Rusted brake hard line/brake hose connections: Show me your tricks

Otis, my 97 XJ, flunked Virginia safety this month due to brakes at all four corners that were making incomplete contact with the rotors.

I was tired of them anyway, and replaced everything (including the calipers) with stock-ish parts. Very nice outcome; the car now stops like a car should stop.

I bought replacement brake hoses too. The car's old enough to vote, after all. The originals were good enough to re-use but I will be keeping an eye on them.

I'm sure you can imagine, the nuts on the ends of the hard lines, and the threads into the hose fittings, are rusted like an abandoned steam tractor.

Other than PB Blaster overnight-soaks and flare nut wrenches, what are people's tricks for getting these things separated without needing new fittings for the hard lines?

A) Pop the rubber lines out of their brackets, leave the metal lines and nuts stationary and spin the rubber hoses off.

B) Very slowly and carefully work the nut back and forth after applying copious amounts of penetrating fluid.

C) Replace the metal lines. This is coming sooner or later so don't fight it too long.

yep. new lines. They arent THAT bad to replace, and will probably need attention soon anyway. Might as well get it all done at once.

Are you trying to get the rubber hose off of the hard line? Cut it and use a real socket wrench.

Use fire to make the tube nut glow orange. This WILL make the rubber hose explode out of the fitting so don't stand too close.

Or cut the line and replace it all.

Knurled wrote: Use fire to make the tube nut glow orange. This WILL make the rubber hose explode out of the fitting so don't stand too close. Or cut the line and replace it all.

I second the fire part... But does not have to be red hot. One of those small torches that you sweat copper pipes with have worked very well for me.

Resurrecting this old thread since it's directly on-topic.  I've got a Mazda3 on it's second day on jack stands and have done everything I could before dealing with the final show stopper.  The plan was new brakes and soft lines, and we found a strut mount that was totally apart.  We're all done except for the FR soft line.  I can't get the damned hard line out of the soft line fitting.  Pic below.  I have tried PB blaster for two days, a MAPP gas torch twice, nothing seems to make the flare nut want to budge.  I like the idea of trying to turn off the rubber hose fitting from the chassis hard line but don't seem to have enough space to get leverage.  I don't think there's an easy answer, but ideas on what my options are now are appreciated.  It might be time to find a brake specialist and open the wallet..

Genuis that I am sometimes, I cut the line early on so now we're committed.

I wire brush the crap out of the visible threads, heat it up and squirt in the PB or just ATF.  Slowly turning the nut in both directions eventually got it loose without breaking the steel line.

I just hit is with heat againa and went for it and stripped the nut using a flare wrench so it pretty much stripped all sides.  Decided the easiest thing was to buy a generic line and run it across the car to the distribution block.  AutoZone had a 40" NiCopp line for ten bucks which was a nice surprise.  Only one unfortunately, because I plan on wrecking at least the first one.  I can bend and flare NiCopp, so we're heading out to the garage to wreck our first line before the other AutoZone closes.

FYI PB Blaster is awesome but I've always had better luck with Aerokroil.  That's all I got...