Brake lines leaking

Discussion in 'The whoa and the sway.' started by Houndogforever, Nov 21, 2020.

  1. Houndogforever

    Houndogforever Silver Level contributor

    I upgraded from power drum to factory power disc on my 67 skylark.

    I moved the proportioning valve up onto the booster and removed the hold off valve on the frame.

    I replaced all of the brake lines.
    They leak.

    Can over tightening a steel brake line into a brass prop valve damage the inverted flare in the valve?

    I leave it over night and come in the next day and it has a drop hanging on the line.

    It's just the front that is giving me fits.
  2. Utah455

    Utah455 Well-Known Member

    I just put all new SS lines on my 70. They pretty much all leaked. Every morning I checked Until none were leaking or wet with a drop. I was worried about over tightening too.

    I basically loosened a turn or two and retightened every time. I think it took four or five days for the last one to finally seat and stop.
  3. BuickV8Mike

    BuickV8Mike SD Buick Fan

    Stainless or mild steel. Stainless seems to be more challenging to seat/seal. Its likely just one that needs love. I'd try again after dressing the flared end. Good luck, Mike
  4. DasRottweiler

    DasRottweiler -BuickAddict-

    I have used copper lines when I was forced to make sharp bends/turns and/or had stubborn leaks.....JIM
  5. Houndogforever

    Houndogforever Silver Level contributor

    I'm using that Ni-cop line and filing and polishing with scotchbrite before flaring. My very first line was steel, but it needed replacing so I bent up new material.
    Sigh. I need to work more on my toys and less on my work.
    72gs4spd likes this.
  6. 1973gs

    1973gs Well-Known Member

    All lines, especially ss lines, need to be conditioned. They should be tightened, not over tightened, then back off one turn, wiggle the line around, and retighten. Also, ss lines need anti seize or special lubricant on the threads and between the fitting and line. If you just crank the fittings down to try and stop the leak, you'll just damage the threads in the wheel cylinder or the hose.
    john.schaefer77 and TrunkMonkey like this.
  7. TrunkMonkey

    TrunkMonkey Well-Known Member

    And inspect the flare mating area, they get any dings they can leak. I use 2500 wet/dry then clean with mineral spirits and compressed air.
  8. ex-probation parole

    ex-probation parole New Member

    IN LINE TUBE has a short video of how to seat these lines. It may help with your problems. I found it very helpful.

  9. Darron72Skylark

    Darron72Skylark Well-Known Member

    I have also had good luck with the NiCop brake line material. Replaced all the lines in a 66 Dodge D100 using NiCop and didn’t have a single leak.

    Which is kind of amazing since it was the first time I built brake lines or did double flare ends

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