i scrounged up an old fuel tank that i think will fit nicely where the spare tire used to be. what degree of difficulty am i to encounter and has anyone some good advice to assist me?
do i need a fuel pump to help move the fuel or can i piggy back the spare to the existing tank..., maybe i should use a diverter valve...,
thanks for all your help!

 

Dave, gravety should bring the gas to the front of the truck. Most trucks that I have seen have some kind of valve to run only one tank at the time, although if you can deal with the guage issue, you shouldn't have to.
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John

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In the cool still quiet of night, you can hear chevies rusting away.

 

I'd put a valve in to switch between the two tanks. They are readily available at most auto parts stores. As far as the gauge goes, if it is a Ford tank and has the sending unit in it, you can run a SPDT (single pole-double throw) toggle switch to gauge the fuel in either tank. Just hook the wire that comes from the gauge to the center of the switch. Then hook the wire from each sending unit to one of the tabs on the ends of the switch (A SPDT switch has 3 lugs on it). That will let you switch the gauge between the 2 tanks. An auto parts store or Radio Shack would have the switch you need.

 

A couple of years ago I was told that you could not put an auxiliary tank on a 1970 short-wide, and that was why after market vendors (J.C Whitney, etc.) did not offer a tank for the short-wide F100.

Well, that was an immediate challenge.

So I went out and found a gas tank off a 1978 Mustang II (because it has a hump for the spare tire that allows it to be mounted high enough and provide a minimum of 12 extra gallons.

I took the tank to my local radiator shop to be cleaned. While they had it, I had them modify the filler tube so I could run it up behind the rear tire and out the side of the bed about 6-8 inches from the top of the bed (the filler hose is routed betwen the bed and the frame just as they do in other trucks).

I went to the hardware store and bought two of the tie-down straps used to anchor mobile homes.

Back home I welded a metal brace across the frame to support the tank, cut some rubber straps from old inner tube (to insulate the straps, fabricated some hangers (some welding, and hung the tank. It mounts in such a way that the hump rides up near the bottom of the bed.

The Mustang II tank uses a sending unit with the same parameters (resistance values) as the pickup, so it is compatible with your gauge.

Then I went to my favorite parts store (Honey, I'm home) and bought an electrically operated fuel tank selctor valve (switches the fuel line between the two tanks). I mounted a SPST (on-off) toggle switch to select tanks.

Since I had already fabricated an overhead console for all my gauges (I'm using a '67 instrument panel that has idiot lights for oil and altenator) except the fuel, all I did was install another gauge in place of the temp gauge (temp, oil pressure, and voltmeter now in console) and modify the wiring to feed the new gauge from the new tank sending unit.

I didn't see in your posting what year truck you have. If it is an earlier one with the mechanical fuel pump (driven by front of cam if a V-8), the pump won't know the difference between the main (original) or auxiliary (new) tank; it will just pump away, happy to have gas.

If you want to use one gauge with two tanks, you can install a DPST (double on-off) switch. Use one on/on section to select tanks and the other on/on section to switch sending units (be sure that you wire it so that if main tank is selected, main tank sending unit is selected also.

Sorry to be so late in answering your post. I've been putting a "new" cab/clip and engine/tranny/rear-end on my '70 F100.

I really like having 32 gallons of fuel on hand. It's especially nice considering I'm now running a 390/T-18/4.10 combination.

Good luck. Let me know how you make out.

Eddie Wilson

Keep smiling, it scares the he** of them.

 

Great Post Eddie, If you have or can get some pictures, why don't you put an Tech article together for that section of the site. Put it together and send it to Ken. He is always looking for new Tech articles. I would like to have it for my ClubFTE site if he doesn't.
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John

jowilker email me
[link:www.ford-trucks.com/users/jowilker|My Club FTE Page] Member since 01 01

[link:www.ford-trucks.net/users/jowilker/NCFTE.html|NCFTO] North Carolina Ford Truck Owners Group

In the cool still quiet of night, you can hear chevies rusting away.

 

I like what you did with that Mustang II tank. Where did the Mustang IIs have there fill caps out orginially? I want to put a gas tank where the spare goes on my 68 and run the fill hose out through the back where i can put the fill cap behind the license plate, then just flip the license plate down to fill her up, like in some of the old cars. Did the Mustang II work like that? If not do you see any reason why that tank couldn't be modified to work that way? Thanks for the valuable info.

-j.banks-



^^^^^^^^that's me stumped about something again

 

I currently have a tank off of a '72 Bronco that will
fit physically in my '72 F100. I just haven't got it
mounted yet.

Trail Rider

 

[updated:LAST EDITED ON 25-Dec-01 AT 02:41 AM (EST)]DING!!! The light bulb goes off. I never thought about a gas tank from a bronco of that era before. They obviously couldn't have had the tank behind the seat. Where did they have them mounted? Seems like the rails would be the same distance apart and all.

 

They mounted in the same place that you want to put yours. Right behind the rear end between the frame rails. The nice thing is they are narrow enough to fit the narrower frame on the '67-'72.

Trail Rider

 

Thanks for the info, you just made my day. Now if i can just find one.

-j.banks-

 

how about trying a international scout frames should be close to the same!

 

New early Bronco tanks are available from several Bronco parts places such as James Duff. Stock and larger ones are available.