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    Stock brake hardline size?

    When replacing the hardlines, what is the proper size and flare diameter? It seems that 3/16" hard line is right, but it seems odd to have imperial measurements on the car.

    Second, I think I read that the stock lines are a bubble flare, but I was going to use a double flare tool. I just rented one to replace/repair the lines on the rear of my MJ, and I might just buy the tool to have on-hand. The tool for rent at AZ/AAP is all imperial sizes, so if I need metric for the E30, I need to go another route.

    Thanks...
    Patrick Henry

    1989 325iC build: http://www.r3vlimited.com/board/showthread.php?t=316880



    #2
    Originally posted by phenryiv1 View Post
    Second, I think I read that the stock lines are a bubble flare, but I was going to use a double flare tool. I just rented one to replace/repair the lines on the rear of my MJ, and I might just buy the tool to have on-hand. The tool for rent at AZ/AAP is all imperial sizes, so if I need metric for the E30, I need to go another route.

    Thanks...
    The e30 uses a bubble flair. The double flair is different.

    Not 100% sure on the actual line size though.

    Erik

    Comment


      #3
      Hi,

      I replaced some hard lines (fuel and brake) on my vert this last summer. Here's a post from the local forum where I explained everything.

      http://forum.norcale30.com/showthread.php?t=7841

      Unfortunately, if I haven't already represented myself as such on this forum, I am a wordy m-fer.

      Here's the parts from that thread I think you'll want:

      "Thought I'd just update this if anyone's curious about making their own brake lines. I used line and fittings from Fed hill (the above link), a flaring tool from summit racing, a tubing bender from autozone, and a pipe cutter and files from home depot."

      and

      "
      2. T1 - 3/16"/4.75mm OD tubing, our brake lines' size.

      3. M1-3, 10mm x 1.0 Fine thread, male nut with non-threaded lead - SAE flare or DIN flare. Brake line fittings. Note: they sell these in packs, which is much cheaper."

      The website those initial numbers refer to ("T-1") is www.fedhillusa.com

      As mentioned, double =/= bubble flare. And technically our brake lines aren't imperial size, they're 4.75 mm. It just happens to be 3/16", for whatever reason. The summit racing flaring tool was around $40, I'd recommend it.
      87 325iC 90 325iC 88 325iC 87 325i 87 325iS 87 325eS

      Comment


        #4
        Whoops, cheaper than I remember. $22.

        http://www.summitracing.com/parts/OTC-4504/

        It'll also do your fuel lines (8mm) if you need it to.

        -Brett
        87 325iC 90 325iC 88 325iC 87 325i 87 325iS 87 325eS

        Comment


          #5
          Originally posted by Lunner View Post
          Hi,

          I replaced some hard lines (fuel and brake) on my vert this last summer. Here's a post from the local forum where I explained everything.

          http://forum.norcale30.com/showthread.php?t=7841

          Unfortunately, if I haven't already represented myself as such on this forum, I am a wordy m-fer.

          Here's the parts from that thread I think you'll want:

          "Thought I'd just update this if anyone's curious about making their own brake lines. I used line and fittings from Fed hill (the above link), a flaring tool from summit racing, a tubing bender from autozone, and a pipe cutter and files from home depot."

          and

          "
          2. T1 - 3/16"/4.75mm OD tubing, our brake lines' size.

          3. M1-3, 10mm x 1.0 Fine thread, male nut with non-threaded lead - SAE flare or DIN flare. Brake line fittings. Note: they sell these in packs, which is much cheaper."

          The website those initial numbers refer to ("T-1") is www.fedhillusa.com

          As mentioned, double =/= bubble flare. And technically our brake lines aren't imperial size, they're 4.75 mm. It just happens to be 3/16", for whatever reason. The summit racing flaring tool was around $40, I'd recommend it.
          I like wordy M-F'ers. They tend to include all of the important details.

          To clarify a point from my initial post, I was aware that bubble flare =/= double flare, but despite my wordiness in my initial post, I left out the fact that I had read on bf.c that you can purchase a union fitting that will allow joining bubble flares to double flares.

          It sucks that the E30 uses bubble flares and my truck uses a double flare. I was going to just buy a tool if it would let me do both, but maybe I'll just "rent" them from AZ/AAP (assumming that they have a bubble tool) or just buy the pre-bent lines from a dealership.
          Patrick Henry

          1989 325iC build: http://www.r3vlimited.com/board/showthread.php?t=316880


          Comment


            #6
            The lines from the dealership are straight. You will have to bend them. I'd suggest a high quality pair of brake bending pliers to do so, as the rear hardlines have a lot of tight radius bends on them.

            Flaring is a pain if you have the $40 screw-type tool. I've always dreamed of getting one of those hydraulic units, but then again, that's a lot of cash to make just a handful of flares in my lifetime.

            Originally posted by whysimon
            WTF is hello Kitty (I'm 28 with no kids and I don't have cable)

            Comment


              #7
              Originally posted by FredK View Post
              The lines from the dealership are straight. You will have to bend them. I'd suggest a high quality pair of brake bending pliers to do so, as the rear hardlines have a lot of tight radius bends on them.
              Good to know. I have one of the small hand radius benders. Worked fine for my truck, but the space to work is pretty wide open under there. May not be the case on the E30.
              Patrick Henry

              1989 325iC build: http://www.r3vlimited.com/board/showthread.php?t=316880


              Comment


                #8
                Originally posted by phenryiv1 View Post
                Good to know. I have one of the small hand radius benders. Worked fine for my truck, but the space to work is pretty wide open under there. May not be the case on the E30.
                The cunifer tubing that fedhill sends is real easy to work with.

                This means two things,

                a) easier to kink, so I bought a whole bunch extra

                b) easier to slightly bend in place with your hands to make fit when you install it. Basically what I did was pull the old brake line out, use it as a mold of sorts for the new brake lines, and then if I had any problems they were slight enough that I could 'fix' it while I was under the car.
                87 325iC 90 325iC 88 325iC 87 325i 87 325iS 87 325eS

                Comment


                  #9
                  Do the factory OE hard lines you buy at the dealer come with the fittings already on the ends? I would assume so. I realize they are straight.

                  Has anyone ever purchased the long hard line that goes from the front to the back for the dealer? Seems like it would be something that would show up all bent, but maybe it's packaged up in a box or something. Just curious as I might be undertaking this project.
                  89 325is track project / 05 x5 / 99 M3
                  E30 stuff for sale | Parts I'm looking for

                  Comment


                    #10
                    Yes. The OE hardlines come pre-flared with the fittings already on the end. I believe the really long line from the proportioning valve to the rear distribution tee comes in a fairly large diameter coil.

                    Originally posted by whysimon
                    WTF is hello Kitty (I'm 28 with no kids and I don't have cable)

                    Comment


                      #11
                      Did my brake lines front to rear.

                      3/16th line, bubble flair, M10 fitting. 3/16th is extremly close to 4.5mm or whatever it is.

                      Autozone, Napa, pepboys all have these lines. I bought a 60 inch line from pepboys from the front to the back, then a union, then a 20 inch line from that to the three way T above the differential.

                      Buy a Majority of lines, from 12" to 30 Inch, many of them, as you may bork one up. they're cheap enough. I'd reccomend Napa for the cheapest and largest variaty of lines, but it all depends what they have in stock.

                      Buy as many unions(To join two brake lines together) as you can, I'd reccomend pepboys for unions as they sell them for 2.99 compared to napa's 6.99 unions. And pepboys seems of better quality as well.

                      Ironically the OEM BMW lines have 7/16th fittings. Aftermarket lines all have 12mm fittings.

                      I bought one OEM bmw 12" line from the dealership for $12, it was of very high quality, they seem to have a coating on them. but I dont think I'd waste money on doing my whole system in them.

                      I used thread tape on all of my fittings, just to make sure. I was also very stupid and i bypassed my pressure regulator, the little thing that sits in your driver wheel well. Don't do that, as it'll decrease your braking performance alot. I need to unbypass it now -_-
                      1985 325e M50TU(Sold)
                      1991 318is Slicktop (Sold)
                      1990 325is Brilliantrot S50/5 Lug Swapped.
                      1992 525i Manual shitbox Winter Beater

                      Comment


                        #12
                        The english 3/16(in) line is so close to metric 4.75(mm) line because 3/16(in)=0.1875(in) and 4.75mm/25.4(mm/in)=0.1870(in). The OD difference is ony 0.0005"

                        Comment


                          #13
                          http://www.youtube.com/watch?v=HVbHk0kkX8k this seems to explain how to make the appropriate flares if needs be.

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