Auxiliary Fuel Tank...another question

[jjackson]

I know this has been discussed previously, but I am new, and have read where many of you have added "across the bed" auxiliary tanks.

Fredwe..I recall seeing a post from you sometime back where you tapped into the filler neck to transfer, but I don't recall if you are using "gravity" feed w/a manual on/off valve, or if you are utilizing a pump to transfer it.? I have a 41 gallon combo tank, and would like to initially try a very simple manually controlled "gravity" approach into the OEM filler neck. Has anyone successfully tried this approach..?

Thanks in advance...John

[Paintdude]

John, Gravity feed is doable but not recommended,because if you have a leak or accident the fuel can leak out and cost you BIG bucks for clean up..I use a Carter fuel pump mounted on my frame with a switch in the truck to run it..I also have a old style 84 chevy dual tank valve for a shut off wired to a switch in the cab..

I brazed a 3/8 nipple into my fuel neck to feed the OEM tank..I got the nipple off of an old fuel filter..

The tank I have feeds from the top, not a fitting in the bottom of the tank..

[Ade]

Paintdude,

[Ade]

Paintdude, How fast does your pump transfer? I don't recall what brand mine is but it sure seems slow. Just remembered I bought it at NAPA. I have 3/8 line and it pumps about 6 gal in 5 min.

[Applecore]

I had a fabricator make me an aux. fuel tank . It holds about 35 gal. I also got the new fuel neck from "Transfer flow". The fabricator guy got a 12v "selinoid valve" -connected a 3/8" flexible fuel hose from the bottom of the aux tank to the valve which is mounted on the back side of the cab just under the left front of the pickup box . The outlet side of the valve is tapped into the filler neck. We hooked a push-pull switch to power, and then to the valve. The switch is located on the dash. I had an empty spot below the cargo light switch. When the fuel gauge shows 1/4 or so, I pull the switch. The only bad thing is the fuel guage doesn't respond as fast as the fuel runs in. This is normal at least in my 2001 DMax. I didn't realize this until one time I left the truck run while filling the regular tank at a fuel stop. The guage doesn't go up as the fuel runs in. Turn the truck off, turn switch back on again and the guage will show full. Not easy to do while running down the road. You might experiment while sitting in the driveway, time how long it takes to fill the main tank by turning the switch of and then on once in a while. I have the switch wired so that if the ignition switch is off. the valve will not work. Works for me!

[Flyboy]

JJ Max:
I have a 45 gallon across the bed tank that is gravity fed to the main tank. I brazed two fittings to the filler neck, one for fuel and one for vent. I have a manual valve at the tank to shut it off. Simple and works good. The only problem is the filler neck is higher than the bottom of the tank and I can't get the last four gallons out of the aux tank. I would recomend a fitting in the top of the truck's tank to correct this. Hope this helps. I have been told that this setup is not legal, but what is.

[Paintdude]

I got a Carter 2.5 gal per minute pump..It sounds like you have a bad pump or maybe your aux tank isnt vented..

The fuel guage thing isnt a problem to me, I just fill when driving down the road at 1/4 and shut it off at or above 3/4..Then when it is refuel time, I fill both tanks..It isnt a exact sience but, it sure beats the heck out of a 26 gallon stocker..

The steering bearing fix and a aux tank are the 2 best things a guy can do to these trucks..IMO

[ 01-09-2003: Message edited by: Paintdude ]</p>

[poorloser]

I saw on a RV Forum where someone used the tank in the bed as a DIRTY tank (where all new fuel is pumped) and stock fuel tank as CLEAN tank (only filtered fuel). They put a fuel pump outside the DIRTY tank and two filters (1 suction 1 pressure) and pump fuel from the DIRTY tank to the CLEAN tank. I think they tee into the breather hose with 2 hoses 1 is hooked to pressure filter to the tee the other goes from the tee back to the DIRTY tank. When pump is started fuel goes down the hose from the pressure filter to the tee and on down the stock breather hose into the CLEAN tank. When fuel rises in the CLEAN tank to the breather air cannot escape and this forces the fuel up the new breather hose from the tee and back into the DIRTY tank so there is no chance of fuel spilling if pump is forgotten. Also changed vented fuel cap to nonvented cap.
I think this was done on a F**D. Has anyone done anything like this on a DMAX? Really sounds good to triple filter.

[ccds]

I have a 45 usgal combination aluminum tool box and fuel tank tied into my Transfer Flow filler neck. The transfer is controlled from the inside of the truck using a duel tank electric valve and a carter fuel pump. I also have a small electronic timer in line with a momentary switch that starts the process. It only pumps about 25 litres at a time and then automatically shuts off. This saves me from forgetting its on and loosing fuel on the ground. My system is very similar to paintdude's but mine feeds from the bottom. Like paintdude said this is one of the best upgrades, once you have installed and used this set up you will be lost without it.

I will try and take some pic's this weekend and post them.

smile.gif

[ 01-10-2003: Message edited by: ccds ]</p>

[walkerkd]

I run a 110 gallon tank in my bed. l-shape i have it gravity fed only problem is that im stuck with about 15 gallons at the bottom. im looking into adding a pump or 12v valve.

[jjackson]

Thanks to everyone for their responses/input regarding the auxiliary tank/fuel transfer. I just actually picked the 41 gallon combo up today, so will hope to mount it this weekend and then decide what approach to take.

John

[imported_]

I've got a 50 gallon tool box tank combo hooked
about the same.Only probem I had was a fuel vent.
When pumping fuel from the bed tank to the truck
tank pressure would build up in the truck tank.
A vented cap won't solve this problem because
they are only vented in,(not out).I finally
drilled a couple small holes beside the check
valve so it could vent.This worked good for
the transfer,but the bed tank was sucking in,
the vented cap wouldn't allow enough air through
to keep up.I tried the same hole trick,but fuel
comes out of the tank,I've tried a copper tube
bent into a pig tail for a vent,but it still
forces fuel out.Haven't got that part figured
out yet.

[Diesel Freak]

Run a seperate hose between the vents of each tank, one will be sucking air as fuel transfers out, the other will be expelling air as the fuel transfers in, the two will equalize each other.

[ccds]

I used a vent valve from a Kennworth fuel system. I drilled and tapped the fuel cap and it works great. It lets air in and out but has a built in check valve to seal shut if in an accident so there would be no fuel spillage. My fill neck is in a weather protected enclosure.

I will take pic's tomorrow and put up.

smile.gif

[Paintdude]

I just vent my aux tank out the top and run a hose down under ther truck..I have never had any problem with the filing proccess...

I wonder if the tranfer pump you have might be just to high of volume and pressure(a Fuel Injection type pump)..The one I bought was the lowest pressure and volume they had (Carb type)..

[ccds]

If this will help I have posted pic's of the combo tool box & fuel tank and the set up.

Look in the pic's under aux. fuel tank.

smile.gif

[ 01-11-2003: Message edited by: ccds ]</p>