Freeing rusty brake line fitting- got any tips?

Discussion in 'Tips 'n' Tricks Topic' started by Damon, Jul 19, 2015.

  1. Damon

    Damon Veteran Member

    Nov 16, 2000
    Philly area
    So, I got a bad front brake hose on my car (won't let caliper release).

    I've got the fitting cracked loose where the frame-side hardline mates with the flexible hose. Sure, I got it broken loose from the threads, but the hardline is trying to spin with the nut. The hardline is rusted to the inside of the nut. Obviously, I'd rather preserve the existing line than just snap it off and go through the hassle of running a fresh hardline.

    I've only had PB Blaster on it for about an hour. I'm going to douse it a few more times and try again tomorrow evening, which will be about 30 hours, give or take. Maybe that'll do it, maybe not.

    I think part of the problem is that the line is a pretty long run until it's tied down. It just twists the line but doesn't put much force into breaking the line loose from inside the nut.

    Is there a way to GENTLY BUT FIRMLY hold the hardline, without crushing it, to help apply a little more force and possibly work the line back and forth until it unglues itself from the inside of the nut?
  2. frankz

    frankz Veteran Member

    Aug 24, 2009
    You might try using a 50/50 mix of atf and acetone instead of the PB.
  3. Camaro75LT

    Camaro75LT Masshole Staff Member Lifetime Gold Member

    May 17, 2001
    Chances are if the hardline already started to twist, it's weak and may not hold if you do get the fitting free. Put a piece of wood behind it and smack it with something metal. If the fitting breaks free, great. If it doesn't, change the hard line. Nothing more fun then an unexpected brake failure..
  4. tom3

    tom3 Veteran Member

    Aug 1, 1999
    Cut the rubber hose, turn it off the hard line. Let it drain. Use heat wrench at that point to free up the fitting.
  5. krabben1

    krabben1 Veteran Member Lifetime Gold Member

    May 16, 2007
    ( . Y . )Delco
    I said sawzall,but didnt get a laugh.
  6. RD400HP

    RD400HP Member

    Dec 31, 2004
    Fowler, Ohio, USA
    I used the ole heat wrench one time sparingly at least so I thought, blew the end right off the hose scared the crap out of me so we don't use that procedure anymore.

  7. Damon

    Damon Veteran Member

    Nov 16, 2000
    Philly area
    I think I'm going with Tom's suggestion. It completely bypasses the problem, which is very trick.

    I have a feeling once I get the old flexline off the end, I'll have a better shot at getting the nut worked free from around the hardline.

    If that doesn't work, Sawzall it is, krabben. I just cut the whole front clip off the car and weld a new one on from a donor car. ;)

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