Fuel tank mod for more fuel

[duckmans83]

Hope this is in the right place.

So, on my f250 7.3 the tank is the same as the gas version. I did a harpoon mod which let's you fill the tank up more. I guess this is ok because diesel doesn't expand like a gasser.

Anyone heard of doing this on a duramax? I have an 05 crew cab long wheelbase dully.

Sent from my SM-G900V using Tapatalk

 

[hondarider552]

It's a 34 gallon tank, you won't fit more than 34 gallons...

 

[TheBac]

Aux tank in bed or TitanTank in place of the stocker.

 

[2007 dmax]

And yes diesel does expand

 

[duckmans83]

Thanks guys. I fit about 5 extra gal in the ford with the mod.

Sent from my SM-G900V using Tapatalk

 

[Chevy1925]

You might want to explain said mod

 

[N2BRK]

I googled it. Pretty common ferd mod. Looks like they have a lot of trouble with foaming and it takes forever to try to fill the tank. I’ve never had a problem in my dmax filling it up to the neck in short order.

 

[2004LB7]

I've fit 36 gallons in my stock tank.

I think the mod is extra vent tubes routed up high. This is supposed to let out the air better so it doesn't come back up the filler tube so it reduces foaming

 

[THEFERMANATOR]

I believe it is basically moving /adding a tank vent to the filler from the top of the tank essentially eliminating any air/expansion room in the top of the tank.

 

[duckmans83]

So you know how the gas pump does the auto shutoff then the fuel slowly goes back down in the tank, then you can add more. That's because after the filler neck reaches the tank, it protrudes into the tank a few inches. On the ford I dropped the tank while replacing the pickup and reached in there and cut the tube off with some pvc cutters.

I guess you can sit there for 5 extra min putting fuel in till it reaches the top but with this mod it's alot faster.

After the duramax clicks the first time, I think I was able to get 1 more gal in it.

Sent from my SM-G900V using Tapatalk

 

[DAVe3283]

Man you guys need some perspective

My Suburban has the stock dual tank setup, and the rear tank is above the spare tire, and is only about 6" thick. The fuel drops in about 2" down from the top, and the vents are tiny (because it was designed for gasoline).

From the first time it clicks off, I can put in 4-6 gallons. Depending on how much the pump foams, that can take me anywhere from 5 to 10+ minutes.

By comparison, the stock Duramax truck tank fills like a dream. Let it click once, wait 30 seconds, and it'll put in the last 1/2 gallon or so, and done. Maybe I could squeeze in another 1/2 gallon, but it fills so consistently it's not worth it to me.

Sent from my Cat S60 using Tapatalk

 

[Dozerboy]

You’re not going to get more in a gallon in our tanks GMs fill pretty well. If you fill up that full and let it sit you’re asking for trouble. Diesel does expand. I can’t count the number of times I’ve seen diesel fuel spill out of our equipment because is it it was filled all the way up and then sat in the sun. I’m not talking about a little bit either half a gallon on a 50 gallon tank.

I wouldn’t top off the gas either. When I first got my 2008 Chevy 6.0L gasser I would top it off. It didn’t take long for the Vapor vent solenoid to go bad. Maybe it was a coincidence, but I’ve heard if you top off your tank fuel gets in there and it ruins the solenoid.


Sent from my iPad using Tapatalk

 

[duckmans83]

On the ford it still had air in the tank when doing this. I would do this then drive 2 miles to my house and check and couldn't see any fuel in the neck.

So, what's the cheapest tank to put in the bed? Can't spend $1,600 or so on a titan.

Sent from my SM-G900V using Tapatalk

 

[duramax on fire]

On the ford it still had air in the tank when doing this. I would do this then drive 2 miles to my house and check and couldn't see any fuel in the neck.

So, what's the cheapest tank to put in the bed? Can't spend $1,600 or so on a titan.

Sent from my SM-G900V using Tapatalk

Probably a 55 gallon drum or two strapped down lol

 

[duckmans83]

Haha, that's a little too cheap. Was looking at some L tanks so I can keep my tool box. I really only tow with my truck and is a pain to get fuel with a 35 ft bumper pull.

Sent from my SM-G900V using Tapatalk

 

[Dozerboy]

I won’t buy anything used unless it’s aluminum or you can look inside it real well make sure it ain’t full of rust. Pretty sure I’ve seen 60gal in bed tanks starting around $700.

L tanks are a pretty big your looking at 100 gallons that’s almost 800lbs in your bed on top of your RV. Plus with a short bed you would have no bad space left.


Sent from my iPad using Tapatalk

 

[duckmans83]

Gotcha. I have alot better things to buy before I get a tank. Thanks for all the help!

Sent from my SM-G900V using Tapatalk

 

[gmduramax]

You’re not going to get more in a gallon in our tanks GMs fill pretty well. If you fill up that full and let it sit you’re asking for trouble. Diesel does expand. I can’t count the number of times I’ve seen diesel fuel spill out of our equipment because is it it was filled all the way up and then sat in the sun. I’m not talking about a little bit either half a gallon on a 50 gallon tank.

I wouldn’t top off the gas either. When I first got my 2008 Chevy 6.0L gasser I would top it off. It didn’t take long for the Vapor vent solenoid to go bad. Maybe it was a coincidence, but I’ve heard if you top off your tank fuel gets in there and it ruins the solenoid.


Sent from my iPad using Tapatalk

The tank isn’t in the sun on our trucks. I consistently fill all the way to the cap when I’m doing mileage testing, never lost a drop. Now on a gas vehicle you never top off the tank, gas can go into the evap system and cause problems.

 

[Dozerboy]

Good point about the sun. I’ve never lost drop out of my tank filled all the way, but I’ve never parked it right away either.


Sent from my iPhone using Tapatalk

 

[Chevy1925]

if you find a decently cheap bed toolbox/aux tank, please post back. im in the hunt for one as well. I may wind up just building one to go inside my current tool box