gprguy
Well-Known Member
Step 3 - Fuel Lines
Here's a quick overview of the before/after fuel line configuration.
Before, you have two hard lines going from the rear tank forward, underneath the crossmember and they connect to hard lines right behind the cab, same area that the brakes have a junction block. The larger diameter line is the fuel supply, the smaller one is the fuel return (fuel vapor in Ram's vernacular).
We'll be removing those two lines and instead installing two shorter lines that go from the midship tank location up to the hard lines. We'll then install a third line (which is actually two pieces) that goes from the rear tank fuel supply port to the midship tank auxiliary port. The old fuel vapor port on the rear tank gets capped off and not used.
The auxiliary port is normally used to draw fuel out for an onboard generator, welder, etc, anything diesel powered. But it's really just a port into the tank, so in dual tank setups that's where the rear fuel pump (now re-purposed as a transfer pump) can dump fuel into from the rear tank. The BCM will monitor the fuel level in the midship tank and when it gets low enough activate the rear fuel pump to transfer fuel into it until it's full enough. The engine runs 100% off the midship tank.
Here's a comparison picture for length of the old fuel lines vs. the new ones.
These lines will be full of fuel of course, so be prepared to make a mess. I drained the fuel out of the under cab fuel filter (there is a small petcock on the side) which helped some, but there will still be some left especially in the return line.
Be delicate with the fuel line quick connectors. There are a couple different styles, some with safety clips and some without, but be patient as they are all plastic.
I'd start by disconnecting both lines at the rear tank (leave the breather line that goes to the rollover valve alone, that stays as-is) and rotating them upwards 90 degrees so they don't leak fuel. They have a separate section on the end so you can spin them upwards if you remove the lines from the clips. Then disconnect the lines at the frame connections behind the cab - these lines have little blue safety clips on them that have to come off first, then you can fight with disconnecting the actual clips. Drain the remaining fuel from the lines into a catch pan. Below you can see the fuel lines disconnected (please excuse all the other wires and air lines here, I am in the middle of my air suspension install).
Once you have them reasonably empty of fuel you can disconnect the two small extensions off the rear of the lines - best to have those out of the way. Next you need to get them removed from the truck. I was able to remove them without cutting them, but it was a struggle to get them past the crossmember where they go underneath. It took a bunch of persuading and some light bending, but what worked for me was to work them backwards enough to clear the front crossmember, then pull the front down and take them forward. Sliding them past the shock was the trickiest bit.
Once they are removed, install the new front lines (05146908AA fuel supply, 05146916AA fuel vapor) making sure you get the right line in the right place. The supply (larger line) goes on top. These are much easier to install due to their short length. Once they are in you can line up the brake and fuel lines in each clip and close them up.
Next install the rear transfer line. This comes in two pieces - put the main hardline (68193570AA) in first. It goes through the crossmember and will fit in the upper portion of the frame clips. You can close those clips up when you are satisfied with the routing. Lastly install the rear section of the transfer line (68193999AA), it's an L shaped piece that connects from the frame hard line to the supply (large driver's side port) on the fuel tank. It has those blue/red safety clips on both ends.
At this point the rear section of the fuel line should look like this:
And at the midship location you should have 3 fuel lines ready to connect to your new pump:
Please keep in mind if you have a 4500/5500 60" CA (or anything other than an 84" CA) the fuel line part numbers will likely be different.
If you have a 3500 60" CA I have what I think are the correct part numbers in the post below but I have no way to verify.
hdrams.com
Different years may also mean different part numbers, this was all done on a 2022 4500 84" CA truck. I am reasonably sure this will be good for any 2021-2023 4500/5500 84" CA truck but your milage may vary.
<continued...>
Here's a quick overview of the before/after fuel line configuration.
Before, you have two hard lines going from the rear tank forward, underneath the crossmember and they connect to hard lines right behind the cab, same area that the brakes have a junction block. The larger diameter line is the fuel supply, the smaller one is the fuel return (fuel vapor in Ram's vernacular).
We'll be removing those two lines and instead installing two shorter lines that go from the midship tank location up to the hard lines. We'll then install a third line (which is actually two pieces) that goes from the rear tank fuel supply port to the midship tank auxiliary port. The old fuel vapor port on the rear tank gets capped off and not used.
The auxiliary port is normally used to draw fuel out for an onboard generator, welder, etc, anything diesel powered. But it's really just a port into the tank, so in dual tank setups that's where the rear fuel pump (now re-purposed as a transfer pump) can dump fuel into from the rear tank. The BCM will monitor the fuel level in the midship tank and when it gets low enough activate the rear fuel pump to transfer fuel into it until it's full enough. The engine runs 100% off the midship tank.
Here's a comparison picture for length of the old fuel lines vs. the new ones.
These lines will be full of fuel of course, so be prepared to make a mess. I drained the fuel out of the under cab fuel filter (there is a small petcock on the side) which helped some, but there will still be some left especially in the return line.
Be delicate with the fuel line quick connectors. There are a couple different styles, some with safety clips and some without, but be patient as they are all plastic.
I'd start by disconnecting both lines at the rear tank (leave the breather line that goes to the rollover valve alone, that stays as-is) and rotating them upwards 90 degrees so they don't leak fuel. They have a separate section on the end so you can spin them upwards if you remove the lines from the clips. Then disconnect the lines at the frame connections behind the cab - these lines have little blue safety clips on them that have to come off first, then you can fight with disconnecting the actual clips. Drain the remaining fuel from the lines into a catch pan. Below you can see the fuel lines disconnected (please excuse all the other wires and air lines here, I am in the middle of my air suspension install).
Once you have them reasonably empty of fuel you can disconnect the two small extensions off the rear of the lines - best to have those out of the way. Next you need to get them removed from the truck. I was able to remove them without cutting them, but it was a struggle to get them past the crossmember where they go underneath. It took a bunch of persuading and some light bending, but what worked for me was to work them backwards enough to clear the front crossmember, then pull the front down and take them forward. Sliding them past the shock was the trickiest bit.
Once they are removed, install the new front lines (05146908AA fuel supply, 05146916AA fuel vapor) making sure you get the right line in the right place. The supply (larger line) goes on top. These are much easier to install due to their short length. Once they are in you can line up the brake and fuel lines in each clip and close them up.
Next install the rear transfer line. This comes in two pieces - put the main hardline (68193570AA) in first. It goes through the crossmember and will fit in the upper portion of the frame clips. You can close those clips up when you are satisfied with the routing. Lastly install the rear section of the transfer line (68193999AA), it's an L shaped piece that connects from the frame hard line to the supply (large driver's side port) on the fuel tank. It has those blue/red safety clips on both ends.
At this point the rear section of the fuel line should look like this:
And at the midship location you should have 3 fuel lines ready to connect to your new pump:
Please keep in mind if you have a 4500/5500 60" CA (or anything other than an 84" CA) the fuel line part numbers will likely be different.
If you have a 3500 60" CA I have what I think are the correct part numbers in the post below but I have no way to verify.
Mid ship fuel tank
Got ya, like I said the research aspect is not my thing but to have and pile of parts sitting in front of me I can put that in haha. I’m 99% sure it’s still an option to have it on mine but still not 100% 
Sent from my iPhone using Tapatalk Yep, it's an option. You've got what I've...
Sent from my iPhone using Tapatalk Yep, it's an option. You've got what I've...
hdrams.com
Different years may also mean different part numbers, this was all done on a 2022 4500 84" CA truck. I am reasonably sure this will be good for any 2021-2023 4500/5500 84" CA truck but your milage may vary.
<continued...>
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