Aux bed tank

[Sailor Mike]

I have some questions about aux fuel tanks for those of you that have or have had them:
1. Is it common to see them setup to pump directly to the main fuel tank? If so does a kit exist? If not, why?

2. Most everything I’ve seen is for diesel applications, I’m thinking about adding an aux tank to my gas 2500 HD. However, before we get all fired up, I believe I understand the difference between a combustible and a flammable and I also believe I understand the legal ramifications if something bad happens.

So, If any of you have done just what I’m thinking about doing I’d like to hear about it. If you just want to tell me I’m an idiot, well that’s fine too.

Here’s what I’ve got: 2007 Chevy Silverado 2500HD 6.0ltr
What I want to do is mount a 20 or 30 gallon tank in the bed and wire up a 12v pump that pumps from the drain plug of the aux tank to my main tank. I’d like to wire it to a toggle switch in the cab. I can’t think of I reason why I can’t make this work safely.

[LarryDAnders]

I've used auxiliary fuel tanks from Transfer Flo for about 20 years now. First for gas and most of the time for diesel. I have a 50 gallon in bed tank that takes up a couple of feet of floor space in the front of the bed. It is low enough that my tonneau cover can close over the top of it. It comes with a pump, hoses, hose adaptor and wiring to hook it up. It monitors your main tank fuel level and fills it as needed, keeping the levels balance at about the same fuel level as they both are emptied. You simply plumb the pump into the rubber fuel tank fill hose with both an in and out connection, adaptor for these connections is provided. The out connection protects you if the pump didn't stop pumping when it was supposed to, so you'd never overflow your main tank. I've never had an overflow problem, it just works. So with a 36 gallon main tank and my 50 gallon aux. tank, I can go a long ways without stopping for fuel. I've never had a problem with these systems and I've had them in 3 trucks. Today I have it installed in my 2005 HD2500 Silverado, 6.6 Duramax, Allison 5 speed, ext. cab, long box truck.

[bluefishgary]

Hi I have a 3500 Ram CC DRW. Its a gas 6.4 I use a RDS 60 gal fuel tank with
tool box, it came with a fuel pump in the tank. On a trip I stop at a rest area
and fill the truck up,then back on the road. You can NOT gravity fill a gas tank
or the check engion light will come on, it has to do with the emission.
So my total fuel is about 90 gal, I get about 9 mpg so plenty far for one day.

[funjnt]

NO NO NO! First off you need a DOT approved tank to haul gasoline. Second you should never hook up any fuel source to the bottom of the tank for obvious reasons. Third if you use a manual pump use a spring loaded switch so you don't for get it's on (ask how I know this). We created a diesel fuel slick all the way through Lake Placid in a friends truck who got talking and forgot his switch was on as your saying. Fuel overflowed and we coated the roads for two miles. Luckily we didn't get into trouble with being right on the lake.

Ditto on the Transfer flow. We have a transfer flow tank in our Kodiak for pulling horse trailer. It is the best way to go. It is automatic and designed for this application. Go to their website and check them out and see if they are able to be used for gas. This may be a good reason to trade in for a diesel!

[SmokeyWren]

Originally Posted by Sailor Mike

1. Is it common to see them setup to pump directly to the main fuel tank? If so does a kit exist? If not, why?

It's illegal for gasoline but okay for diesel.

What I want to do is mount a 20 or 30 gallon tank in the bed and wire up a 12v pump that pumps from the drain plug of the aux tank to my main tank. I’d like to wire it to a toggle switch in the cab. I can’t think of I reason why I can’t make this work safely.

Illegal to make it work automagically the way an auxiliary tank for diesel works. But easy to make it work as a "refueling tank". Not by using the drain plug in the bottom of the tank, but by using a 12-volt pump that sucks gas out of the top of the tank and sends it down to the stock gas tank.


And not automatic. You have to start and stop the flow, perhaps at a rest stop or a WalMart parking lot. TransferFlow is the experts at doing it safely while complying with the law. Not cheap but done right.
https://www.transferflow.com/shop/product/0800109417

[bluefishgary]

On mine I use the fuel pump to fill my tractor 8N. It has 10 ft of hose but works great for the tractor. The RDS tank/tool box is rated for GAS and DOT approved.
It also works for the snow blower. ( dont like that machine). At 9 mpg i go about 250 miles then just refill the truck .Easy peess

[Superburban]

A couple of areas I have seen people get in trouble with those tanks.



A lot of counties and states consider them as portable refueling tanks, and require markings, spill prevention, and fire prevention devices/ plans. Many also have strict regs on where you can refuel a vehicle from portable refueling tanks.



As portable refueling tanks, when you cross a state border, you are importing untaxed (by that state) fuel into the state.


EPA rules state that whoever is transporting a substance that contaminates the ground, is responsible for the cleanup, regardless of who caused the spill. Will your insurance cover the several thou$and dollar bill to pick up, and haul away contaminated earth? Likely not, unless you have the storage tank listed as a rider to the auto policy.


Yes, 99% of the driver using those tanks never get in trouble, but that does not make it legit, and not an excuse to ignore the laws. It is still a portable refueling operation, regardless of whether you are refueling a privately owned vehicle, or construction equipment.


Directly connecting a bulk storage tank to a vehicles fuel system, opens up another can of worms.

[Sailor Mike]

Thanks for the advise guys, if I decide to install an Aux tank, I’ll be following the rules. DOT approved tank and a gas station style pump nozzle, the rules are in please for a reason. Hate to get someone hurt.

[Nlambert]

I ran a Transfer flow 40 gallon tank in my F250 and absolutely loved it.

Below is the tank I had:
https://www.transferflow.com/shop/product/0800116188

I ran the TRAXII monitoring system in the cab which determined at what point the pump should turn on and refuel the main tank. I have gone as far as 1,400 miles before a refueling.

It malfunctioned once well outside of warranty and would cause my fuel gauge in the cluster to drop to E periodically. I called Transferflow anyhow and they sent me the complete wiring diagram and then walked me through the repair on speakerphone while I did the work. If the repair didn't work they were going to send me a new wiring harness (for free). Turns out the ground to the frame had gotten loose. Their customer service is fantastic.

If I decide to do another aux tank it will 100% be a Transfer Flow.

[funjnt]

Ditto again on transfer flow. Again, ours is awesome. Shows both tank levels and combined fuel level. Also has trax monitor. Seamless and flawless to operate. I would strongly consider this system.

In my eyes as I also have in bed fuel tanks, what is the benefit of manually filling the fuel tank with a nozzle other than traveling way off grid. The nice part of transfer flo is it just keeps putting fuel in tank automatically and thus you can keep rolling. For us and the horses this works great as we could only go about 200-250 miles per tank and stopping that often was a big hassle.

[traveldawg]

I have an RDS 37 gallon aux tank in the bed. I wired an electric valve and a fuel pump to a timer circuit. When I get below a half tank on the main I flip a switch and the pump runs for about 8 minutes transferring about 12 gallons to the main.

All that is fine but with an aluminum bed I have to run a dedicated ground rather than rely on the bed as a ground. I suppose the aluminum body is a bit isolated from the steel frame.