The brake hardlines are not looking so good but not leaking on my daily driver. Id like to coat them with something to slow the rust as much as possible and protect them in general. What would be good to use? Is the rubberized undercoating waterproof? What about truck bedliner coating? Just looking for some ideas to extend the life of the lines.

 

You can try all of the above, but I suggest you replace them.

 

Rust bullet.... https://www.amazon.ca/Rust-Bullet-Au.../dp/B0002P3IJ8 94

 

so i had the power steering low pressure line rust a pinhole. after a quick brake cleaner bath i put jb weld(in the tubes not the putty) on it and let it set up overnight. it stopped the leak. i have since replaced with new oem lines but the jb weld worked if you are in a pinch

 

The first thing to come to mind was Rustoleum rust reformer paint. It will stop the rust present from my understanding. At least that was the marketing when I was a child.

https://www.amazon.com/Rust-Oleum-Au...D4RW2MMDM9RXCJ

 

Wait, are you comparing a low pressure line to a brake line? No way... You know that brake systems see ~800 psi in normal conditions and more than double that under emergency stops? Also if your PS line leaks, it's a mess at best and boost failure at worst... Brake system failure is well, obvious. I know you're one of the smarter people around here so I am going to assume you are kidding with the JB Weld

 

I would also recommend to replace because you never know which push of the pedal is going to cause the break and especially if you don't know how bad they really are under the plastic cover..

this happened when I was about 3 hours away, a costly mistake that could have been prevented



ended up getting lines from the dealer which were like OE ones with the length and somewhat of correct bends

 

As mentioned best bet, [smart thing] is to replace the lines, 94