Fuel transfer tank and pump questions

[JVantreese]

I have been using a gravity feed system for over a year with no problems. I used the check valve that Northern sells to put in the oem fill hose. You do need to make sure that your oem fuel cap seals well and that your vent hose on the oem tank is not open to the atmospher. I routed fuel line of the two oem vents to a tee to get to a single line that is routed back to the top of the aux tank. I used a tee at the top of the aux tank to continue the vent line about 12 inches above the aux tank. My capper top has side windows that flip up so I fill my aux tank via the window opening. The height of the 80 gal tank is just below the pickup's side rail so I use a peice of plywood to make a shelve that covers the tank top. I made a round cut out for the aux tank fill cap and a cut out to be able to reach the shut off valve for the aux tank. This high and dry shelve is handy for anything from suitcases to smaller tool boxes.



I chose not to use any aux filters as I look at the aux tank as a big fuel can filling my oem tank and the oem tank has a filter. If I ever add an aftermarket fuel filter it would be placed between the the oem tank and the pump.



I find that the added 80 gal tank is both a money saver and a feel good add on. Last week I was coming back from Ann Arbor and stopped at a Flying J near Saginaw to fill up at 3. 289. Our best price in Petoskey was and is at 3. 459. It is also nice to know that I have 100 gal draw down before I need to start looking for a fueling station.

 

[steved]

I'm running a small spin-on filter between the aux and the main tanks. I had over 30k on this last one and it was still flowing pretty good. My system is a siphon/gravity with a pump assist, and it has worked well for a year. Even siphoning through the filter. It only occasionally won't keep up, and I attribute that to either lost siphon or thicker fuel (cold weather).



I found that on a siphon, it will fill the main tank, but not overflow. However, if you pump to the main tank, you can push fuel out the roll over valves (even with a return/vent line between the main and the aux tanks). I would not worry about a gravity system overflowing a main tank... as long as everything is in good working order.



I view the aux tank as a first line of defense against contaminated fuel... dirt and water are hopefully caught before they get into your main tank/fuel system.



My only added bit of advice would be to not only install a shut-off valve, but a set of quick connects as well... makes removing the aux tank a lot easier! I am using a set of hydraulic quick connects, 1/4-inch NPT @ 3GPM.



steved

 

[JCasper]

I am kinda thinking about one of these. I like the look of diamond plate versus the white ones. I just wish I could find one local to me so I wouldn't have to pay $100+ for shipping.



Tradesman 48 Gallon Aluminum L-shape Liquid Storage Tank



I am not familiar with what the top of the tank looks like, but I will have to look to see how to go about plumbing it in. That way what you guys are all talking about will hopefully make some sense.

 

[steved]

I am kinda thinking about one of these. I like the look of diamond plate versus the white ones. I just wish I could find one local to me so I wouldn't have to pay $100+ for shipping.



Tradesman 48 Gallon Aluminum L-shape Liquid Storage Tank



I am not familiar with what the top of the tank looks like, but I will have to look to see how to go about plumbing it in. That way what you guys are all talking about will hopefully make some sense.

That should have two 2-inch bungs in the top... one is the fill, the other is the vent. There should be at least two 1/2-inch or 3/8-inch NPT bungs in the bottom (sides). Simply hook into one of those bottom bungs and gravity fill the main tank.



steved

 

[JCasper]

That should have two 2-inch bungs in the top... one is the fill, the other is the vent. There should be at least two 1/2-inch or 3/8-inch NPT bungs in the bottom (sides). Simply hook into one of those bottom bungs and gravity fill the main tank.



steved

Does someone make an electric solenoid that you can open and close with a switch? That would work pretty slick for controlling the gravity feed.

 

[GFreshour]

I bought the tank install kit from Northern when I bought the 91 gal toolbox/tank combo, 1 90 degree brass fitting from the hardware store, and installed it gravity feed. I have had NO Problems to date, and the install kit makes it amazingly simple. No electronic hook ups, no additional filters... . nothing, nada don't overcomplicate it. You will know when you are down to your last 35 gallons when the fuel gauge in your truck moves off of full.

 

[DLane]

I have run a 100 gal. aux tank since 88. Same tank in all my work trucks. I have plumbed it grav. only, grav. with filters, and now have it set up with a pump and filters. I would never again plumb one gravity only for 2 reasons. (1)The fuel today is too dirty, or maybe our injection systems are just "more fragile" but more filtration is a good thing. Mine is set up with a water seperator and 2 mic filter before the factory tank. The first line of defense as steved correctly stated.

(2) I have had problems with the fuel return having no where to return when the factory tank is gravity fed and always full. This caused my factory filter cap to vibrate lose due to the high pressures and leak any fuel cost savings right onto the ground. I use a old "carter" style pump from my 2000 that was only hitting 6psi when on the truck. These pumps allow a small amount of fuel thru when off. Has worked very well in this application. I have a shutoff valve at the tank and one more between the pump and factory tank. The shutoff between pump and tank is how I control flow. On long trips if the factory tank is half tank I open the valve and drive, fuel level rarely rises or falls. (if it happens to fall because of the load I have or a big headwind, I can catch it up easily with the pump) For daily driving I fill the factory tank and close the valve.

It only takes one time losing 90 gallons of fuel out the fuel filter cap to wish you had done things differently

 

[Hoefler]

I don't like gravity feed for the above mentioned reasons, and in many states it is illegal as well. I used a Carter in line turbo pump and filter on a top feed tank. I fabricated my pickup out of brass fittings and a steel brake line. It sits approximately 1/2" off the bottom. I installed 2 in line glass cartridge filters, one in the supply line and one in the return line. They are near the pick up and return fittings on the tank, I can easily adjust my review mirror to see them when transferring fuel. The pump will not pass any fuel when off. When on, the supply filter will have fuel in it, when the main tank is full, the return filter will have fuel in it. No fuel in either filter, tank is empty.

 

[steved]

I know they make electronic control solenoids... probably look through McMaster-Carr or Grainger to find what you need. I would either get one that is powered both directions or normally closed (so that you are sure it stays closed if the power is lost)...



As for not gravity feeding... I've actually had MORE problems running a pump between the aux tank and main tank, than I would have simply gravity feeding. You can very easily overpressure the roll-over valves with a pump (and that is with an open vent line between the main tank and auxiliary... it should have fed back that line!!!). I have never had the cap back off (only had this tank in a year, or around 40k miles) or any other leaks from simply siphoning (gravity).



If I was to do it again, I'd probably go with a bottom-feed tank (not a top feed like my fuel cell), with a pump and filter... I like being able to "top off" the main tank with the pump when fueling, so that you have the same amount of fuel each time. But I dislike losing the siphon, especially when the aux tank gets low (fuel slosh)...



steved

 

[Gary - K7GLD]

Does someone make an electric solenoid that you can open and close with a switch? That would work pretty slick for controlling the gravity feed.

I use both a Carter pump and an electric dual-tank flow control valve on my transfer setup - I use the port that the internal solenoid opens when activated for fuel flow - it is switched on when the pump is activated - and when switched off, that shuts off both the pump and fuel flow thru the valve. Should be a common auto supply item...



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[JCasper]

Any of you know anything about this new Transfer flow that they have?



40 Gallon Toolbox Tank



Not a bad price considering it has a pump and all. It just doesn't have the controller in the cab, it's all automatic.

 

[JCasper]

This is a bit cheaper then the transfer flow and has a decent size toolbox on it.



Auxiliary Fuel tank and Toolbox Combo — 60 Gallon, All Diamond, Model# 71926 | Auxiliary Fuel Tanks | Northern Tool + Equipment



I wonder if I could just use a Electric solenoid and no pump and let it gravity feed through the solenoid out of the drain plug in the bottom?



Or I could get this and just put it under my Pro-tech box.



Rectangular Auxiliary Fuel Tank - 37 Gallon, All Diamond, Model# 71804 | Auxiliary Fuel Tanks | Northern Tool + Equipment

 

[Scrappy]

I have a 78 gallon L tank that gravity feeds in mine. from the upper tank it goes thru a ball valve to a 10 micron spin on filter then to a valve like Gary K7GLD is using and finally to the factory tank.

the valve is a fuel tank selector valve out of a Chevy pickup.

when I get to 1/2 tank I flip a switch and let it transfer until I get to around 3/4 tank. I have had no problems with the transfer rate with my setup even while towing.

I can drive 1100+ miles towing getting 12 mpg. It is great not having to stop for fuel, now it is the "other" tanks that fill up that I base my stops on.