loosen brake line nuts

callbald

Senior Member
having heck of a time trying to break loose the brake line nuts on 50 year old system. I've rounded off 2 nuts. I heard of freezing them, torching them which is best for doing minimal damage?
 
Are you using 'flare nut' wrenches?
They're shaped more like a box-end wrench but with a slot in the end to slip over the brake line. They get a better grip on all 6 corners of the nut.
 

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Are you using 'flare nut' wrenches?
They're shaped more like a box-end wrench but with a small slot in the end to slip over the brake line.


Yes, that's the number one question. I'd gone years without knowing about them, so it's worth checking if the OP is aware of them.

Also, if the current brake line is a fabricated replacement (as old brake lines sometimes are) is it possible the fittings are metric?
 
I replaced the old lines on my 55 last year and the driver side nut was rounded off pretty bad. I had to use vise grips to loosen the nut. After I replaced the lines,I did buy a flare nut wrench and tighten the new nuts with the flare nut wrench. Works great.
 
yep, have flair nut wrench and it rounded it off. This 50+ year old nut is frozen on. I was jut told that AC Delco rust penetrant and inhibitor is suppose to work wonders.
 
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I have run across some brake fittings where the nut size seemed to be metric as no US size fit it. Had to go out and buy metric flare wrenches


Yes, that's the number one question. I'd gone years without knowing about them, so it's worth checking if the OP is aware of them.

Also, if the current brake line is a fabricated replacement (as old brake lines sometimes are) is it possible the fittings are metric?
 
Never heard of the freezing, but I did put some good heat on a front brake line once. heat travel up to the rubber line crimp and hose blew off. Had my head up in the fender and sounded like a fire cracker went off, couldn't hear for 2 days. Never did that again.
 
I have run across some brake fittings where the nut size seemed to be metric as no US size fit it. Had to go out and buy metric flare wrenches
The relatively new flex hose between the MC and Booster in my '55 has metric fittings. The usual/standard size wrenches don't fit the nuts but metric ones do. Luckily it's not rusty or stuck.
 
I'd go with even a propane torch, I use Mapp gas with mine, it burns hotter. I would suggest draining and blowing out the lines before getting the blue wrench out.
 
bought Benzine micro torch and that did the trick. thanks all

I don't even fight with a frozen fitting, go for the torch every time. Glad it came apart without too much trouble. As good as line wrenches are, you can still strip a nut if it is stubborn enough.
 
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