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Can't stop the weep!

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  • Brakes: Can't stop the weep!

    Hi, thought my brake line woes were past 2 years ago, finally got all my new Cunifer lines and DOT5 sealed up. Recently, since still just a chassis, removed MC to return to Jim Turner for adding the port to enable a reservoir for refill mounted on firewall. Ever since, can't get the lines to stop very tiny weep (overnight to show). Removed line and remade both ends, as well as I know how (and the rest of the system has been dry, most the 'first time'). Don't know what else to to do. Tightened as tight as possible (over three nights of trying to stop the weep). MC ports LOOK ok but really hard to see in there if somehow scored, don't know how, Always very careful no burrs, blew out components w/ brake cleaner before assembly, etc.. . If it WERE the MC ports now, is there anyway to replace (or have NAPA or ?) replace just those MC fittings? Or cost more than buying a whole new modified cylinder (again) from Jim?
    attached photos of my flare. one problem I noticed with this 3/8' Cunifer, is a bit thick, so I've had to gently file away the pinched area that swells; get it to where the nut freely turns and seats. And, worked on all my OTHER many fittings even before I started fine-tuning them a bit like that.

    I did DOT 5 so no cylinders would rust out (already had the Cunifer, overkill in that case I know). If I had it to do over again, would have stuck with DOT3 I think. But hate the thought of rebuilding ALL of the brand new wheel and M/C again to clean the DOT 5 out :-(.
    Anything look amiss with my flares? Or other tips? I'd never done flaring before, but have a good hydraulic set, practiced a LOT, and did the fuel lines after the brakes, so feel I'm "doing them right" at this point.

    Finally completely out of my 3/8" line, could maybe get one more flare out of existing. BUT, have made multiple and always end up with a slight weep one end or the other. Only this set of two lines, from pressure valves to cylinder!!! all others sealed. So frustrating!


    Thanks. Click image for larger version  Name:	brake line flare.jpg Views:	0 Size:	19.5 KB ID:	1892063 Click image for larger version  Name:	brake line fare side2.jpg Views:	0 Size:	8.0 KB ID:	1892065 Click image for larger version  Name:	brake line fare side.jpg Views:	0 Size:	59.8 KB ID:	1892066 Click image for larger version  Name:	brake fluid weep.jpg Views:	0 Size:	103.9 KB ID:	1892067 Click image for larger version  Name:	MC.jpg Views:	0 Size:	89.6 KB ID:	1892068
    Last edited by bsrosell; 04-27-2021, 06:20 PM.

  • #2
    Hey up Barry, mask making slack off a bit? last job i did like this i had the same problem. i cured it by only making the final flare half way, and leaving the fitting and seat in the MC to finish form the flare. i found pushing the center down about 2/3 of the way seemed to work. i cant explain why it works but on the 60 Ragtop it worked! keep at it! Luck Doofus

    Comment


    • #3
      Wondering perhaps the flare nuts are bottoming out in the thread before enough pressure is applied to the flare? That would explain your success in dealing with it, too, Doofus.
      Gord Richmond, within Weasel range of the Alberta Badlands

      Comment


      • #4
        Even though I’ve touted the ease-of-working benefits of CuNiFer in the past (Feb 2020 - Champ brakes discussion) I’m just wondering if they’re almost too soft in some occasions.

        Most of the aftermarket pre-flared lengths seem to be coated steel; are there any OEMs using CuNiFer that we know of? Has industry created an alloy that is easy to bend but overly easy to distort?

        I thought I had the nuts tight at every spot, but I wept at each one. Only tightening to far more than I was comfortable with was I able to stop them all.
        Last edited by NCDave51; 04-28-2021, 11:31 AM.

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        • #5
          NCDave51

          Say paper dude , I have something to add to your thoughts with ref. to the CuNiFer line issues. It JUST dawned on me I have the same 'weeping' troubles on my 86 Jeep CJ-7. I just added a fuel pressure regulator and a liquid filled fuel pressure gage - used CNF factory made-to-length lines (it just happened to work out for the plumbing I needed) AND I am having a devil of a time getting several of the factory fittings to stop weeping.

          So NOW it dawns on me I have the same problem you folks are having BUT my stuff is all factory flares / fittings. and what has been MY fix ? Good old P.C.M.C. normal protocol ..... get a bigger tool & more torque ( no sweat if it breaks......I know a guy in the warranty dept.....he will make it go away).

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          • #6
            Interesting that you keep calling your Brake Lines 3/8" Cunifer!
            The FITTINGS have that wrench size, but the LINES "Should" be 3/16", if that were True it WOULD be a Problem!
            StudeRich
            Second Generation Stude Driver,
            Proud '54 Starliner Owner

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            • #7
              Interesting discussion! I'm having the same leak issues with the 3/16" Cunifer lines I've installed on my Indy car replica. I cannot get them to stop leaking. I even bought the very expensive English flare tool from FedHill after the first lines leaked so badly. The Cunifer is easy to bend, and I had to make some twisty lines to clear the frame rails. I've flared steel tube before, don't remember having leak issues. But, after reading the comments, maybe I just need to tighten all the fittings on the Cunifer tubes even more. It's the first time I've used Cunifer. I just hope my 5/16" Cunifer gas line with AN fittings doesn't leak also.

              Click image for larger version

Name:	indy car chassis front Mar 2021.JPG
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              Indy car chassis with body removed.

              Click image for larger version

Name:	brake tube left front 3.JPG
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              Left and right front brake lines during installation - Cunifer. Note all the wiring is laced to bundle it.
              Gary Ash
              Dartmouth, Mass.

              '32 Indy car replica (in progress)
              ’41 Commander Land Cruiser
              '48 M5
              '65 Wagonaire Commander
              '63 Wagonaire Standard
              web site at http://www.studegarage.com

              Comment


              • #8
                They make copper flare seat gaskets.

                Perfect for stainless lines, and dot 5 fluid problems too.

                Parker - 3/16" Tube OD, 45° Copper Flared Tube Gasket - Flare Ends | USA Tool & Supply (usatoolandsupply.com)
                Bez Auto Alchemy
                573-318-8948
                http://bezautoalchemy.com


                "Don't believe every internet quote" Abe Lincoln

                Comment


                • #9
                  The Parker copper gaskets look like a good solution. However, USA Tool has a $50 minimum order, tough to reach with $0.80 parts. MSC Industrial Supply has the gaskets for $0.84 each but wants $12.95 for shipping. I bought 20. Some parts on Amazon, as well.
                  Gary Ash
                  Dartmouth, Mass.

                  '32 Indy car replica (in progress)
                  ’41 Commander Land Cruiser
                  '48 M5
                  '65 Wagonaire Commander
                  '63 Wagonaire Standard
                  web site at http://www.studegarage.com

                  Comment


                  • #10
                    The only time I've had any flare I've made weep regardless of tube material was if I over tightend the flaring tool in the final step, (which it looks like you may have done) and crushed the flare or when I didn't tighten the fittings enough when using DOT5. I've used copper/nickel tubing many times and have never had an issue with it. Inverted flare fitting shouldn't require more than about 12 ft lbs torque, and banjo bolts around 22 ft lbs even with DOT 5 fluid. By the way, yes, Volvo has been using it since the '70s.

                    Comment


                    • #11
                      I haven't had a single problem with leaks, seeps, or weeps since I started installing the appropriate size nitrile "O" ring into the fittings before tightening down the flared end into it...period. Fuel lines, brake lines, transmission cooler lines, etc, etc...

                      Comment


                      • #12
                        An "O" ring of rubber is asking for trouble. They can not possibly hold the pressures generated by braking systems. You are talking at least 1200 lbs/sq inch. If they didn't leak it's because you tightened them past the rubber, and the metal is actually doing the sealing.
                        I only posted US Tools as an example. I have purchased the copper flare gaskets from Graingers as well as made them up from some sterling silver I had left over from my jewelry days.
                        Bez Auto Alchemy
                        573-318-8948
                        http://bezautoalchemy.com


                        "Don't believe every internet quote" Abe Lincoln

                        Comment


                        • #13
                          Thanks guys. (ha! yes, I've been reaching for my 3/8" flare wrench so often started saying 3/8"lines vs 3/16" :-)
                          I'm thinking Doofus is right; very subjective "how much too much" pressure, with my hydraulic pump flaring tool. Would make sense to back off and let it spread and seat itself. Will try that first.
                          Re: the comments about 'tighten it some more", that was the answer for most of the OTHER fittings in the system, finally stopped weeping, but these I literally rounded nuts off and/or could not get ANY more torque on them. Maybe a slightly different flare on the M/C and the pressure valves in the Turner kit, since those have been the most problem to seal, and have done flaring the same (and multiple times) for both of those. Will let you all know how backing off on the 2nd flare works. Wish I'd known about those seals before I started the whole job 2 years ago, would have saved a LOT of frustration building the whole system from scratch and DOT5! :-) (hope my fuel lines fair better; have yet to put gas in the tank to try and fire it up yet!)

                          Comment


                          • #14
                            bezhawk - Nitrile being the Operative word...not "rubber".

                            Nitrile rubber, also known as nitrile butadiene rubber, NBR, Buna-N, and acrylonitrile butadiene rubber, is a synthetic rubber derived from acrylonitrile (ACN) and butadiene.[1] Trade names include Perbunan, Nipol, Krynac and Europrene. This rubber is unusual in being resistant to oil, fuel, and other chemicals.

                            NBR is used in the automotive and aeronautical industry to make fuel and oil handling hoses, seals, grommets, and self-sealing fuel tanks.[2] It is used in the nuclear industry to make protective gloves. NBR's stability at high temperatures from −40 to 108 °C (−40 to 226 °F) makes it an ideal material for aeronautical applications. Nitrile butadiene is also used to produce moulded goods, footwear, adhesives, sealants, sponges, expanded foams, and floor mats.

                            The "O" rings ARE compressed between the fitting and the flare, but not so they are crushed and destroyed.... and they DO hold the brake pressure without leaking. I have been using them in all my fluid systems, for decades, and have never had any sort of failure....
                            Last edited by 345 DeSoto; 04-29-2021, 12:04 PM.

                            Comment


                            • #15
                              I called Tim at FedHill, the main supplier of the Cunifer tubing. He was surprised that we couldn't get the lines sealed. He suggested a couple of things.

                              1. Look into the fitting to be sure the cone isn't damaged or scored.
                              2. With the nut slid back, push the tube into the fitting and see how deep it goes and how much thread is exposed. Also look to see if the diameter of the flare is big enough to engage a good portion of the cone.
                              3. If short nuts are being used, try screwing a bare short nut into the fitting to be sure it doesn't run out of thread before pressing the back of the flare. Long nuts may be required in some fittings.
                              4. He wasn't too concerned about the possibility of over-forming the flare as the tubing is soft enough to deform if the nut is pressing correctly.
                              5. Check the flare and cone in the fitting to see if there are marks from contact. Some marking is expected from the nut and the cone contacting the tube. But, there shouldn't be scratches or grooves that run from center to outside, just round and round marks.
                              5. He did ask me where I bought the nuts. While I got some from FedHill, I got some others from the local chain parts store. Could be I bought less-than-perfect quality nuts.
                              6. He thought that the copper gaskets shouldn't be needed, especially on 3/16" tube.

                              I'll be checking these issues on my car. With as many leaks as I have, I must be doing something wrong.
                              Gary Ash
                              Dartmouth, Mass.

                              '32 Indy car replica (in progress)
                              ’41 Commander Land Cruiser
                              '48 M5
                              '65 Wagonaire Commander
                              '63 Wagonaire Standard
                              web site at http://www.studegarage.com

                              Comment

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