neck and the tank) is rubber.
Then there is the smaller "fill vent" hose which is something like 5/8" and is just to the rear of the filler on the main rear tank.

What year is your Bronco? They made two running changes to the filler neck designs in mid-'70 model year sometime, when there was a change to the evaporative emissions system with the charcoal canister.
The front aux tank did not have a fill-vent hose prior to that, but did when the charcoal canister system was added.
The second change was the design of the fuel cap and fitment. So an older fully vented cap could not be installed on a later filler neck and vice versa.

What year you have now is not as important I suppose, as how you want to set your Bronco up. Personally I prefer keeping the full venting system with charcoal canister to reduce fumes. Not just because it's good for the environment at large (which is a good thing surprisingly) but also to keep the local environment clear (like your garage, or the front of your house if it parks near a window, etc).
But ultimately since you're replacing the necks it's up to you.

Not sure why you can't find them on the other sites. They should be there.
This is what you'd be looking for: https://www.wildhorses4x4.com/category/s?keyword=filler+neck
Not sure if the older style is still available or not now that I look at that page and see we're listing them all the way back to '66.
The '66-'76 will fit all those years bodies, but you would have to use the newer style cap, add a vent to an older tank, and block off the fill-vent tubes if fitting to an early style aux tank.

Paul

 

[DirtDonk]

You'll have to look at your own fuel line size. Most are supposed to be 5/16" hose size, but I've seen am mix of 5/16 and 3/8 before.

You've listed nylon fuel hose, so check with the supplier to see what they recommend.
Not sure how nylon is fitted at the ends. Is yours supposed to just slip over or under rubber hose fittings? Or is it a modern specialty type tubing that requires specialized fittings?

Some companies make pre-bent metal lines for Broncos, and usually use 3/8 feed and 5/16 inch returns (if applicable) for the most common aftermarket tanks and carburetors.
If yours is all stock make sure they know that and can provide you what you need.

Paul

 

[Nowik35]

So yes I have a 69 all original parts. I rebuilt the original 170 with a stock mechanical fuel pump. That being said I don't know what size I should be getting. To show how amature I am in this process you just made me realise there's a return line in the fuel system. I wasn't even thinking that. Is there a nice diagram that maps out how the fuel system is suppose to be hooked up with both tanks a switch valve. Also I'm doing it all my self so I don't have anyone I'm working with in helping me figure out what to get.

 

[DirtDonk]

No return line on a '69. Just that the aftermarket tube setups have that option if you want to for reducing heat in the fuel, or need to for EFI.
Only in '72 and '73 (I think?) did Ford install return lines on those Broncos delivered to either high-altitude, or high heat regions.

Your fuel selector valve (when two tanks were optioned) will tell the tale. If it's got 3 ports it's non-return, but if it's got 6 ports it can be used as a return system.

Your six-cylinder engine probably uses 5/16" line all the way, but I'm only guessing and don't have that much experience with the sixes and if they were set up any different from V8's.
Ford and the other manufacturers tended to use as much similar fitments as they could no matter what engine, or option was ordered originally. So a single tank vehicle might still have had the second sending unit wiring in it's harness, and an inline-6 setup may have had the same size fuel lines as a V8.
But others will have to say. The good news is that you can easily get away with 5/16 the whole way as far as need is concerned. But you have to look at the fitting sizes to be sure.
Maybe run down to the local parts store and buy just a few inches of 3/8" and a few inches of 5/16" fuel line, and crawl under the truck with both in hand to see which one looks closest to a good fit on your fuel tank sending unit outlets, your selector valve fittings, and the lines at the fuel pump.

Does your Bronco use vacuum wipers? The '69 model year was the change from vacuum to electric, but I don't know if it was a running change, or if all '69's were electric.
Another thing would be the front turn signals and side-markers. The '69's got the larger turn signal lenses that year, but most still had the early style reflectors.
I know of at least two '69's that had electric side marker lights back in the mid-seventies. But since I did not know the original owners there was no way to determine if it was original or owner-installed.

Got sidetracked again! My point about the wipers was to determine what fuel pump you have. Even though you're going to check there in front of you, it might still be nice to see some pics of what you have while you're in there.
If you can take some under-hood shots of your carb and fuel pump setup, plus your tank selector valve and gas tank feed line sizes while you're checking them out, maybe we can help determine what you need better.
Of course, others may know for sure no matter what, and will hopefully see your thread and let us know for sure.

You can't upload pics directly to your discussion thread unless you're a contributor (12 bucks a year) but you can upload some to your "garage" (as I see you've done) or if there is a size limit and you want to upload some higher resolution shots you can send them to me at paulb@wildhorses4x4.com and I can upload them for you.

Good luck! Sorry I don't have all the answers regarding fuel line sizes, but someone here will.

Paul

 

[DirtDonk]

I see what looks like a non-vacuum fuel pump on your engine in the pics, but can't see the details. Can you take a close up of it?
And I forgot your rig was apart already(!) but you are sure you don't have any of the old fuel lines or tank fittings left? Threw them all out for sure?
Be nice to be able to check something out first-hand.

Paul

 

[Skytrooper15]

On my 70 model I have a 5/16ths OD nylon fuel line that almost goes to the fuel tank and then has a 8 inch piece of 5/16ths ID rubber fuel line that slips over the nylon line held by the usual squeeze type fuel line clamps and has the same going to the fuel line connection on the fuel pump but mine is a 302 so not sure if any difference.

 

[Nowik35]

Ya I still have the old fuel pump so I can measure tube input tube when I get home that should tell me what size fuel lines to use I would guess. No switch valve which now that I think about it it's weird to me bc I remember when I brought the rig home there was no aux fuel tank or a switch valve under the seat. Just a direct line from rear tank to fuel pump. BUT my damn still had the toggle switch on the dash and my left rear panel had 2 fuel gas caps. So I'm confused. Did they still use two gas caps even if the bronco never had the aux tank option?
Oh ya and the wipers are electric

 

[Nowik35]

Also this bronco will never see trails on my watch. Is it worth getting skid plates for the tanks?

 

[DirtDonk]

Ya I still have the old fuel pump so I can measure tube input tube when I get home that should tell me what size fuel lines to use I would guess.

Or you could just get a new one and see if it's the same. It's not unheard of for things like that to change from one manufacturer to another, or one decade to another as the old stuff is lost and the new stuff is made incorrectly-but-good-enough-to-work on an old vehicle like ours.
So maybe it's just best to wait until you get all the new parts you're going to use in the final assembly, then get the correct fuel line to match.

Really the pump, the carb and the sender might even have different sizes on them.
Would not surprise me if the carb had 1/4" fittings because it was originally used on an old car or truck from ten years before it was slated to go into the Broncos.
Sometimes you just have to punt. Not all answers are going to be consistent.

No switch valve which now that I think about it it's weird to me bc I remember when I brought the rig home there was no aux fuel tank or a switch valve under the seat. Just a direct line from rear tank to fuel pump. BUT my damn still had the toggle switch on the dash and my left rear panel had 2 fuel gas caps. So I'm confused.

Nothing to be confused about. This kind of stuff happens with 50 years and who knows how many PO's (previous owners) who needed to do one thing or another.
Does your driver's side floor look like it's been replaced? Sometimes the new floor covers the old hole for the valve and the installer just leaves it.
Sometimes the old tanks leak and someone just tosses the old one instead of replacing it, which would have cost money.
Or they were working on customizing it and got started, but never got around to installing the 23 gallon main tank in the back.
Lots of possible reasons.

Did they still use two gas caps even if the bronco never had the aux tank option?

Nope. Unless it was a mistake by Ford, the only year that you would have seen two tank openings and only one tank was the '77 model year with the gas doors. And even those were not 100% consistent.
My guess is yours came with two tanks originally but one was removed by a PO.

Paul