I just purchased a 2007 2500 with the 5.7.

I'm starting to go through it to figure out all the issues. It appears that someone used a compression fitting to repair the brake line that runs front to back. That's a no-no in my state, at least that's what I've been lead to believe and regardless I don't want a compression fitting on there. I think I'm going to plan on replacing the entire line instead of trying to splice in a flared union. Or maybe I'll do a union just to get me through the winter. It's too cold and snowy for me to spend that kind of time outside right now.

Anyway, I'm still waiting for my FSM to arrive and wanted to get started with my research and planning. Can someone tell me what diameter the line is and what type of flare Dodge uses? My last experience with rusty brake lines was on a 94 Cadillac with bubble flares. I really hope they are just double and not bubble. Also, what do people think about NiCop vs. coated steel? I tried NiCop with the bubble flares and could not get a proper flare with it. I was able to get a decent bubble flare with coated steel though. Thanks.

 

Im pretty sure it will be 5/16 line. I would double flare it and put in a union until the warmer weather.
The nicop line seems to be the line of choice nowadays for repair due to the easier bendability. i have not had any issues with flaring it.
The rest of the factory connections will be bubble flare.