Aux fuel tank

[Tsys100718]

I installed a Transfer Flow aux tank in my new 3500 DRW. It's only 40 gal., but that's enough for me. I plumbed it to the filler neck and added a fuel pump, normally closed solenoid and switch in the cab. I turn the pump on and watch the fuel gauge, miles to empty, etc rise accordingly. I used to have this setup in my old gasser RAM, but I had an external pump and nozzle that also worked very well. I simply used an alligator clamp under the hood to get power to the pump. It was a 10 GPM pump, so fillups were fairly fast. My new setup uses a Holley 140 GPH pump and it fills my tank in about 15 mins., if I'm sitting still. I have the 31 gal. tank.

 

[Parkerlouis13]

Did a search and found this old thread. Installed a dee zee 40 gallon transfer tank and the filler neck adapter on my 2019 Ram 6.7. I just tested tonight to see how long it would take to fill the oem tank using the valve. At first I couldn't hear fuel trickling into the oem tank so i opened the fuel fill flap and i noticed pressure would release. Fuel started trickling into the oem tank but I'm wondering if this is normal? Also, any recommendations for an inline pump to make fill ups faster while traveling? Thanks

 

[Nick]

Did a search and found this old thread. Installed a dee zee 40 gallon transfer tank and the filler neck adapter on my 2019 Ram 6.7. I just tested tonight to see how long it would take to fill the oem tank using the valve. At first I couldn't hear fuel trickling into the oem tank so i opened the fuel fill flap and i noticed pressure would release. Fuel started trickling into the oem tank but I'm wondering if this is normal? Also, any recommendations for an inline pump to make fill ups faster while traveling? Thanks

Just get a low flow electric fuel pump . Put a universal filter in front of it wire it to one of your aux switches and you should be good to go.

 

[Parkerlouis13]

Just get a low flow electric fuel pump . Put a universal filter in front of it wire it to one of your aux switches and you should be good to go.

I did a search on Amazon for pumps. They all seem to be low quality from the reviews I read. Can I add factory aux switches to my tradesman? I only have 2 toggle switches for exhaust brake and trailer

 

[Phil T]

Stick with Fill-Rite pumps. They are made for that purpose.

 

[CallMeChris]

You can ONLY do this with diesel. DOT regulation prohibit it with gasoline (too explosive!)

just a heads up. DOT does allow auxiliary gas tanks, they just can’t be plumbed in like the diesels, have to be external fill through a pump. I just had a 50 gallon transfer flow installed. Also, can’t go over 100 gallons or you have to have hazmat endorsements. I do know of people that have plumbed in gas tanks and have passed DOT inspections but it’s my understanding it’s a very gray area and safer/easier to just do the external fill route.

 

[CallMeChris]

 

[Gondul]

just a heads up. DOT does allow auxiliary gas tanks, they just can’t be plumbed in like the diesels, have to be external fill through a pump. I just had a 50 gallon transfer flow installed. Also, can’t go over 100 gallons or you have to have hazmat endorsements. I do know of people that have plumbed in gas tanks and have passed DOT inspections but it’s my understanding it’s a very gray area and safer/easier to just do the external fill route.

All I've seen mentioned is that it cannot be gravity fed and has to be "pumped" from the top, a top mounted electric pump feeding into the system would also meet the requirements.
So unless someone finally makes a larger tank for the 6.4, that's probably what I'll end up doing.

 

[AttilaTheHun]

I’m running an RDS tank gravity feed.
Its the 41 gallon short bed option for my Megacab.
It’s outstanding and holds about 36 actual gallons.


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do you have the exact model number of the tank? I'm looking for one for my short bed, but I'd like it to fit under my tonneau cover. Do you happen to have pictures? I hear RDS is good quality. Thx man!

 

[NordicNevs]

Here is what I got

RDS MFG INC 72773 Fuel Tank https://www.amazon.com/dp/B001KLJGP8/ref=cm_sw_r_cp_apip_z5q3daAFZKiIg

And the filler neck as well.

RDS has been amazing with their customer service. I had one issue where my pins were too long. Without question they said give us a measurement and we will send them. And they did.

Build quality is great for an aluminum tank and my range is fantastic.


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[AttilaTheHun]

Here is what I got

RDS MFG INC 72773 Fuel Tank https://www.amazon.com/dp/B001KLJGP8/ref=cm_sw_r_cp_apip_z5q3daAFZKiIg

And the filler neck as well.

RDS has been amazing with their customer service. I had one issue where my pins were too long. Without question they said give us a measurement and we will send them. And they did.

Build quality is great for an aluminum tank and my range is fantastic.


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Thank you. This one looks great. I need to look for one with the notch on the bottom, but that's less than 20" tall so I can fit it under the tonneau. thx for the reply, aslso: nice truck. wish I got mine in blue.

 

[NordicNevs]

Thank you. This one looks great. I need to look for one with the notch on the bottom, but that's less than 20" tall so I can fit it under the tonneau. thx for the reply, aslso: nice truck. wish I got mine in blue.

You’re very kind thank you.

Check out “The Fuel Box” they might be lower but the challenge will be that t cover. I fought the same battle and ended up just leaving the T cover off. So far I haven’t missed the cover that much but that being said if you forgo the tool box you’ll be able to get something lower. Only challenge will be filling up with the T cover there depending on the configuration.

Best of luck snd post back what you find!!!


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[AttilaTheHun]

You’re very kind thank you.

Check out “The Fuel Box” they might be lower but the challenge will be that t cover. I fought the same battle and ended up just leaving the T cover off. So far I haven’t missed the cover that much but that being said if you forgo the tool box you’ll be able to get something lower. Only challenge will be filling up with the T cover there depending on the configuration.

Best of luck snd post back what you find!!!


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well, more often than not, my T cover is rolled up when I'm pulling the 5th wheels. But when I'm in "incognito" mode (hint: RV Transport) so to speak, I like to have all my gear, 5th wheel hitch and tools under the cover from prying eyes. I don't need a toolbox on top of it, I'm going to look for a toolbox that goes by the tailgate. for now all my stuff is in totes that I ratchet down. I'd love to have that extended range, and fueling on the go. It's really annoying having to stop every 3-5 hours depending how heavy I'm pulling.

 

[ZiMoni]

Update. Installed it. No leaks and works like a champ. Thanks to all that had inputs

Did you have to add a gas cap, or do you have just the flapper?

 

[Rappr]

Did you have to add a gas cap, or do you have just the flapper?

I just left the plastic plug that came with the truck in.
I always refill via the aux tank filler port so, I never open the trucks filler port

 

[ZiMoni]

Mine didn't come with a plug. I assume without that, the fuel will overflow? Or would the ball valve in the fuel line cut off first?

 

[H3LZSN1P3R]

Mine didn't come with a plug. I assume without that, the fuel will overflow? Or would the ball valve in the fuel line cut off first?

No the fuel wont overflow you dont need a fliller cap even the *plug* some people have is just a little peice of plastic that does nothing to seal the filler neck

 

[Rappr]

Mine didn't come with a plug. I assume without that, the fuel will overflow? Or would the ball valve in the fuel line cut off first?

The cap that comes with a new truck is just a crappy dust cap...it doesn’t seal anything.

No, you do NOT need any cap on the trucks fuel port to keep the fuel from flowing out of it.

The RDS valve shuts off the fuel regardless of whether a cap is on or off the trucks fuel port.

 

[SMK Shoe]

I've had the RDS 45 gallon on for a few months now and love it. with a 50 gallon OEM tank, it gives me a comfortable 700 mile range. I run my tank down to about 1/2 and then flip the valve. As long as I am getting about 8 miles to the gallon, the gravity feed keeps up and slowly increases DTE. worst part about the aux tank it filling it up along with OEM tank. $$$$$ ouch

 

[Rappr]

I've had the RDS 45 gallon on for a few months now and love it. with a 50 gallon OEM tank, it gives me a comfortable 700 mile range. I run my tank down to about 1/2 and then flip the valve. As long as I am getting about 8 miles to the gallon, the gravity feed keeps up and slowly increases DTE. worst part about the aux tank it filling it up along with OEM tank. $$$$$ ouch

I have a 91 gallon tank! It costs a kidney to fill