Auxilary Fuel Tank

[abrooks]

Has anyone added or replaced a fuel tank on a Duramax? If so what do you recommend?

[dakotakid]

I replaced the oem tank with a transfer flow 45 gal. tank on my 02 and 04. I thought about going with an add-on in the box, but didn't want to give up the space. The 45 gal tank is definitely an improvement - gets me down the road a lot further...

Pat

[jjackson]

abrooks, There is a lot of info on TDP, you might want to do a search. Also, you might want to check out RSD Manufacturing. I installed their 41 gallon combo tank. I've had it for about 2 years and like it. One thing I wanted was a unit that did not stick up above my bed rails. Its a diamond tread aluminum unit. If the # is still the same, it is 860-584-6898. I have an email of: bholden@rsdaluminum.com

John

[Mile Hi Guy]

I just purchased a 45 gal tank for tranfer-flow as well on my 04 LLY. I like the extra capacity but when it is on E I still have 10 gallons in the tank

My concern is if I will have extra air in the fuel system if I use atleast 5 to 6 gallons of this. The DIC is pretty usefull for keeping track of the fuel used and left.

Any one have thoughts on this one?

Thanks

[More Power]

We're supposed to have a couple of Transfer Flow tanks to look at next month during the Rendezvous/Pull-Off on July 16-17 here in western Montana. Would be a good time to examine the tanks and ask questions about installation.

MP

[dakotakid]

With my transfer flow tank, my low fuel light comes on with 12 gallons left on my 2002. I have used 40 of the 45 on several occasions, and never had any problems with my 02. On the 04, my low fuel light comes on at the same time - but I haven't had it any lower than 10 gallons left yet. I will try and run it a little lower this time out!

Pat

[abrooks]

Really appreciate the replys but was wondering if I was going to tow a fifth wheel wouldn't be better to have an auxilary tank somewhere else than putting it in the bed? I don't know. I am just asking.

[bigbud450]

abrooks,
I built a low profile aux tank which is mounted across the back of the bed, next to the tail gate. The front quick attaches to 5th wheel frame rails and the rear by two bolts in back side corner panel. At 8" high my 5th wheel trailer pin clears top easily when hitching. My reason to locate there was I wanted to keep bed in front of the hitch free for storage, and I wanted more weight distributed to the truck's rear, and that area was wasted with a 5th wheel hitch. Most of the time I leave the tank in, full of fuel, as it gives a better ride and the low profile still allows me to haul lengthy items. I installed a switch in the cigarette lighter which starts a electric fuel pump pumping fuel into the fill neck just below the front left corner bed. I have a vent line which runs back so the system remains closed with the trucks fuel system. The 40 gals tank + trucks 26 gal (short box) allows many miles before seeing the pumps. It cost me about $110 for all materials. I can post a pic if desired.

[abrooks]

Bigbud450,

Thanks for the info. I was concerned that if I was in an accident with the fifth wheel hitched that I might increase the chances of a fire hazard but further research seems to bunk that theory.

[dakotakid]

abrooks

The transfer flow tank that I used goes where the factory tank is located. You remove the factory tank and put the transfer flow tank in its place. It hangs a little lower on the frame, but I will gladly sacrifice that clearance for an extra 20 gallons of fuel!! Plus - the bed is still free to haul whatever you wish...

Pat

[Scott Duprey]

bigbud450,

Pictures of your project would be greatly apprecaited.

Any desire to make a second tank and setup and sell it? Just asking.

[hd90rider]

I have a 115 gal tank installed in the bed. It has a solenoid,with a switch in the cab that switches between the 2 tanks. I deliver Rvs all year & really need the big tank to take advantage of lower fuel in different states. Is especially nice so you dont have to fuel in Ca. I also installed a filter on that tank, so the fuel goes through 2 filters,befor reaching the motor. This tank is DOT approved. Installed it was around $950, including the solenoid & switch.

[kcd]

bigbud450
Any chance of getting a look at your setup pictures? Looking at doing the same thing as you have.....
Many thanks,
kcd

[bigbud450]

You can find the tank pics here: http://www.picturetrail.com/gallery/view?p=999&gid=4598413&uid=2339453&members=1

The tank is 9 x 20 x 59 inches of I believe 14 or 12 gal metal from one 4 x 8 ft sheet. I welded two internal baffles and a 2 in filler on top. I tapped into the 2in fuel filler line under front truck bed drivers side with 2in gal exhaust which had two welded fittings for the two fuel lines. Any welding or machine shop or willing buddy could fabricate the tank. If I did this again I would have had the steel supplier bend the top and two long sides in U shape with a metal break. Less edges to weld and more of a finished look. I have clear fuel filter in line with the electric pump to see condition of fuel and any water present. So far it has worked "with out a hitch" except the one in front of it ;) Do like the weight of the extra fuel behind the back axle,
Let me know any changes you would make.

[Idle_Chatter]

I've got an American Tank 43 gal aux tank in the front of my bed. I'm pretty sure that hd90rider got his from American, too. It's only 19" tall (under rail) and 11" deep. Came complete with all fittings, wiring harness, bolts, etc. It's plumbed into the system with a 6-way switching valve on the frame rail and one toggle switch in the cab. You throw the switch and fuel is drawn from the selected tank, recircs to the selected tank through the factory cooler and the sender in the selected tank reads on the factory gauge. Been using it for 30 months and 75,000 miles without a hitch.
www.auxtank.com (http://www.auxtank.com)
Photos in my PICS link below.

[bigbud450]

scott,
Appreciate you asking about building a seconded tank. This is my busy time of the year with major projects in the works. As said in previous post check with local welder. They can spit one out in a couple of hours, and save you freight charges.