TJE

I'v looked at these tanks in the store, but cant really tell the difference in them. Can someone tell the physical differences in them?

Thanks, Tony

Patriot_Auto

If you are wanting to know the difference between a fuel transfer tank and an auxiliary tank.

A transfer tank is only a tank that you can store/transfer diesel fuel in. You have to install a pump onto the tank in order to fill machinery or trucks. You CAN NOT (legally) plumb it into your existing fuel system.

An auxiliary tank is a tank that is DOT certified to be plumbed into your fuel system. Some come with a computer to pump fuel into your factory tank when the level comes below a certain point. Usually more expensive route. More permanent installation.

TJE

Thanks for the help. When I look at the tanks both of them have an outlet or drain at the bottom for fuel line! What is up with this, If it is not to go into your main tank?

The reason I'm wanting to know is, I can't see any real difference other than price.

Later, Tony

dadwolf2

Basically an aux tank automatically fills up the main tank. Different manufacturers use slightly different systems. A transfer tank you get out of the truck, pull out the hose, turn on the pump and fill up your tank.

haulin-rv

Its exactly that a drain on both. Many transfer tanks now do not have a drain to stop people from using them as an aux tank. A true aux tank will have 3 ports on the top, in, out and vent. I have mine plumbed so the fuel goes out through a pump then through a fuel water sep/filter then through a 2 micron filter and then to an adapter in the fill neck. Then there is another line going from the adapter back to the tank for fuel to flow back so you can not overflow the main tank. You can get a nice 91 gal aux diamond plate tool box combo from Northern Tool around $700 and then just add your own plumbing, filter, and pump.

OutlawStorm

Personally you dont need a pump to get the fuel to the stock tank. I have mine gravity feed to an electric switch then to a filter and then to the adapter in the main fuel neck. When main tank is low, i flip the switch and about 20 - 30 mins later tank is full and i switch it off again. Would never have a Diesel truck without an aux tank again, to many times when you are not on the main roads, small towns dont have Diesel or nothing open at night.

HiJenks

I've been using the 60 gal tool box combo from Northern tool for over three years.
I bought the dual switch and cut the main fuel line at the rear of the cab, installed an inline fuel filter in each line between the tanks and the fuel switch and connected the output back to the main fuel line.
The switch has all the electrical instructions for hook up to the fuel level for your gauge and the switch.
Works great!!

haulin-rv

Bad idea. Many have found you are stressing the lift pump even more than it already is. You are forcing it to draw fuel upward out of the aux tank. Thats why all the companies are now using fuel transfer systems instead. I had my original tank on my 24 valve that way killed a couple lift pumps.

HiJenks

I've relocated the LP to the rear so I doubt the lift is that bad.....the original position lifted fuel about the same or more from the OEM tank.

CrazyFloyd

Would love to get more detail on this set up. My 110 gallon just gravity feeds and I cannot just leave it. Having your set up would be perfect.

TRCM

How do you figure that ?? Once the line is primed, the extra height makes it easier to draw fuel from the aux tank in the bed due to the siphon effect of the fluid.

It is more of a stress to ALWAYS draw fuel up and out of the stock tank than it is to use the aux tank with the siphon effect helping it out.

Just like it is more work to siphon fuel out of a tank by NOT lowering the end once flow is established, cuz you would have to keep sucking instead of letting it siphon out.

The companies are using fuel transfer systems cuz it makes them more money, not cuz it's better for you.

OutlawStorm

I sent you a pm about my setup

FiverBob

Floyd,
What is the problem with leaving your setup. I have mine gravity fed and I fill up and can leave it turned on with no problem. I normally don't, but I can.

I have a write up in Tech Facts on installing an RDS system gravity fed. Since writing that, RDS developed an installation kit that is even easier to use than how I did mine. Love the setup. No wires, no electric valves, no additional plumbing other than one simple line into the filler pipe. Nothing to break and leave you stranded as I have been using pumped or electric valved systems.

Bob

TJE

Thanks guys for the answers you've provided.

I guess the thing I'm asking is this. Can I buy a tranfer tank, and feed it into my main tank when I'm pulling the 5th wheel? The reason I'm asking, if there is a difference in how the tanks are made, and a transfer tank wont work, fine. I just don't want to pay the difference in price for the same tank with just a different tag, or sticker on it, if the tanks are really the same.

Thanks, Tony

dadwolf2

I know there are a lot of guys who praise the Northern Tool/RDS gravity feed tanks and the price is hard to resist. It seems like nobody but a lawyer can determine if a gravity feed system is really legal. At the very least I would say that it's not legal in every state. "Some" have stated that gravity systems screw with the newer trucks computerized fuel systems. All I know is that there are too many unanswered questions for me.