Topic: Auxiliary fuel transfer tank

[HenryJ]

Sawzall in hand the first step to the tank install:



I had to cut the fill tube and add a few inches of height. I did not have enough filler hose at the shop, so I grabbed a piece when I returned home for dinner.

Crossmembers made:



Tank has been in and out more times than can be counted now.



Lots of drilling , painting and welding...



The tank is bolted in place. It hangs just below the frame rails. I now have two filler caps under the door-



All plumbed to the tank-



Pump line tee'd into the main tank fill vent line and the tank vent tied into the main tank vent line-



Another shot of the tank in place that gives a bit better perspective on how far up it hides. Well out of harm's way-



It is up far enough that I decided to go ahead and hang the spare back underneath. It is a bit lower than before, but not terrible.



A little lower than the hitch. It is above the bottom of the axle. 11" at the lowest point and 12" across the tire. While it may be too low for rougher trails, it is high enough for moderate trails and road duty. I can always drop it and toss it on top in the rough stuff , if I need to. As soon as the fuel gauge arrives I'll wire it all up and finish the project.

[oHIobellboy]

Now that's a first. I've never seen anyone do that before.  That spare tire bracket looks like the one that was on my 91 F150.

[HenryJ]

It is probably exactly the same spare tire bracket. The tank is listed as the same rear tank from 1990-1997.

My inspiration came from the install on my last truck where I installed a marine tank in the toolbox. Thunder II fuel tanks
The second tank was inspired by this install- Expeditions West Tacoma

The spare tank was one thing I really missed about my old truck. I'll soon have it online. The tank is listed at 18.1 gallons. That adds another 234 miles to my range. That puts me comfortably around the 600 miles mark. That seems to be the sweet spot for me.

[bluedevil]

Oh man that's too cool.   My uncle had a Furd custom van that had duals. Way cool. 


Like oob said, that's the first time i've heard of one doing this.  You rock dude.

[Flint 4X4]

I like it but as I have 34,000 on my '04 and only drove the '02 13,000 in three years,.. I question the need for extended range. It would be nice to have when I go to Canada an hour drive east, gas is expensive other side of the border. I drink coffee alot but passengers have to beg me to stop during extended road trips,
...my OEM bladder has a longer range than the OEM gas tank     

I've been known to hide in the woods camping, I could remain in seclusion and avoid civilization quite a while with 50 gallons of gas in the truck though and hope to retire soon, hmmmmmm 

[HenryJ]

I don't "need" the extra fuel all the time, but it sure is nice having the flexibility to choose when I want to fuel up. I never need to fuel on that busy price gouging holiday fuel. I can pass that out of the way , middle of no where gas pump to buy less expensive fuel.
I keep the main tank above 1/4 tank all the time. My hope is that helps prolong pump life. I fill probably once a month most of the time. That means less trips to town for gas.
It really has been a nice convenience and comfort. If I need to bug out, I am ready to go. If I need to bug in I have fifty gallons of fuel that can run the generator, or fill the motorcycles.

A trip over the border might be an issue if they question the second tank install. It looks pretty close to a factory job, but a suspicious border patrol might find issue with it? I am told that you can not transport portable fuel containers over the borders ,  full sometimes? Tax free fuel in this country is frowned upon. If the tank is built into the vehicle that does not apply.
That may just be Mexico where the diesels run across the border packing a 100+ gallon transfer tank and fill up on cheap Mexican diesel to bring over the border.

[Main One]

Nice Mod!  Thanks for sharing!!!

[bluedevil]

I think is great. Im going to promote this thread in the front page.

[Flint 4X4]

I don't "need" the extra fuel all the time, but it sure is nice having the flexibility,...

That's what I like about it, mods aren't always about need and I lean toward the functional/useful ones. I don't "need" an Avalanche but the thing is so versatile it sure is nice to have available when I do.     

[Richie_Rich]

Very cool.

This will have to go on my list of mods "to do some day".

[oHIobellboy]

Very cool.

This will have to go on my list of mods "to do some day".

You gonna be able to pull that off on a 2500? They've already got a second tank.

[Richie_Rich]

You gonna be able to pull that off on a 2500? They've already got a second tank.

I don't appear to have a second tank, unless it's some double type deal with only one filler pipe.
I thought it was just one big tank.

[oHIobellboy]

I don't appear to have a second tank, unless it's some double type deal with only one filler pipe.
I thought it was just one big tank.

There is an Aux tank above your spare that feeds down into the main tank as needed I believe. I know I've read post about that before. It does all fill with ony the one filler tube.

[HenryJ]

There is an Aux tank above your spare that feeds down into the main tank as needed I believe. I know I've read post about that before. It does all fill with only the one filler tube.

He is right. This was the first that I had heard of it but there is indeed a factory dual tank. I don't find an RPO code, so it must be standard equipment for the 2500?

It does look like the install might be somewhat "involved", but something I would have looked into further had I known. I wonder what size it is? It would probably be listed in the 2500 owners manual. A quick check in the Linked manuals here shows only 6.5 gallons capacity difference. Hmmm...
I think I'll be happier with an additional 18.1 gallons 

[Richie_Rich]

My tank is 37.5 gal.
I get just under 12 mpg normally and only about 8 towing.
Another 18 gal or so would be nice.

[HenryJ]

My tank is 37.5 gal.
I get just under 12 mpg normally and only about 8 towing.
Another 18 gal or so would be nice.

Looking through the repair manual, I would say that you already have dual tanks on the 2500. The 37 gallon capacity comes from the 31 gallon side tank and a small rear tank mounted above the spare tire and behind the axle. The two total just over 37 gallons.
It would likely be quite involved to add the 18 gallon tank to the 2500 as you would be removing the rear tank and need a single tank fill tube? The evaporative emissions canister may also have been relocated. That too might need to be moved?
It might be easier than I think. It will not be quite as easy and the install I am doing on the 1500 though.
I could be totally wrong though. The 2500 has everything in place and just needs a larger replacement tank. If you are willing to relocate the spare there may be lots of options.
I had considered one of the Streetrod Poly tanks
I think it is just a matter of finding what will work for a fill location and correct width. The 1500 has 36.5" between the rails and 27" length leaves room for crossmembers. The trick is finding a nice thin tank that works.

Rockauto.com lists the tank that I used fitting applications clear back to 1973. Tank Dimensions: 34 3/4" x 27" x 8 is shown to be a 19 gallon tank. It looks like I could use a different replacement tank that measures 34 3/4" x 27" x 13 3/4". The only difference appears to be the lower straps and bottom half of the tank. I do not see the tanks straps listed though. That is a 38 gallon tank. It looks like it would be a direct bolt in to the one that I have now. 5 3/4" lower would mean there would not be room for the spare under there anymore. Can you imagine? That would put the range out there at 900 miles. Nice to have that option available for a truly long ranger.

I picked up a LED indicator lamp and momentary push button switch today. The color coding for the factory pump and sender has been decoded. The gauge should arrive tomorrow and I'll complete the install.

[Alaska_AV]

hmmmm

I might be adding a 2inch body lift to my 2500.   maybe I'll give this a look if I take the body off

[HenryJ]

Parts finally arrived today.

The fuel gauge is in-



All wired up and ready for fuel. The gauge is a little lower than I might have preferred. The fuel button is in a nice place though. I may have to work a little to check the fuel level. Tomorrow I think that I'll heat the panel and tip it up a little bit.
I'll fill the tank and check the gauge calibration too.

[Main One]

 

[HenryJ]

I did heat up the knee bolster and push the top in more as well as adding a wedge around the bottom side to angle it upward a bit more.



The gallons display is now visible from my driving position.  Still need to fill up. I'll do that on my next trip to town.

[oHIobellboy]

Looking great Henry

[HenryJ]

As with any new project I work out the bugs as I find them. Filling the truck last night I found that the tee I inserted into the vent line for the transfer tank , served to restrict that and slow the filling for the main tank. Not acceptable.
I also found the during a transfer while traveling, the engine would stumble after a little while. I don't know what in the vent system might be contributing to this, but moving the fill line is a must now. That was the second strike.

I picked up a copper 1"x1/2"x1" tee and a brass barbx1/2" sweat fitting. This tee is cut into the fill tube for the main tank. I used some braided stainless line I had lying around this time. It held up well on the last truck too.




I put a splice in the vent line, so it is free and clear as it was stock. This should be a better solution and probably what I should have done to begin with.

The gauge is now set for 18 gallons when full. I think it is all where I want it now.

[Alaska_AV]

good work....


You make feel like a slacker

[HenryJ]

The cold slowed me down some. Highs around 20F and lows in the single digits tend to slow my enthusiasm for working on vehicles.

[HenryJ]

Finally made it to the low fuel light:


(cruddy cell phone pic)

564.9 miles when the light came on. I filled up at 569.6 miles. The main tank took 27.2 gallons to fill it. That leaves me about 4 gallons. That is a comfortable cushion. I can see 600 miles being possible. The auxiliary tank was indeed empty taking 18.2 gallons to fill. Total fill from the onset of the low fuel lamp illumination was just over 45 gallons.

Mileage on this tank was 12.5 mpg. Lots of winter driving conditions and warm up idling time. A good worst case mileage scenario.

[Flint 4X4]

Mileage on this tank was 12.5 mpg. Lots of winter driving conditions and warm up idling time. A good worst case mileage scenario.

I'd make that 10.5 mpg for worst case, that's still 500 miles. Translated to all highway I'd say 800 miles is possible with 45+ gallons.