Auxiliary Gas Tank in Bed

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AFMoulton

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John Jensen

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Ok, well I guess I can explain it to you/answer your question, which I’ve already done.

You made a claim of something really bad happening due to someone not following rules/guidance from manufacture.

Someone asked you for a link, you said “Link? Why need a link?”

Well maybe they wanted to read more about the specifics of the situation. You could have simply answered their post with, “I don’t have a link, it’s a personal story that happened to someone I/my son knows”

So yeah it becomes a credibility issue when you answer that way. Most of us come here to learn, and when someone makes a statement to the level you do, we want to learn more.

Sorry if you feel it’s an attack on your integrity, but agains no one here knows you from Adam, and I personally don’t just “take someone at their word” on the internet. That is the problem with this country to be perfectly honest, they see something on the internet and “ITS THE TRUTH!”


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Well, now you have met someone with whom you can trust.
 

68PowerWagon

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Well, here's a final update.

If my math is correct, I figure the weight of a full tank of gas plus the weight of the tank itself is about 500 lbs. Tank dimensions are 56" x 13". Ribs and valleys of liner are roughly 1/2" each. Pressure of tank on liner is about 5 1/2 lbs/sq. in. I doubt that is anything to worry about. I certainly won't.

I took the advice and used a pipe thread compound that is impervious to gasoline and it's also aviation approved for those times when I feel like getting some air in my 7500/8000 lb. truck!

I took my tank to a radiator repair shop and had them weld an extra **** where I wanted it. I didn't know if the "diamond" would interfere with the placement of the **** so I marked two locations. They were confused so they welded 2 bungs where marked. No harm, no foul!

All is well, no leaks. Works like a charm. Doesn't overfill the OEM tank. Doesn't overflow the OEM fill tube. It simple works.

I did add another ground strap from a tank mounting bolt to the factory ground bolt. Likely not needed as the 3 mounting bolts already provide a ground. But it can't hurt. View attachment 178067 View attachment 178070

View attachment 178073

Tumbleweed... I am still toying with doing this project over the winter. Everything still working out well for you?
 
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68PowerWagon

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Also what vendor did you use to get one that cheap? I don't think I want one that big, but I would like one that cheap! :D
 
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Tumbleweed

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Also what vendor did you use to get one that cheap? I don't think I want one that big, but I would like one that cheap! :D
Everything is working real well. I wouldn't change a thing.

I bought it from RDS via Amazon. I did have it in my "Wish List" for a few months. Sometimes prices will drop when you sit on an item for a while. This time it did.AUX tank receipt.jpg
 

2003F350

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Commercial use has different regulations than personal private use. I'm not a lawyer so I can't speak to the legal ramifications. I have never seen the regulation prohibiting gravity feed to the OEM tank.

Places around here still install these tanks with gravity feed in personal-use trucks.
 

68PowerWagon

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Everything is working real well. I wouldn't change a thing.

I bought it from RDS via Amazon. I did have it in my "Wish List" for a few months. Sometimes prices will drop when you sit on an item for a while. This time it did.View attachment 188569

Stupid me! :happy175: On your original post I seen dropped $145 & thought that was the price! :rolleyes: Should have know that was too good to be true!
 

Tsys100718

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Well I've read a bunch of threads about folks wanting an auxiliary gas tank in the bed of their truck. While numerous options exist for the diesel crowd, none seem to exist for the gassers. I used to have a 54 gallon tank in my diesel dually. Loved the extra range and the option of buying fuel where and when I wanted, rather than when I needed to.
So, I bought a 60 gallon RDS tank, 71212 56" Length x 13" Width x 19.25" Height Rectangular Auxiliary/Transfer Fuel Tank, from Amazon. I had it in my "Wish List" and when the price dropped $145, I pulled the trigger.

I mounted it offset to the passenger side so I would have more room for a valve and fittings.
I routed the vent hose to a tee I installed in the OEM vent line so there would be no fumes lingering around. I then welded a tube to allow the aux tank to gravity feed into the OEM tank's fill tube. I added an inline gas filter between the aux tank and the OEM fill tube.
It has been a couple weeks and only one small problem so far. Once the OEM tank is full the gravity fed gas will drain into the OEM vent line. This has caused the truck to stall 3 times. My solution for now is to only open the valve when I need the gas and shut it off once the factory tank is full. There seems to be no long-term ill effects of the excess gas draining into the vent line.
View attachment 168937


A little tube cutter took care of the vent line.
View attachment 168938


The tank is secured via the mounting tabs. The ratchet strap is just for a little extra security.
I do wish that the **** was welded at the rear of the tank to allow for easier plumbing, more room for fittings.
View attachment 168939


EXCEPT for the fact that it's ILLEGAL to plumb gas straight into the filler tube. That's the reason it's difficult to find an Aux tank actually RATED and legal for gas. If you read and actually adhere to the descriptions of MOST available tanks they explicitly say "Not for Gasoline use."

I had a 46 gal tank mounted in the bed of my 2017 1500 and a pump with a nozzle attached. While visiting the Grand Canyon, a LEO noticed me filling my aux tank and scrutinized my setup. Since I had the proper placards and a separate system, he said it was ok. So whenever I got close to empty, I'd pull over and insert the nozzle and turn on the pump. Worked great, though a bit of a pain at times.

I recently bought a 2500 diesel and will hook the old 46 gal tank up for gravity feed with a solenoid and a pump.
 
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AFMoulton

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Thank you @AFMoulton.

I suppose I could always splice in an in-line fuel pump if I thought it was necessary.

It still only says commercial vehicles, so if you are private use only DOT/LE can’t really do much to you. IMHO. If it works for you and you don’t have issues, stick with it.


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Tumbleweed

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Yep, private use only. I do like only filling up once a month. And that doesn't include the long towing drives.

It's been nearly one year. No issues whatsoever. Even the issue of the "Gas Cap" dash light was unrelated to the aux. tank. Never smelled/smelt? any gas fumes. It simply works.

BTW, while looking over the evap box, I noticed that my OEM gas tank could've been about 3 feet longer. Maybe another 8-10 gallons? Maybe if I had that, I wouldn't have had to add the aux. tank?!?!
 

John Jensen

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I think he’s referring to this law. Which clearly states “Applies to commercial vehicles”

But this guy doesn’t post links to back up his claims, as seen previously in this thread.

https://www.law.cornell.edu/cfr/text/49/393.67

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Ok -the challenge is on. "This Guy" as Moulton posts so negatively about, will help you understand. Here's the law for Tumbleweeds "private use".
https://www.govregs.com/regulations/expand/title49_chapterIII_part393_subpartE_section393.65

And if you want Cornell's version, who you quoted:
https://www.law.cornell.edu/cfr/text/49/393.65

You are quoting 393.67 which is the law for commercial owners, not private use. But go ahead and use whatever law you want, you know best, I was just trying to help you - never again, I promise!.
 

2003F350

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Quoted directly from the Cornell source:

"(d) Gravity or syphon feed prohibited. A fuel system must not supply fuel by gravity or syphon feed directly to the carburetor or injector."

Nowhere does it say it can't gravity feed into another tank. Just not into the carb or injector.

The only thing I see that REMOTELY resembles gravity feed to another tank being not allowed is the following:

"(5) Fuel withdrawal fittings. Except for diesel fuel tanks, the fittings through which fuel is withdrawn from a fuel tank must be located above the normal level of fuel in the tank when the tank is full."

In which case, it means you can install a pump to fill your stock tank. Nowhere does it say it cannot be electric. The only statement about this fuel transfer is the following:

"(e) Selection control valve location. If a fuel system includes a selection control valve which is operable by the driver to regulate the flow of fuel from two or more fuel tanks, the valve must be installed so that either -

(1) The driver may operate it while watching the roadway and without leaving his/her driving position; or

(2) The driver must stop the vehicle and leave his/her seat in order to operate the valve."

EVEN THEN, there is this tidbit:

"(4) Drains and bottom fittings. (i) Drains or other bottom fittings must not extend more than three-fourths of an inch below the lowest part of the fuel tank or sump.

(ii) Drains or other bottom fittings must be protected against damage from impact.

(iii) If a fuel tank has drains the drain fittings must permit substantially complete drainage of the tank.

(iv) Drains or other bottom fittings must be installed in a flange or spud designed to accommodate it."

Which, while this pushes the definition of 'drain,' means if you had a petcock valve to drain the auxiliary tank that just HAPPENS to drain it into your primary tank, it could be allowable.

I could find NOWHERE in any of these that state you cannot plumb your auxiliary tank into your primary tank's filler neck.
 
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