Can't remove brake lines from Master Cylinder

[rewjr69]

1990 300zx na

My car has been sitting down for 6 years, got the engine going again. Everything works perfectly but the brakes. Went to bleed brakes and discovered BMC has a leak in between the ports.

Tried to change the bmc out but the nuts that hold the brake lines are practically fused shut. Any suggestions on what tool I can use to loosen them?? FYI, I used an open ended 10mm wrench and a vice grip to no avail.

[konjiki7]

I had a similar problem on my s13. A plumber’s wrench/pipe wrench will potentially destroy the nut and crush the lines a little. Which means you may have to purchase a new nut and cut the brake line and re-flare it.

[lbreevesii]

Scrub away any rust/oxidation and soak it with PB blaster for a few days. I've had to fubar those nuts before using vice grips to get em off...

If it gets down to being that bad you'll have to reflare and put a new nut on.

[Second Shadow]

have you tried a flare nut wrench with a piece of pipe slid over it to act as a breaker bar? that typically works for me.

[Q451990]

Assuming you haven't done too much damage to the nuts, get a brand name flare nut wrench from Craftsman or Snap-on. The cheapies will flex open. Found this out the hard way on my Q.

Heath

[Richard D]

Yes... Must use a top quality flare nut wrench. They are wider than a standard wrench so there is more surface on the nut.... And they are designed to put the force on the flat of the nut which won't round off, not on the corners which will round off.

Richard

[comatoseculture]

Indeed this is THE way to do it. Name brand flare nut wrench, pb blaster, possibly another wrench/breaker bar for torque. That'll do it.