Hey guys,
I just order a 2020 Crew Cab Xl diesel short box truck . I want to extend the range between fillups and benefit from filtering the fuel before it enters the truck tank, I plan on getting a Rds 40 gallon tank that will fit under my Weathergaurd saddle tool box. Here's where is gets fuzzy for me, how to get the fuel from the slip tank through a Donaldson 3 micron filter water separator to the truck tank. My goal is to never pump fuel directly in the OEM fill and keep my truck OEM tank as clean as possible. I could use a Walbro 255 L/hr inline, Carter 380 or should I lean more towards a 8 gpm transfer pump like a fill rite or GDI. Rds has a T that goes in the OEM filler neck but I don't know what size threads it has or how much fuel it could flow.
thanks!
Jake p

 

So you are never going to fill your truck through the factory fill pipe and only fill the transfer tank then pump into the main tank through filters?

 

That's the plan, that way all the fuel gets filtered through a 3 micron Donaldson water separator. They are way cheaper than the factory filters too.

 

been doing it for years. I do occasionally put fuel directly into the trucks main tank if I need to go 1000 miles, but normal everyday use all fuel goes in the aux tank and gravity fills the main tank through a Bosch filter froma VW. The VW filters are cheap and very effective.

 

Don't overthink it too much. I keep about 70 gallons in my aux tank on the 02 and then cycle it through every 4-6 months and fill it up again. I just fill the OEM tank as needed and keep the extra for trips/emergency. I don't use any type of water separator or additional filter and I have never had an issue with water or contaminants and I have run this system for 16 years or so. I run a simply Holley fuel pump mounted inside the bed with a switch on the dash.

 

Sounds like you are exactly where I was in my thinking a few months ago. I ended up going with a 45 Gallon KSH toolbox/fuel tank combo. I didn't want to deal with a gravity fed tank, because of the leaks that have been discussed. The KSH tank is designed to have fuel pulled out of the top, and fuel level is acquired through a marine fuel sending unit. I ordered a 72 GPH Carter fuel pump, as it fit perfectly inline and is safe to run off of my #1 Aux upfitter switch. This pump works best pulling fuel, not pushing as I discovered. I have since rerouted the fuel lines to go through both of those filters before reaching the pump now. I ordered a 30 micron fuel filter/water separator. I wanted to go to a smaller micron filter, but the flow rate is reaaally low through that small of a fuel filter/water separator. Plus, any water that is picked up will be deposited into the clear fuel bowl. I could have ordered a dimensionally larger filter with better flow, but I wanted it to completely fit inside of the tool box. I have it mounted at the top of the tool box, and there is just enough room to be able to drain the fuel bowl if need be. It takes around 5 minutes to fill a 1/4 tank, so around 20 minutes to fill if I'm sitting on E. I ran the fuel gauge into my center console. I used an aux tank install kit from ATTA in Fort Worth. Their kit ties into the vent line of your truck, and has a return line off of it. So if I'm filling my main tank and I forget to turn off the pump...the overflow is simply routed back to the Aux Tank. I did experience a leak from the top of my main tank due to siphoning, but I immediately remedied it using the anti-siphon valve that was included with the Carter pump.

 

This is exactly the information I needed thank you! Do you think there would be any issues venting the main to the transfer tank on a 2020?

 

I don't think there were any changes on the fuel system from my '15 to the '20 as long as it's diesel. My main tank just vents back to itself. It ties back into the main filler neck, about an inch down and to the left. The main issue we face is expansion, which is why they say to never completely top off the aux tank.

 

Would this cause any issues with the emissions/vacuum system?

 

That's only on gas trucks.

 

Ahh gotcha thank you

 

No problem! I learned that our diesel trucks didn't have the charcoal canister/EVAP equipment when I was researching for the install of my tank. Come back and share your setup to help out others once you get it set up! You may also try checking Craigslist for a used tank. There were a bunch available when I was searching. I picked mine up on OfferUp for around $300 within 20 miles of my house. You never know what's out there till you look!

 

Will do ! Now I need to pick a pump out and get it on order, I'm between a Walbro GL362, Carter 4600 or a Bosch 044. Any advice there? My fuel filter is rated a 100 gph so I'd like to be around there

 

I do something similar. I modified an aluminum tank and added a GPI pump on it that goes through a hydrosorb. I only fill my main tank from this pump. It all fits nicely under my tonneau cover. I still maintain the factory filters though.

 

I would first figure out where you’re going to mount the filters and pump. Space can be kind of limited as you will discover. It sounds like you’re going to have a dimensionally large sized filter. I would start with that first. I have seen posts where someone mounted a large filter down on the frame rail. It hung too low for my application though. My truck sees a lot of oilfield lease roads, and I didn’t want to take a chance on something getting kicked up and damaging it. I would also be thinking about how you want to wire up your pump. If you want to use your factory up fitter switches, assuming you have those...there are limitations to what you can hook up there. I think I paid $62 for my Carter pump shipped and it came with the anti-siphon valve. Don’t forget to install one of those btw! It installs inline, and I have it after my pump.