Another aux fuel tank thread

[cksh8me]

I read this on another forum and it sounds like a good idea to me. There weren't many responces so I'm posting it here to see if this is possible to do.



I'd like to add an aux fuel tank between my rear fender and frame rail.



My question is would it vacuum feed if I tied the vent hoses from the main tank to the aux tank?



There has to be some kind of ventilation for the main tank. My thoughts are move the vent hose from the main tank to the aux tank and then run a transfer hose from the aux tank to the vent hole in the main tank.



The two things that would kill this idea are 1. If I need a fuel pump to move fuel between the tanks. 2 The cost of the tank vs how many gallons the tank will hold.

 

[Hoefler]

The tank vent is in the fuel fill cap. It is designed to be a one way vent. In the summer the tank will actually build pressure. I installed a small turbine pump to transfer fuel from my auxiliary to the main Pump, plumbing, and wiring cost me less than $100.

 

[Camelracer]

There is another vent in the top of the fuel pickup module. It has a valve that closes with a full tank or rollover but is open to the atmosphere as the fuel level goes down.

 

[cksh8me]

It looks like I'd have to find a sealed fuel cap.



Hoefler is your tank in the same position or a bed mounted tank?



Thanks



Camel Racer that might be one point to plug the aux tank into or I'd have to block it off.



Thanks



Doing this stuff was alot easier when I was a kid.

 

[Joe G.]

Which truck? If it's the '97 you can use a tank selection valve and the stock lift pump to move the fuel.

 

[cksh8me]

No this is for my 04. 5. The more I find out about this truck the more I like my 97

 

[Hoefler]

It looks like I'd have to find a sealed fuel cap.



Hoefler is your tank in the same position or a bed mounted tank?



Thanks



Camel Racer that might be one point to plug the aux tank into or I'd have to block it off.



Thanks



Doing this stuff was alot easier when I was a kid.

It is bed mounted, with a top feed. I don't like gravity feed, and is illegal in many states. I brazed pipe fittings on the filler neck and plumbed from the aux to the pump mounted under the bed to the fill side of the neck. Then I plumbed the vent side of the neck back to the aux. I have two of those clear glass filters with the cleanable screens plumbed into the supply and the return lines above the aux so I can see them in my rear view mirror. When the return filter is full, the main tank is full. When the supply filter is empty, aux empty.

 

[Buffalo]

JoeG.



Remember that you need returns for both tanks. Pollack makes a 6-way elec. valve that allows you to do this with an elec. switch. Works well.



Joe F.

 

[Joe G.]

JoeG.



Remember that you need returns for both tanks. Pollack makes a 6-way elec. valve that allows you to do this with an elec. switch. Works well.



Joe F.

Not so. I'm using the stock lift pump to move fuel from the aux tank to the main tank. I do that by using the stock return on the main tank. That way when the aux tank is selected any fuel not burned (most of it) will return to the main tank. This system really moves fuel! A selection valve with two inputs and one output makes this work. I tried some electric pumps to move fuel from the aux tank to the main tank, but they proved less than reliable. The stock 12 valve mechanical lift pump is almost bullet proof. My aux tank is removable if I need the bed space.

 

[Buffalo]

JoeG.



I guess I don't really understand how your set-up is plumbed. Obviously, it works & that is all that matters. Can't beat success!!!



My aux. tank is from Dually Depot, in Elkhart, IN. Basically, the engine draws from one tank at a time. It "pulls" & "returns" to which ever tank is being used. If you pulled from the aux. tank & returned to the main tank, in no time you will have an over-filled condition in the main tank from the returned fuel. That's where the Pollack valve comes into play. I have a rocker switch on my dash & you decide which tank you want to pull from, & that's it. Works well.



I guess there is more than one way to skin a cat!!!



Joe F.

 

[Joe G.]

I've developed a tank controller to avoid over filling the main tank. It switches to the aux tank when the main tank is half full and switches back to the main tank when it's almost full. Before I built that I overfilled the main tank a few times and wasted fuel on tailgaters. My fuel system is pretty simple. I use a saddle tank from a dump truck that I bought at a scrap metal yard for $35. It holds 50 gallons. I put the tank selection valve near the engine so I could replace the supply hose with a hose to the tank selection valve normal input and a line from the aux tank to the other input. No other changes to the stock fuel supply system. Cheap too.

 

[HWestfall]

I have a 70 gal. aux. tank under a tool box in the bed. I use the stock transfer pump mounted on the frame to move fuel to the main tank through the vent hose between the fill and the tank. I put a electric shut off between the tank and pump because the fuel runs through the pump. It is connected to the pump switch. It works great. HWestfall





02 3500 Patr. Blue, KC Lites, Chrome Brush Guard. Spray in bed liner. PacBrake. Isspro gauges. ABE Stage One,

 

[cksh8me]

Thanks, Guys.

 

[RickL]

This is something worth checking out. Especially if you don't want to lose bed space. Mine is a QC/SB, so there isn't much available in the way of aux tanks.



Tour Buddy - "Your gas station on the trail" Auxiliary Fuel Systems for your Dodge Diesel Truck