Went to remove the front rubber brake lines for my S2000 this week. Soaked the nuts in nut buster, threw on a brake line wrench, and now I have a nice rounded nut......on both sides. The metal is ridiculously soft. I've tried multiple potential solutions to breaking the nut loose with no luck. If I can get it off I could simple cut the hard line a bit, throw a new nut on and flare the end but my issue is the nut.
Throw some pliers on it, it just deforms the metal.
Chisl, same thing.
Anyone have any tips/tricks/recommendations?
Just went through this on my dad's Xterra.
The answer was hefty vise grips cranked as tight as my hands could manage.
In reply to DirtyBird222 :
Is there enough space to get a set of locking pliers on the nut? That's usually how I end up dealing with stuck hard line nuts. Two pairs of big locking pliers clamped super tight on the nuts themselves.
NOHOME
MegaDork
8/30/23 2:01 p.m.
I own an very small pipe wrench for just these kind of situations. 
Getting the last of this done on my Rabbit. Cranked vise grips just cut metal. I had to dremel them off.
This is the interface from the hardline to the rubber line?
Well, from the sound of it, you are already headed for cut a bit and reflare with a new nut. Cut the brake line just above the nut. Get new soft lines and nuts, put nuts on and flare. Reassemble and soup...
How much hardline are you losing with the nut length?
Apexcarver said:
This is the interface from the hardline to the rubber line?
Well, from the sound of it, you are already headed for cut a bit and reflare with a new nut. Cut the brake line just above the nut. Get new soft lines and nuts, put nuts on and flare. Reassemble and soup...
How much hardline are you losing with the nut length?
This is correct. Not much, whatever the nut length is, so half an inch is my guestimate. I could def still make it work. I could also just make new lines too.
It sounds like you're already to the point of cutting the line, but don't neglect the heat suggestion.
Heat does wonders for loosening up threads!
Vicegrips and a small tip on an oxy-acetylene torch.
buzzboy
SuperDork
8/31/23 2:03 p.m.
I was scared of doing heat on a brake line because I couldn't remember if brake fluid was flammable. I got that rounded nut off no trouble. I was already planning to replace the hardline anyway, just trying to save the new hose.
Heating a tube nut can and will cause the flex hose to pop like a firecracker. Try it on a scrap hose, it's fun! The rubber heats up inside the steel crimp and has nowhere to expand to until it is soft enough that it ejects itself forcefully, and loudly.
If you are changing the flex hose, just cut the hardline and put a new nut on it. If you are not changing the flex hose, cut the hardline, put a new nut on it, and use a socket to remove the old nut. 3/8" sockets are a perfect fit to hammer over once-10mm tube nuts.
In the future, if it's stuck that hard on the brake line, remove the clip and unthread the flex hose from the stationary tube nut. THEN you can apply heat to free the nut on the hardline.
