waam

question is, if I have a aux. fuel tank in my truck box and use a gravity type feed system to let the fuel flow into my under the bed present tank, how does the air get out of the main tank. I was told we have a sealed up fuel system. I will have an air vent on my aux tank, so the fuel can flow out of it by opening a valve. Some people have tied their aux. tank drain line into their main tank fill tube, which I think is alright. But how does the air get out of the main tank as the new fuel goes in? My fuel cap is sealed I think. Do I need two lines from my aux. tank? Maybe someone can be of help in this area. <br> Thanks<br> waam Holland, Mich<br> 40% at eight PM

DPG

waam:<br>I think that air can get out of the tank the same way it gets in as fuel is pumped out. There is a vent on top of the tank. My buddy's 200l.5 has a gravity feed aux tank with just one line and it works fine. Hope that this helps. <br><br>DeWain

FiverBob

Waam,<br>Mine just &quot;gurgles&quot;. Air bubbles are coming up into the aux tank as fuel is going down into the main. This relieves the extra air from the main tank. It takes a while for 15 gallons to flow from the aux to the main. I just turn on the valve and drive. When I have what I want, I turn off the valve the next time I stop. Maybe not as convenient as the pump or the diverter valve, but a whale of a lot cheaper and fool proof. Not much to go wrong with one non-electrical moving part. 8)

Jim O

Waam The factory tank has a one way check valve in the cap that allows air to enter the tank. I have and aux tank that is connected to the filler pipe of the factory tank.I have a valve that I shut of only to service the filter between the two tanks.The rest of the time I fill the factory tank until it is full then I fill the auxillery tank until it is full. When the auxillery tank is empty the guage on the factory tank will start to go down. When the light comes on for fuel level (if I have enough money) I go and fill them both up. I asked the Cummins Dealer if there was any danger of a bad injector allowing fuel to hydraulic a cylinder and he said no chance with the new fuel system. This is not my idea but I know several people that run this system on Dodge and Ford one fellow said that if you completly fill the tank on a Duremax that it will turn the check engine light on, but I don't know this for sure. My Aux tank is 37 US gal. The fuel filler pipe is aluminum so I drilled an 11/32 hole and tapped it out to 1/8 npt. and screwed in a fitting. It has been installed for about 10000 miles now with out any problems.<br>Jim O<br>

flet top

WHAT TYPE OF FUEL FILTER DOYOU USE AO THE AUXILIARY FUEL TANK.

spots

[quote author=flet top link=board=7;threadid=13861;start=0#130432 date=1051015335]<br>WHAT TYPE OF FUEL FILTER DOYOU USE AO THE AUXILIARY FUEL TANK. <br>[/quote]<br><br>Yikes ya don't hafta YELL!!! Me da*n ears are bleedin.....

FiverBob

[quote author=spots link=board=7;threadid=13861;start=0#130611 date=1051045354]<br>[quote author=flet top link=board=7;threadid=13861;start=0#130432 date=1051015335]<br>WHAT TYPE OF FUEL FILTER DOYOU USE AO THE AUXILIARY FUEL TANK. <br>[/quote]<br><br>Yikes ya don't hafta YELL!!! Me da*n ears are bleedin.....<br>[/quote]<br><br>Now, be nice, Spots. Flet Top is a noobie. Be sweet and don't chase him away.<br><br>Flet Top - - you need to turn your &quot;caps lock&quot; key off. When you type all cap letters it means you are mad and yelling at everyone. We know you are not doing that - - right? or are you? <br><br>TurningHearingAidBackUpBob

flet top

Thanks Jim.o for emailing the answer to my queston that i asked .i have a filter on the way. Fiver bob thanks for your reply , if you dont know you dont know. i am not mad i do not get mad . i do not make fun of people that make mistakes. i am hand cap. so if you do , what goes around comes around. thanks..

spots

[quote author=flet top link=board=7;threadid=13861;start=0#130725 date=1051059414]<br>Thanks Jim.o for emailing the answer to my queston that i asked .i have a filter on the way. Fiver bob thanks for your reply , if you dont know you dont know. i am not mad i do not get mad . i do not make fun of people that make mistakes. i am hand cap. so if you do , what goes around comes around. thanks.. <br>[/quote]<br><br>Welcome to the board, flet top. Much information here, sometimes you just gotta do a search and it will come up, like net etiquette for example, and not typing in caps. Proof reading for spelling is also helpful so we get the jist of what you are trying to ask. Hope you enjoy your truck

Bradtothebone

I too have an aux tank, and according to Jim O's spec I rigged her up the same way.....Works a-ok so far....<br><br>Thanks Jim!!!<br>

moss2904

I have a question. Is there some reason to tap into the metal filler neck instead of putting a &quot;t&quot; fitting in the overfill hose next to the metal filler neck?<br> Randy

GrandpasRam

I was thinking the same thing Randy; I am leery of drilling a hole in the aluminum neck and getting aluminum shavings in my fuel tank.

Jim O

Actualy that is what I did. I removed the filler neck from the truck and drilled into the overflow tube with a 11/32 drill ( that is the tap drill size for a 1/8 npt tap. I then installed a 1/8npt to3/8 hose barb. Then after cleaning the assembly I installed it back on the truck.<br>Jim O

moss2904

I understand the filler neck can be removed , drilled and cleaned out. <br> Just wondering why you would do that instead of simply putting a t in the rubber overflow hose? Not trying to say one way is better or not, just wondering is there some reason other than personal preference to drill the filler neck instead of using a t fitting on the overflow hose? <br> The reason I ask is after a visiting a couple of auto parts stores I decided it was simpler and faster to t into the overflow hose. After reading of so many tapping into the filler neck I was curious. I would hate to have the EPA, DOT or somebody else like that explain the difference while on the side of the road. The t method seems to work just fine.<br> Randy

Jim O

I do not see anything wrong with installing a tee like you said. I had a 1/8npt to 3/8 hose barb and that is why I went that way.<br>Jim O