I put an auxiliary fuel tank in the bed and plumbed it into the factory tank.

 

Did you plumb the line into the sending unit hat? I assume you wired up a pump to a simple switch in the cab?

 

No. I just tapped into the factory filler neck. I then rigged up a simple switch in the cab for a fuel pump. I added a couple grounding straps for the auxiliary tank. It wasn’t a very difficult project.

I also have a fuel gauge for the aux tank.

I’ll try and grab you a picture of everything in the morning.

 

This is my tank. Forgive the bad photo but I’ve got all my camping junk in the bed too.

You’ll see there are 3 lines:
One goes to the fuel pump
One is a vent
One is a return line

The fuel pump is a Carter brand. It’s overkill for a transfer pump so you could easily get away with something smaller. The fuel filter is from a 04-05 Colorado. I simply drilled 3 holes in the bed for the hoses to run through. If your wanting something pretty you’re not going to like my method. Function over form.

I used a barbed fitting that I added into the filler neck. I just cut approximately 6” out of the factory filler neck and used hose to add it in.

I then ran a switch into the cab along with the wires for the fuel gauge. I used a reed style stainless steel sending unit inside the tank. They are commonly used in marine applications.

I bolted the tank straight through the bed and put a grounding strap on two of the bolts and attached them to the truck frame.

The system has worked well for nearly 80k miles.

 

@WV NATIVE thanks for the pics. This helps a lot. I’m not sure how I want to run mine yet but I’m def mounting under the bed as the bed is used for the dogs and a bit of gear. I might make an access hole in the bed but I would love to add a 2nd gas door in the bed side but not sure I need it to be that pretty.