2015 lml dual tank

Yngdmax92

Active member
Sep 26, 2013
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Food for thought for you guys. Maybe you guys can tell me If I can do this or not. This lml has a fuel pump, fuel pump relay, and fuel pump module for the dual tank set up. It keeps having problems and has been to the dealer, they keep changing sending units and transfer pump and I think I have a better idea. Is it possible for me to install a lift pump, put a t in the suction line and just draw off from both tanks. Then changes the operating system in the truck to one that does not have dual tanks and just get rid of the transfer pump and wiring all together. Has any body ever done this? It's a standard 3500 dually with a 10 foot dump bed on it. Sick of seeing this truck, sick of having these dual tank issues. What do you guys think?
 

clrussell

pro-procrastinator
Sep 23, 2013
5,906
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The problem is you would have to fill both tanks equally. Plus the returns would need split too.

better off to find the actual problem lol. It’san extremely simple system.
 

GMC_2002_Dmax

The Still Master
Food for thought for you guys. Maybe you guys can tell me If I can do this or not. This lml has a fuel pump, fuel pump relay, and fuel pump module for the dual tank set up. It keeps having problems and has been to the dealer, they keep changing sending units and transfer pump and I think I have a better idea. Is it possible for me to install a lift pump, put a t in the suction line and just draw off from both tanks. Then changes the operating system in the truck to one that does not have dual tanks and just get rid of the transfer pump and wiring all together. Has any body ever done this? It's a standard 3500 dually with a 10 foot dump bed on it. Sick of seeing this truck, sick of having these dual tank issues. What do you guys think?

Put a single tank in, and forget about the aux tank

I assume its a 23/39 combo ?
 

Yngdmax92

Active member
Sep 26, 2013
962
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28
The problem is you would have to fill both tanks equally. Plus the returns would need split too.

better off to find the actual problem lol. It’san extremely simple system.

you say its a simple system, but it keeps having the same reoccurring issues, and spitting the same codes. Keeps losing communications to the module, which then messes up the transfer pump, fuel levels on the dash. lol i have chased wires and so forth. I do not understand what is going with the unit, its intermittent and this is a dump truck that lives in upstate ny. The modules are living in salt and water every day, the gentleman relies on this truck for work everyday weather its plowing or hauling material. I am at my wits end with it!
 

Yngdmax92

Active member
Sep 26, 2013
962
44
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Put a single tank in, and forget about the aux tank

I assume its a 23/39 combo ?


i honestly think this is a 36( what ever the larger long box tank would be)/39. Its a 10 foot dump body on the truck. I am going out on a limb and looking at this tank it is pretty larger in the front. But yes. i would delete the back tank no problem.... would it be that simple of deleting the back tank and putting a different operating system in the truck?

Cause right now it has 2 sending units, a transfer pump. The 17067 diesel dual tank transfer pump and plumbing update was supposedly done to the truck but its still having the same issues.
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
3,890
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ZEPHYRHILLS, FL
You could have a single tank fuel system flashed into it, set it up to pull from 1 tank, and then put your transfer tank on a toggle switch to manually fill the main tank. Putting a T in would be a nightmare and nothing but problems. Say you went up an incline, it wouldn't take long before it either sucks air from the higher tank, or the lower tank starts running over.
 

Yngdmax92

Active member
Sep 26, 2013
962
44
28
You could have a single tank fuel system flashed into it, set it up to pull from 1 tank, and then put your transfer tank on a toggle switch to manually fill the main tank. Putting a T in would be a nightmare and nothing but problems. Say you went up an incline, it wouldn't take long before it either sucks air from the higher tank, or the lower tank starts running over.
Never thought of it that way. Good thinking!!! Thanks!