Fuwl Tanker Truck With Gravity Feed

• #1

Not sure where to ask this, but here goes. For those that have a gravity flow fuel tank do leave the valve open, or close it until the factory tank is down to say half full?

Thanks. Bob

• #4

I close mine when I am parked for any time. when driving I leave the valve open. I was having problems with the oem tank losing fuel due to heat expansion when full.

What he said.

• #5

I have a 12V soloniod hooked to an upfitter switch. I turn it on between 3/4 and full and usually leave it on when towing, I also have a manual shutoff.

• #6

Thanks for all the quick responses. Is just confirms my thoughts. I installed my tank today and then filled the factory tank and the new auxiliary tank, opened the valve. No leaks, good. But then parked in the garage, went out tonight and had diesel on the floor coming from top of factory tank not much just drips. I shut the valve and wiped the tank off, and came to the conclusion that you guys said.
As always this forum and the people on here are the greatest.
Bob

• #7

Bob, the check valve in the fitting that goes into your filler pipe needs to be in a vertical position. Your main tank will fill to that spot in the filler pipe. My guess is that even after the check valve cuts off the flow, assuming that it does, the fuel in the filler pipe may expand from warming up and start leaking out around the cap. I usually shut my aux. tank off when I'm parked. Saving as much as 30 cents a gallon when I get into another State and the convenience of not having to stop for fuel unless I want to makes it all worth it to me..Safe travels, Don

• #8

Just curious about legality of the gravity fill system. Or, at least the safety.

• #9

Just curious about legality of the gravity fill system. Or, at least the safety.

Gravity feed system is DOT legal. This has been discussed many times over. Not legal for gasoline. Literally thousands in use. There is a check valve in the vent in the event of a rollover as well as a check valve in the fill hose. I'm installing mine in its' second truck. One of the best things I've bought...Don

• #11

Yes I checked all connections, factory cap and check valve in the T. Not leaks anywhere. As has been said, and my initial thoughts, the pressure was forcing out of the factory tank overflow on the top. Just went out and checked since I closed the auxiliary valve and has stopped dripping.
Bob

• #13

Mine is open all the time and I have had no problem. I do not fill my auxiliary tank completely. Make sure when you install put the check valve in the correct position. I am very happy with mine. I like the simplicity of the system. My chevy reads the fuel correctly-Full until extra tank is empty then regular tank reading on the OEM tank. If the gravity tank is illegal then why do the manufactures keep building them? No bashing here just a simple question.

JWalker

Northeast Region Director-Retired

• #14

RDS 37 gallon tank. Gravity fed. Simple and works great. Only holds a true "32 gallons". But 32 gallons gets me another 350 miles.

• #15

My 55 gallon tank was hooked up by my Dodge dealer. Shut off valve at the tank and hooked directly into the main fuel tank, not the filler tube. My truck tank has a factory auxiliary port fitting on the tank. I keep it full at all times and never had it leak or spill over. I also have quick connects on top to fuel my ranch equipment and a portable 12 v fuel pump. I have had this tank on my last two Dodges, no issues. When traveling, I wait until the main tank is 1/4 remaining and then flip on the valve and leave it until its time to fill up. I generally get around 1400 miles off both tanks when not pulling. Pulling I can make it from my ranch to Casper Wyo without refueling...1200 miles one way. By the way this is diesel fuel..

travelin2

Pennsylvania Chapter Leaders-retired

• #17

RDS 37 gallon tank. Gravity fed. Simple and works great. Only holds a true "32 gallons". But 32 gallons gets me another 350 miles.

I have the same setup. Open the valve on reserve tank if fuel stops are far between, inconvenient, or it's cheaper to fill up down the road.

• #19

I installed a tank from attatank.com with the freedom fill system. A little more expensive but works really good and it's worry free.

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• #20

I used a selonoid only for a few years and since have added a pump and fuel filter to filter fuel thru before going to stock tank.

rodriguezrevey1974.blogspot.com

Source: https://heartlandowners.org/threads/gravity-flow-auxiliary-fuel-tank-question.49731/

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