Auxiliary Fuel Tank in place of a spare - how to do it?

[mankypro]

Can someone point me at information on installing the 30+ gallon 3rd tank in place of the spare? I want to plumb it as a thrid tank - how hard would it be to have it mechanically fill the other tanks after they reach a certain level? Or even make it gravity flow? Maybe have it on a toggle like the two I have in the truck now?

If anyone has a link to a howto I'd love to check it out.

p.s. I would like the solution to be completely analog IOW - no solid state stuff.

 

[Diesel JD]

You want to talk to Midnight Rider. He knows how to do that...its over my head. I think the gravity feed is pretty easy, but as far as I know he's the only guy to eliminate the electronic selector switch crap.

 

[ttman4]

If I under stand what you trying to do.....
One way to do a 3rd is plumb supply from it AND the original fuel supply thru a manual old style fuel selector switch....the kind you manually twist to set on whichever tank you want to pull from. Plumb the fuel supply that's now after the manual twist switch into fuel supply line AFTER the factory electronic selector switch.

Leave the existing return lines alone.
Now let's say you head out with all 3 tanks full, running on front tank. At 1/2 full on front tank fuel gauge you manually flip to new 3rd auxillary tank.....BUT LEAVE electronic factory switch set on front tank. Engine runs on new 3rd tank, but return refills front tank......or it would fill/overfill rear tank if you set electronic switch on rear tank.

Only problem with this setup is you have to watch fuel gauge to tell when to manually twist tank selector valve. Gets a bit sloppy, overfilled fuel tanks get your rig nasty & for some reason it PO's folks following 'ya down the road.
But it's one way.
Hope this helps a little.
Others on here got better setups.

 

[2manydsls]

I use a kitchen timer and it takes approx. 40 minutes of driving time to go from 1/8th to 7/8th on selected tank while driving.
Ross

 

[hahn_rossman]

If you add a third tank where the spare tire is, it will be lower than the other tanks. So gravity feeding isn't an option. Unless you need three seperate fuel sources I'd recomend getting a tank from a bronco of the same year and installing it where your rear tank and spare tire are currently. This allows you to use the stock filler neck and sender wiring vent etc. You either need to get a new sender/pickup or to modify the one from you old tank. You will also need the straps from the bronco. These parts are all readily available new, or from your local wrecker. As cheap as the aftermarket tanks are I would buy a new one. Good luck!