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Technical Sealer for NPT brake line fittings

Discussion in 'The Hokey Ass Message Board' started by Doublepumper, Apr 1, 2019.

  1. Doublepumper
    Joined: Jun 26, 2016
    Posts: 1,079

    Doublepumper
    Member

    Need some teachin from the experts....I poked around for info, but didn't really find any definitive answers. Can anyone tell me what the proper sealant is to use on NPT fittings used in brake lines? I realize nothing on flare fittings other than possibly a small amount of anti seize on the threads and under the fitting behind the flare. I'm looking at sealing the threads on NPT fittings only and want a sealant that is compatible with brake fluid. I want to do this one time and get it right. Thanks guys!
     
  2. squirrel
    Joined: Sep 23, 2004
    Posts: 49,789

    squirrel
    Member

    a little bit of teflon, either paste or tape, should be fine.
     
  3. 3spd
    Joined: May 2, 2009
    Posts: 549

    3spd
    Member

    CNC Inc, a aftermarket brake parts manufacturer told me to use blue loctite on their NPT brake fittings.
     
  4. treb11
    Joined: Jan 21, 2006
    Posts: 3,690

    treb11
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  5. Doublepumper
    Joined: Jun 26, 2016
    Posts: 1,079

    Doublepumper
    Member

    I had read about using blue loctite and was going to use it.....but wasn't sure about it being compatible with brake fluid. Same with the teflon tape or paste. Just wondering if there is something better suited for brake fluid.
     
  6. Doublepumper
    Joined: Jun 26, 2016
    Posts: 1,079

    Doublepumper
    Member

    This is what I came up with as being the best alternative....don't know.
     
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  7. squirrel
    Joined: Sep 23, 2004
    Posts: 49,789

    squirrel
    Member

    There might be a "best", but there also might be some alternatives that work fine with no problems.

    If you're really worried about it, go ahead and get the Permatex sealer. I've never found a need for it.
     
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  8. Doublepumper
    Joined: Jun 26, 2016
    Posts: 1,079

    Doublepumper
    Member

    I actually like the idea of using teflon tape, do to it being a good thread filler and lube between aluminum, brass and steel components and fittings. I was unsure if it was compatible with brake fluid that seems to attack most everything.
    I appreciate all of the input you all provided. Thanks!
     
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  9. squirrel
    Joined: Sep 23, 2004
    Posts: 49,789

    squirrel
    Member

    Brake fluid attacks paint, but it doesn't attack everything. Teflon is tough stuff, not much out there will dissolve it.
     
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  10. V8 Bob
    Joined: Feb 6, 2007
    Posts: 2,771

    V8 Bob
    ALLIANCE MEMBER

    It's best to stay away from Teflon tape on any brake/fuel system. Just use any good pipe thread sealant (paste) with Teflon or PTFE, and only on pipe fittings.
     
    Last edited: Apr 1, 2019
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  11. 302GMC
    Joined: Dec 15, 2005
    Posts: 6,964

    302GMC
    Member
    from Idaho

    Never used anything on brake fittings … if a leak occurs, you're doing something wrong.
     
  12. Yep, you should not need any sealer. If you need some assurance put a dab of teflon paste on the threads.
     
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  13. woodiewagon46
    Joined: Mar 14, 2013
    Posts: 1,936

    woodiewagon46
    Member
    from New York

    Also recommend the Permatex 54540. I use it on the threads and it works great.
     
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  14. Doublepumper
    Joined: Jun 26, 2016
    Posts: 1,079

    Doublepumper
    Member

    Well, I checked my stash of PTFE thread sealers and besides teflon tape I have some Rectorseal and Blue Monster, both with PTFE. I checked the PDS's on both and the Rectorseal specifically states use with brake fluid, so I'll use it and hope for the best. Hate to spend the big money for the Permatex sealant 54540 when I only need a very small amount to do the job. If I didn't already have the PTFE sealant I'd probably give it a try.
    Again, I really appreciate all your input....that's why I'm here!
     
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  15. 41rodderz
    Joined: Sep 27, 2010
    Posts: 5,587

    41rodderz
    Member
    from Oregon

    Rectorseal ? Sounds more like a lower part medicine. Post bathroom break?
     
  16. Doublepumper
    Joined: Jun 26, 2016
    Posts: 1,079

    Doublepumper
    Member

    It does and would probably be better than nothing......in a pinch.
     
  17. 3spd
    Joined: May 2, 2009
    Posts: 549

    3spd
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    That is only true for flared/tapered fittings - some brake parts use NPT threads and do require the use of sleant.
     
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  18. I’ve never seen npt brake fittings, where would you see them?
     
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  19. prpmmp
    Joined: Dec 12, 2011
    Posts: 1,080

    prpmmp
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    scotty t likes this.
  20. Rich S.
    Joined: Jul 22, 2016
    Posts: 296

    Rich S.

    Rectum...Nearly killed him.


    Sent from my iPhone using The H.A.M.B. mobile app
     
  21. OLDSMAN
    Joined: Jul 20, 2006
    Posts: 2,422

    OLDSMAN
    BANNED

    I have never seen NPT fittings on brake lines. They are always flare fittings and they require no sealers st all
     
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  22. scrappybunch
    Joined: Nov 16, 2011
    Posts: 356

    scrappybunch
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    from nj

    19Eddy30 likes this.
  23. fatabone
    Joined: Nov 3, 2003
    Posts: 1,437

    fatabone
    Member

    We have never used a sealant on any brake fittings..
     
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  24. NPT is tapered,and should seal itself.Afraid of corrosion locking parts together? Light coat of anti-seize .
     
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  25. anthony myrick
    Joined: Sep 4, 2009
    Posts: 8,626

    anthony myrick
    Member

    I thought you just torqued em down a bunch. Never used anything but the mechanical seal
     
  26. theres a whole bunch of brake system fittings and parts with NPT pipe threads.
    heres just one and used quite a bit. these happen to have sealer on them already
    [​IMG]
     
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  27. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,980

    s55mercury66
    Member
    from SW Wyoming

    I have always used teflon tape, and only had trouble with it one time, and that was a very slow weep with DOT 5 fluid.
     
  28. OLDSMAN
    Joined: Jul 20, 2006
    Posts: 2,422

    OLDSMAN
    BANNED

    Ok if you use aftermarket flex lines there would be NPT fittings, but OE lines are not NPT . Actually NPT fittings shouldn't require any sealer because they are tapered do they seal when tightened
     
  29. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 3,510

    2OLD2FAST
    Member
    from illinois

    In a perfect world taper cut threads would always seal , we all ( should) know , that ain't happening . Thread dope , sealer , paste , tape is used as much as a friction reducer - anti- gall agent as much as anything.
     
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  30. o_O

    I bet there's several dozen different fittings used brake systems that utilize NPT. I don't think you can get all of them into one vehicle, and it's entirely possible to build a brake system without any. None the less NPT brake fittings are out there in force and require some type of sealer.
     
    19Eddy30 and TrailerTrashToo like this.

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