Compression fittings

Brakes for your Classic Mopar

  1. dartfreak75

    dartfreak75 Restore it, Dont part it! FABO Gold Member

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    Who here uses them? I have used them on damn near every vehicle I've ever owned in the last 20 years and never ever had a issue or fail with them. I was reading an article today saying that you should never ever use them on brakes I have used them on brakes fuel lines etc and like I said never had a problem. What are you guys opinion?

    Compression Fitting Union CF 38 Three Eigths.jpg

    brass_compression_fittings.jpg
     
  2. 4spdragtop

    4spdragtop CONGRATS NORTH AMERICA! FABO Gold Member

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    Hard no.
     
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    • coloradohill

      coloradohill Well-Known Member

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      I’ve used them on trans lines Ect. Not on a brake line.
       
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      • 67Dart273

        67Dart273 FABO Gold Member FABO Gold Member

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        Those fittings (The common brass "short nut" fittings) don't belong on automobiles PERIOD. I would not use them on either brake or fuel lines. There is no vibration resistance. Only exception is the smaller 1/8 oil pressure line which is inherently stronger because the line is smaller

        There exists (used to) AIR BRAKE compression fittings, which used more robust ferrules and long nuts resembling flare nuts. These are/ were far superior. They were also used on the nylon brake tubing which is OD sized same as copper/ aluminum tube

        Also notice the other type air brake fittings have an internal ferrule to support the ID of the tube from collapse because of the ferrule

        tation-air-brake-fittings.jpg?width=232&name=compression-style-transportation-air-brake-fittings.jpg

        Air_Brake_Copper_Tubing_Diagram_Fast_Fittings_large.jpg

        There also exists STEEL compressin fittings which can be used on such things as power steering repairs. You cut off the old hose from the formed steel tube ends, crimp up a hydraulic hose with these type compression fittings, and then put them onto the steel tube ends

        The common ones I was familiar with "back then" were for dual braid hydraulic hose, came in straight and 90

        ERM%20Ermetto%202-500x500.jpg
         
        Last edited: Aug 9, 2021
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        • RustyRatRod

          RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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          Nope. Not for brakes.
           
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          • dartfreak75

            dartfreak75 Restore it, Dont part it! FABO Gold Member

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            Wow I can't believe I'm the only one that uses them lol I always thought thats what they were made for.
             
          • sireland67

            sireland67 FABO Gold Member FABO Gold Member

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            Never use them for hydralic pressure, they will fail.
            Oil pressure line line, ok because oil pressure is low pressure.
             
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            • Scamp Rhonda

              Scamp Rhonda Well-Known Member

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              I just went through this with my Scamp. Snapped a brake line off and had to build a new one. Went to AutoZone and they loaned me a brake line flaring tool for free. Watched a couple of videos on YouTube and did a few practice flares and now I'm a pro, lol. It was actually one of the easier things I've done on the car and I really enjoyed crafting my own line. I also have a transmission line to fix also and when I'm done I can bring the tool back and it doesn't cost me a dime. But I think I'm gonna keep it! Here's one from Amazon that's about half the price as AutoZone's.
              Auto Double Flaring Tool Kit Copper Aluminum Brake Line and Brass Tubing Tools 45 Degree Flares https://www.amazon.com/dp/B07T66MJG3/?tag=fabo03-20
               
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              • dartfreak75

                dartfreak75 Restore it, Dont part it! FABO Gold Member

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                Yea I have one i just learned that you have to have double flares recently lol
                 
              • Greasyfingers

                Greasyfingers Well-Known Member

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                Used for an emergency repair to get home from an off-road trip, but replaced line within day of getting home. Never safe for permanent repair.
                 
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                • 67Dart273

                  67Dart273 FABO Gold Member FABO Gold Member

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                  AND NOW IT'S TIME FOR another annoying story from the old days

                  This is the Baldy road coming E to corner of Boyer, and in the time I am speaking, about 1976 ish, there was nothing to the right of Boyer, only scrub land, and if you look there are power lines running along, and there was a 1/2 lane dirt not-quite-an power company access road/ trail across Boyer from Baldy

                  baldy.jpg

                  So a then friend of mine had bought a ?67? ?66? Fairlane based Ranchero, and lived up "Baldy hill" a ways. One afternoon he related what had happened. He had bought the rig from a used dealer, and had not yet been under it. he was roaring down Baldy towards town, likely doing roughly twice the advertised 35mph speed limit, and applied the brakes to stop at Boyer. AND IT WAS JUST LIKE IN THE SONG...."sorta like steppin on a plumb"....and the Ranchero kept RIGHT ON GOIN across Boyer and bumping and banging down the "access road" until he finally got it stopped

                  WHY?? did this occur?

                  BECAUSE SOMEBODY had damaged the brake lines while pulling the transmission AND HAD SPLICED THEM back together using FUEL HOSE AND CLAMPS!!!!!!!!!!!!!!!
                   
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                  • Scamp Rhonda

                    Scamp Rhonda Well-Known Member

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                    Man if someone is that dum they shouldn't be allowed to play with tools:wtf:
                     
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                    • 67Dart273

                      67Dart273 FABO Gold Member FABO Gold Member

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                      I can assure there has been, is, and will be worse

                       
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                      • RustyRatRod

                        RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                        They're not made for high pressure. All that holds them together are the ferules that squeeze down around the lines. They are no way made for pressures exceeding 1000 PSI. I think brake pressures can exceed 3000 PSI in some instances. Just because you can, doesn't mean you should. If you want to connect lines together like that, the correct and SAFE way is with a flare union.
                         
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                        • Tooljunkie

                          Tooljunkie King of cobble/master of the broken bolt FABO Gold Member

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                          Those ferrules crush into the softer nylon or copper line. That was the day i stopped watching scotty kilmer. He repaired a brake line with a compression union.
                          The ones designed for steel line, aeroquip fittings or swage lock fittings i would consider. But im well versed in flaring brake lines so i go the cheaper route and make a proper flare.
                           
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                          • RustyRatRod

                            RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                            Cheaper and safer. Two words rarely used in the same sentence.
                             
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                            • Jeremiah

                              Jeremiah Well-Known Member

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                              I have redone many cars to remove the compression fittings installed by current or previous owner. One was on a 145+mph 3300 lb drag car. That was an eye opener with 8-10 compression fittings.

                              While they might work in most cases I always figured if something happened and the insurance company investigator found that the owner installed non-DOT brake parts there may negligence factored towards the owner. That might just be me being paranoid though. Wither way it's best to get a roll of CuNi and a good (Mastercool , etc) flaring tool to land everything with double flares.
                               
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