Hey guys and girls, I’m looking for feedback from those that have auxiliary fuel tanks. I know this topic has been the subject of several threads and I’ve read everyone I could find, but please hear me out. Let me describe what I’m thinking of installing and then you can blast away. I’m also looking for recommendations for the components. I have a 2017 F350 long bed with a Bakflip bed cover, so the tank must fit below the cover. I’m looking at the ATI AUX 46 gallon gravity feed tank. The ATTA 45 gallon tank will also fit but it is $200 more and cannot be purchased without one of ATTA’s pump feed system which add $300-$500 dollars to the price. Their pump systems are probably very good, but I don’t want to cut into the factory wiring or have to mount a switch/gauge console in the truck cab. I’ve decided on a gravity feed system (sort of) with a fuel filter and a solenoid valve. But I’ve read that some folks have discovered that adding a fuel filter and a solenoid valve has added enough restrictions that the gravity feed just doesn’t have sufficient head pressure (especially as the auxiliary tank level drops) to push much fuel into the main fuel tank. To help the flow, I plan on a using solenoid ball valve which is supposed to be less restrictive and operate cooler than a normal solenoid valve. So that leaves me with leaning towards adding a fuel pump also. I don’t have clue as to what pump would work. Since it will pull fuel from the bottom of the auxiliary fuel tank (unlike the top of the tank like the ATTA system), I don’t think it will require a very high capacity pump. Also, I really don’t want to keep the solenoid valve energized for long periods of time for gravity feed. I will wire the solenoid valve and fuel pump to one of the upffiter switches. My idea of operating the system will be to energize the solenoid valve/fuel pump when the main fuel tank drops to about ½ tank and dump some fuel into the main tank. I know I’ll have to play with this some to determine how fast the pump will transfer fuel. And I’ve also read that the main tank fuel gauge does not react very fast, so I will limit the time the pump runs to make sure I don’t overfill the main tank. And then finally, I want to install a ball valve to bypass the fuel filter/solenoid/fuel pump in the event any of the three fail. Ok folks, fire away. Tell me where I’m wrong. And again, any component recommendations would be greatly appreciated.

Thanks in advance.

 

 

Thanks for the response. Dang, that is COLD!!!! What is the dessert kit and tipube? And what fuel filter are you using?

 

 

I have a 37 gallon RDS tank. I plumbed it into the main tank vent line and use a fuel pump and a solenoid valve. They are wired to upfitter switch #1 to a timer that allows the fuel to flow for about 8 or 9 minutes thus pumping about 12 gallons into the main tank. I taped off of the draw tube on the aux tank, not the bottom drain.

I've written this up on this forum and included photos. You can probably find it by searching on my user name.

It works well. The timer is adjustable; I only activate the switch once I am just under 1/2 full on the main tank. The approximate 1 gallons brings the tank up to almost full.

 

 

I have a 60 gal RDS with ball valves and 12v solinoid, all the lines are 3/8 and the ball valve is also 3/8. I leave it on all the time or until the main starts to go down.

 

Can you give us info on the timer? What part number it is , how did you install it? etc.

 

Same here, works great no pump

 

Those with a 2017 (or probably later), did you have to remove the metal fuel filler neck and cut a section off of the end? Or were you able to connect the aux tank tee onto the end of the filler tube. I would rather not have to remove and cut unless necessary.

Thanks

 

I removed and cut. 6 inches off I think

 

Thanks, that's what I was thinking. It feels like 3 nuts holding the fill tube on?

 

Three screws up top, and the clamp below

 

Here are photos of the timer set up and the (very rudimentary) schematic.



The relay is a standard 12v, 30a relay. The timer relay board is from Amazon:
I am thinking of putting in either a momentary switch to activate the timer in case I forget to turn off the upfitter switch. As it is now if you leave the switch on it will activate the pump everytime you restart the truck.

oh - I also have an amber LED I put on the dash in the bottom of my instrument cluster that stays lit when the pump circuit if active.

 

I have a KSH custom-shape 60gal tank that fits under the Retrax canister and extends about 20" from the bulkhead. It has a pump controlled by the #1 upfitter and draws from off bottom from the top. Uses a pump similar/same as the Carter pictured above. No timer, but have left it on too long and filled the tank--does not build enough pressure to leak out the cap or the connections--a timer would certainly prevent this. Has a simple inline filter. The pump rate is noticeably slower as the level drops in the tank, and it won't empty completely. Yes, the fuel gauge is slow-reacting, but even when the blue bar reaches the end of the gauge, there is room left in the tank. So, whatever gallons your tank holds, it won't empty unless you get a better pump or draw off the bottom......been lots of comments online about it now being illegal to run gravity-feed tanks. Ran gravity-feed tanks on previous 2 450s, without a solenoid cutoff----one morning at a motel in LA, as I left for work, there was a track of diesel under my truck into the asphalt--one of the hose clamp fittings had come loose and I had forgotten to close the manual valve.
Overall, it is a needed add-on for my heavy-towing----besides giving me a lot more distance between fueling, it allows for choosing prices and fueling when the fiver is parked.