I have an '03, ext cab, short bed, and the 26 gal. stock tank. It is 12 miles to I75 and the cheap truck stop fuel. Usually 8-15 cents cheaper and I'm sure fresher than here in town. But with only a 26 gal. tank, it's not worth driving over there just to buy fuel. Fuel at mile post 201 on I75 is usually about the lowest price on Eastern half of USA, BTW.


My normal driving is just around town with an occasiosnal trip of 100 or so miles. I've only got 16k since I bought in Jan. 2003. But then a few times a year I hook up my TT and head out for a trip, last fall travelled 3000 miles in 3 weeks. Couple of times on that trip I had to buy at places I normally wouldn't as I try to buy from large volumn fuel stops, like Loves or Flying J, but I was afraid I was about to run out of fuel!


I have a shop equipped with aluminum welding machines (both tig and spool gun mig) and have been considering building a tank similar to one I saw at Tractor Supply that costs $630! It is an inbed tank, sort of "L" shaped and fits in front of and underneath a cross bed toolbox. These tanks hold around 80-90 gals. IIRC.


This is my first diesel and my concern is whether this amount of fuel would be OK as far as not going stale, becoming water contaminated, etc. Also, would it be OK to plumb it into the return line with gravity to be used only when engine is off? Any other suggestions on plumbing?

My in-bed aux tank is plumbed into the system with a 6-way valve that swaps supply, return and gauge sensor. I alternate tanks continuously to keep the fuel "fresh" in both tanks. The valves are available stand-alone from JC Whitney and others. You could check with American Tank www.auxtank.com (http://www.auxtank.com) to see if they would sell you a valve and wiring harness seperately. Having two tanks makes it a whole lot easier to deal with fluctuating fuel prices and being able to "shop around" when on the road interstate (nice to wait until you get out of a high-priced state and fuel up in a more reasonable neighboring state!)

I had an L shaped tank built that fits behind and wraps under my Retrax canister, sandwiched between a bed mounted toolbox (which sits just in front on my 5th wheel hitch) and the front bed wall. Built from steel, with I had Line-X'd. I gravity feed, via a ball valve, into to stock filler hose. I have discovered, by accident, that leaving the valve open, even with the extra tank full, will not cause the stock tank to run over. I don't drive with the valve open.


I have had this set-up for 15 months, and it has worked for me. I only fill the extra tank when I am going on a long trip, or am pulling my 5th wheel. Other than that, I run off the stock tank. I do put 10 gallons or so in the extra tank monthly when I am not using the tank, just to keep things semi-fresh.

HoustonDMax, how did you tie into the stock filler hose? I understood that it is a double hose with the inner being fill hose and outer the vent. Is this correct? Please elaborate.

I gravity feed through the outer hose only (rubber), not through the inner plastic hose. I simply installed a 3/4" pipe barb, using electrical conduit nut (concave matched the rubber hose curve) inside the rubber; don't remember if I put anything on the outside. Sealed it with silicone as I was installing; no leaks. Slid rubber fuel line on the barb sticking out of the fill line. Fills through the vent with no problem.


I can get pictures, but it will be next week. Packing up this evening to head out for the labor day weekend tomorrow morning.


Let me know if you want pictures.

Yes Houston DMax, We (I) want pix if it would not be too much trouble!!


PDS

HoustonDMax post here if you can, I want to see. You was smarter than I. I had a person install a custom tank fitted below my tool box, but it was installed so that the truck ran directly off the aux tank. Never again will I setup that way, it will be a transfer tank, gravity feed, just like what you have described. Just wish you had done yours first, so by example I would have done the same.

Now don't shoot the messenger, but I believe that gravity fed aux tanks may not be legal in some states.

I will get a picture or two, but it will be next week.


When I was researching legality, IIRC, you could not drive while feeding from one to the other. What you could do while you are stopped was an entirely different matter. Hence, I control feed from one tank to the other with a manual ball valve. I can not change its position from inside the truck. I have to get out and turn the handle.

Gravity feed tanks are supposedly not legal in a lot of states.


You could check with RDS Aluminum in Florida about the 6 way switch also.


I personally went with the Idle_Chatter method and am extremely happy with the way it worked out!http://www.dieselplace.com/forum/smileys/Clap.gifhttp://www.dieselplace.com/forum/smileys/Approve.gif

After you have crawled around in the dirt and get covered with diesel fuel becasue of failed valves on a non gravity feed tank....I don't care if it is legal or not.

You require a DOT approved tank to have fuel flow from one tank to another.


You require an automatic fuel shut off.


Gravity feed is not acceptable.


Tractor Supply are only approved as a holding tank, and if you look there isn't a DOT sticker on any of their tanks.


And watch for crush zones on the truck, the GENERAL didn't and his auxillary fuel tanks BLEW UP.


good luck

I appreciate all the comments, and the concerns about legality. However, I am more concerned about keeping this amount of fuel fresh when I am not doing a lot of driving and may not need to fill this big tank for several weeks!


Should the tank be vented? And if so do you need some sort of dessicant air filter on the vent?


Or, assuming installation as a transfer tank, should I put a valve on the vent and close it when not actually transferring fuel to OEM tank? What do the "store bought" transfer tanks do in this instance?

I sprung for a Transfer Flow 50 gal in the bed tank with there Trans trac fill system. The system works great but it is $$$$. This system pumps fuel into fill neck of oem tank. I put a filter into that line so I could get 2nd filter on truck with out having to cut fuel lines. This way I only fuel up into aux tank and fuel gets extra filtering.

dirty old man:

The best thing I would do to keep the fuel fresh is to use some Sta-bil fuel stabilizer. (purchase at wal-mart, etc.) I have used this in a diesel shop heater (with fuel in it) & the fuel was good from around the 1st of March till the next November & started right back up with no problems. I also use stabil for winter storage on my boat & any gasoline I have stored in tanks. Since I started using the stabil (about3 yrs), I have not had any problems with "sour" fuel or shellac in my gas/diesel engines.

Your main problem will be condensation inside the tank if the fuel is left for a long time. Hot & cold temp fluctuations (in some cases, even over night) promote water condensate on the insides of the tank & you may have to keep an eye on your water separator.

For storage, a desiccant vented cap would / is always a good investment, as well as a good shut off valve for the extra tank.

The one thing that would give you some peace of mind as far as fuel cleanliness would be is a good secondary fuel filter (in the 2um range). I could not tell/remember if you have a secondary filter, but if you don't, they sure do give a guy peace of mind on the road when you have to fill up at "unknown" stations.

I hope this helps somewhat!

PDS
(edit fur spellun . . . )Edited by: Aggie91

Here's my setup. Its gravity feed also. The tank was custom built at Greer Tank in Anchorage, AK. It holds 60 gals. Pics of the ball valve were taken before I had Line-X done. Had them Line-X the front of the tank for further protection. I cut the filler neck in half and put in a piece of black pipe with a nut welded on and a hole drilled through the pipe body through the nut. My barbed nipple fitting is screwed to that and the hose is slid on with a hose clamp.


http://pic13.picturetrail.com/VOL487/437876/777914/34406771.jpg


http://pic13.picturetrail.com/VOL487/437876/777914/25620696.jpg


http://pic13.picturetrail.com/VOL487/437876/777914/24919801.jpg

A way to keep the fuel fresh would be to always fill the main tank from the aux tank. That would keep fresh fuel flushed through the aux tank continously. If you had a good filter between the two, then you would be in effect double filtering the fuel. The comment on legality was only to inform you, not make judgements.

A64pilot, I did not take as a jugement, but as FYI. One way around that is as I saw on a truck used to haul RV trailers out to dealers.


He had a 12 volt pump on the tank with a quick disconnect fuel hose he used to pump the fuel into truck tank. However the pump, hose, and nozzle do add to the cost.


Someone asked about filtration, and I do have a Nicktane w/Cat 2 micron filter. Giving some thought to some sort of filter between aux and reg. tanks. Maybe 10 micron?

dirty old man, I'm the guy you'll sometimes see with a 55 gal in the back and a siphon hose stuck in the filler neckhttp://www.dieselplace.com/forum/smileys/Big Smile.gif. Haven't done that in quite a while though.


Pumps aren't that expensive and provide enough pressure to push fuel through a filter. If you filter, why not go to a 2 micron? although 10 is probably plenty and I do like the 2 stage filter thing myself, was working with someone to develop an adapter to put a 2 micron Racor on the stock filter base, but I haven't heard from him in a while now. If you pump you may want to include a timer in the circuit so you don't forget.

New to this form. I am looking into how to hook up an aux tank. Lot of info here.


I have discovered, by accident, that leaving the valve open, even with the extra tank full, will not cause the stock tank to run over. Posted by Houston D Max is something I was wondering about.


I ahve a few questions. Maverick; In your pictures it appears you have connected the top and bottom of your tank together through a small hose. Why"

One more question' If I gravity flow to lower tank will it work if I put an inline filter in the line?