Gravity aux fuel tank questions

kcmusa · 11-20-2020, 08:24 PM

For those who have a gravity fed fuel tank in their truck.

How does it work as far as dumping fuel back into the main tank?
Does it fill faster than being used?
Do you use a filter, a pump or a solenoid? If you do what kind, have a link?

I am asking because I am researching an aux fuel tank.

NJCorm265 · 11-20-2020, 08:39 PM

The kit should come with a one way check valve that goes on the filler neck above the tank I installed mine about 1 1/2 ago no issues I love it for on long hauls I ran from NJ to Knoxville TN pulling around 13,000 in my Cummins with a 50 gallon auxiliary tank one of best mods besides air bags

NJCorm265 · 11-20-2020, 08:42 PM

Just make sure to fill up the truck tank before the auxiliary tank if the ball valve is on

NJCorm265 · 11-20-2020, 08:47 PM

kcmusa · 11-21-2020, 08:35 AM

Yes I understand the kits.
Does the aux tank complete drain?
How fast or slow is the transfer?

ddphillips52 · 11-21-2020, 10:08 AM

Mine drains slightly faster than the truck can use it.

Jim34RL · 11-21-2020, 11:21 AM

Quote:

Originally Posted by kcmusa

For those who have a gravity fed fuel tank in their truck.

How does it work as far as dumping fuel back into the main tank?
Does it fill faster than being used?
Do you use a filter, a pump or a solenoid? If you do what kind, have a link?

I am asking because I am researching an aux fuel tank.

How much fuel capacity are you looking for? Have you explored a replacement tank that will replace the factory tank? Or have you looked at a Titan tank that will replace the spare tire and give you an additional 30 gallon capacity? This feeds directly into the main tank via a fuel pump that you control form the cab of the truck.

https://titanfueltanks.com/products/spare-tire-tanks

Before every complains that this is a bad idea because you need the spare tire! Will in the 12 years that I have own my current truck I have never needed the spare tire. The only time that the spare tire is lowered out of the area that the tire is stored in. Is to make sure that the cable will lower the tire, this is done once a year.

tinkerreknit · 11-21-2020, 12:20 PM

I'm not sure if this helps with your questions. I have a 20 gal RDS tank. It gives me a little more range, and allows me to better take advantage of my credit card fuel points. It won't quite keep up with the engine's demand, but that's not important to me. The extra fuel is there and keeps me from getting into tight fuel stations. I'll get a new truck soon, and I think I'll get a toolbox/aux fuel tank combo. I'll retire soon and I can fill up at the best prices. I hate fueling, and so I want to get lots of fuel when I do. My little tank has suited me well though, and takes little bed space.

tinkerreknit · 11-21-2020, 01:14 PM

I did put a cheap in-line filter after the tank. Because.. algae.

bradleyr001 · 11-21-2020, 02:02 PM

Can't imagine pulling without one after installing it. I have a 60gal aux tank, fill up truck tank, then aux tank, then open aux tank and tow... when the truck tank needle starts moving I know the aux tank is out of fuel, which is good for approx 550-600 miles, and now I still have a full truck tank. It's great to be able to go for almost 1000 miles before having to worry about refueling if necessary.

bobneal69 · 11-21-2020, 02:03 PM

I put in a 90-gallon tank. I consider it one of the best things I have done for traveling. I can go over 1,000 miles without fueling. This allows me to pick and choose where I buy diesel resulting in easy in and out and cheaper prices. I have a shutoff valve at the tank. If I leave the valve open while sitting for several hours I get a small diesel spot showing up under the truck, so I leave it closed except when traveling and I need the fuel. I often forget to open it when leaving so I'll open it at the first stop. Usually, my main tank is down to 1/4. Once I open the valve the main tank never goes down and will increase slightly while traveling.

Larry-NC · 11-21-2020, 02:09 PM

Quote:

Originally Posted by Jim34RL

Before every complains that this is a bad idea because you need the spare tire! Will in the 12 years that I have own my current truck I have never needed the spare tire. The only time that the spare tire is lowered out of the area that the tire is stored in. Is to make sure that the cable will lower the tire, this is done once a year.

Just a thought to consider...

If you do need a spare, you're looking at a 12-year-old tire.

Our 2006 Tahoe has a full-size spare. All five wheels are identical and have TPMS sensors. I got new tires last month. Before going for the tires, I lowered the spare and discovered it had a 2007 date code. So when I got the new tires, I asked my tire guy to put the best current tire/wheel on the spare lift and new tires on the other four wheels.

You may wish to do something similar.

Just an observation about something I learned in my long-ago youth. You rarely get flats on the road. You get them on the shoulder. It's that stop to take a call or check a map that does you in. I still pull off if I absolutely have to, but I avoid it whenever I can.

fred3 · 11-21-2020, 05:18 PM

I have a 60 gal tank that fits under the bed rail so I can put the tonneau cover over it when not towing. I fill the regular tank first if it has gotten into using that tank then fill the aux tank. Aux tank outlet has a 1/4 turn ball valve that then goes directly into the fill tube of reg tank. The aux tank will fill the reg tank as the contents are used. My gauge will go down then will show full again if i hit a bump or turn engine on/off. As others have said, best mod you can do for your truck.

Jim34RL · 11-21-2020, 07:53 PM

Quote:

Originally Posted by Larry-NC

Just a thought to consider...

If you do need a spare, you're looking at a 12-year-old tire.

Our 2006 Tahoe has a full-size spare. All five wheels are identical and have TPMS sensors. I got new tires last month. Before going for the tires, I lowered the spare and discovered it had a 2007 date code. So when I got the new tires, I asked my tire guy to put the best current tire/wheel on the spare lift and new tires on the other four wheels.

You may wish to do something similar.

Just an observation about something I learned in my long-ago youth. You rarely get flats on the road. You get them on the shoulder. It's that stop to take a call or check a map that does you in. I still pull off if I absolutely have to, but I avoid it whenever I can.

I have been driving since the mid-60's and I have had three flat tires on all of the vehicles that I haven driven. One of my flats tires was from crossing a picket line to go to work for Cat.

That 's why I suggested an optional fuel tank in place of a spare tire!

In fact some automakers are not providing full size tires as standard equipment. They are now optional so, if you do not order a spare tire you do not get one!

MCA01462 · 11-22-2020, 12:14 AM

This summer i installed a 69 gallon tank in the bed. I have a manual valve at he tank that i leave open and installed a motorized ball value that I can turn on from the cab. It is great being able pick where you fuel and buy at the right price. wish i did it years ago.

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

MCA01462 · 11-22-2020, 12:24 PM

Quote:

Originally Posted by kcmusa

Yes I understand the kits.
Does the aux tank complete drain?
How fast or slow is the transfer?

Mine will flow just a little faster than the rate that i use it.. I normally let the main tank get down just below 3/4 and than I let the aux tank flow...

nayther · 11-24-2020, 11:07 AM

on my old 2005 Duramax I'd throw a fuel gage code on occassion. The computer didn't know what to do when the gage doesn't move for 100's of miles. It was a nuisance.

tinkerreknit · 11-25-2020, 10:20 AM

I have an F250 and I got a code 1 time about a faulty fuel sending unit. But for whatever reason, I almost transfer fuel when I'm parked. Solves that code fault. I don't have a tonneau cover, but it's a little surprising that my auxiliary tank is an inch higher than the bed.

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