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Thread: More on BMW brake line failures

  1. #1
    Pepperfool GSAddict's Avatar
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    More on BMW brake line failures

    This is getting very serious..............
    http://www.advrider.com/forums/showt...3#post19102823

    I would suggest replacing your old brake lines if your bike is pre 2005, unless it has braided SS ones.
    '
    Ufda happens..........

    It's all about the details.

  2. #2
    Registered User Bmandiego's Avatar
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    The brakes on my 2000 r1100rtp recently faded, locked-up for a time, then the front line split near the front junction. It had the original lines. All the rubber on my bike was in bad shape.
    Most of the brake problems were found when I was parked in the garage, just checking the bike out after all the fluids were changed. I feel very lucky.
    There was no visual indication of a failure.
    I now have Spiegler SS lines. The brakes were grabby before, they are much smoother now.
    2000 R1100RT-P

  3. #3
    Registered User arthurdent's Avatar
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    what years are most involved?

    Wondering how far this goes. Is it centered around 99 - 01 or does it go beyond? I'll check the lines on my 04 GS, but don't expect to find much evidence since the PO had the reservoirs flushed just before I acquired the bike.

  4. #4
    Registered User lkchris's Avatar
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    While you're at it, replace your tires if they're worn.

    And, be sure to use specified brake fluid and change it according to specified schedule and inspect your hoses according to the schedule as well.

    Other than aftermarket hype, I seriously doubt there's much data that metal-sheathed teflon lines are a superior solution.

    It's a useful heads up. Shouldn't be considered a crisis.


    PS IMHO the discussion goes much better if "hoses" is used to describe the rubber things and "lines" is used to describe the metal things.
    Kent Christensen
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    '12 R1200RT, '02 R1100S, '84 R80G/S

  5. #5
    Registered User NavyDad's Avatar
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    It has nothing to do with certain years or models. It has to do with AGE. Brake lines and other rubber or plastics parts are affected by the elements and not just BMW's but all bikes, cars, trucks, etc. If you are riding a ten year old bike you are going to experience a problem sooner or later regardless of mileage. My 04 RT hasn't had any issues yet, but new stainless lines are on my winter list of things to do. The bike will have 65,000 on it by then so I am going to do the spline lube thing also. I know guys who wouldn't be caught dead in a ten year old car because they say a car that old just isn't reliable. These are the same guys who throw six kinds of tantrums if their ten year old bike needs any attention. Go figure.

  6. #6
    Registered User ANDYVH's Avatar
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    I have 17 years as a field engineer for the worlds largest hydraulic hose manufacturer, and I can tell you this statement is completely wrong: "Other than aftermarket hype, I seriously doubt there's much data that metal-sheathed teflon lines are a superior solution." Standard OEM brake hoses are some of the cheapest construction hoses on the hydraulic hose market, period. If you really value your life and your bike, I would not use them on a bike. Its nothing about hype, simply the truth from the inside of the industry. I am very familiar with the construction, components and manufacturing of both types of brake hose.

    Standard brake hose is simply the minimum cost product the manufacturer can use for brake applications that meets the minimum DOT specs. Brake hose failures can happen on any bike with synthetic rubber tubed brake hose, its not unique to BMW by any measure. Any brand bike using rubber tubed brake hose is simply using the least expensive brake hose that meets the specs. This has very little to do with it being a BMW problem.

    Synthetic rubber (there are no true rubber brake hose products) tubed hose is a wear item. It is not built to last the life of the bike. So many factors affect brake hose life; sunlight, UV rays, ozone, flexing, tube softening (due to water and brake fluid), pressure cycles, abrasion, twisting, mis-routing, kinking, over-bending, etc. Brake hose should be considered a wear item just like tires, batteries, coolant, etc.

    Standard brake hose is made of three components: the synthetic rubber inner tube, the nylon or polyester braided reinforcement, and the synthetic rubber outer cover. All three layers are bonded together when the raw hose construction is vulcanized. But, over time, the inner tube can soften and loose the bond to the reinforcement. Then a section may come loose and flatten out, acting like a check-valve flap. This can at any time in the life of the hose.

    The only really good quality hose for brake lines is teflon-tubed/stainless steel braided cover construction hose. The real strength of this hose is the tube, not the braiding. Teflon tubed hose simply does not have the issues of material compounding (like standard hose, which is a "mixed component" material), tube irregularities, soft spots, etc. Teflon tubed hose is 100% teflon, not compounded or cured like synthetic rubber. Teflon is one of the strongest inner tube materials to use for hydraulic hose. Synthetic rubber tubed hose is totally dependent on the reinforcement for any pressure/duty cycle life capability. I would never waste one penny on OEM rubber brake hoses unless you are doing a restoration. Otherwise, always replace OEM brake hose with Teflon/SS-braided hose.
    Last edited by ANDYVH; 07-13-2012 at 05:23 PM.
    Woodenshoe to Cheesehead

  7. #7
    not so retired henzilla's Avatar
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    Thanks Andy,

    Must be a reason all the newer bikes have braided SS lines now.

    Have replaced all of our old ones on pre 2004 models we have and several sets for friends with aftermarket with nothing but great feedback...from the owners and the brake system.
    Recently fitted the final set on Helen's 1150R...she noticed major improvement and commented at the first roadside chat stop. She did not know I had done the retrofit so had no preconceived expectations. Just thought I had put fresh pads or something on.

    Yes, fresh OEM rubber hoses will get the job done no doubt, but if you are going to keep the machine and want no issues...the braided lines are it for us.
    Steve Henson
    SABMWRA MOA Club#62's Flat Fixer/ current forum moderator
    It's not the breaths you take, but the moments that take your breath away-D.Dillon/G. Strait

  8. #8
    Day Dreaming ... happy wanderer's Avatar
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    I have to agree here. I put Spiegler braided lines on my 1100RT this past winter and once they were bled properly the difference between rubber lines and teflon braided lines was immediately apparent.

    If you like a truly hard brake lever, great feedback when you pull and twice the lifespan of OEM rubber lines, then teflon braided lines are the way to go.

    I don't see any reason to purchase BMW OEM lines for a retrofit of old brake lines other than keeping the bike "totally original". I doubt an 1100RT is ever going to be a collector's item. Too many of them out there!
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

  9. #9
    Registered User ANDYVH's Avatar
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    What changed in the past few years were DOT regulations on how brake hoses were labelled on the "layline" of the hose. In the past, OEMs could not use SS braided hose because there was no way to print the required DOT info onto the SS braid. Consequently, the better hoses could only be legally installed by the owner, as aftermarket replacement parts, and even then the SS braided hose was for "off highway use only". A product like Parker 919 hose is great for brake hose application. But in its standard form, it could not be labelled per DOT regs, and because it had no clear overlay, the SS braid would easily scratch whatever it contacted.

    Regulations changed, and the hose layline data is applied on a clear overlay on the SS braided cover. Regs met, and the OEMs quickly changed to the better hose product as an update to current products.

    Hose manufacturers could produce a synthetic rubber hose, adequately reinforced to reduce the volumetric expansion properties under pressure (to get the "feel" we seek in quality brake hose), equal to the SS braided hose product. But, no one would buy it because it would look just like the standard brake hose product. And, it would probably cost almost the same as the SS braided product. So there was no market push to produce a better synthetic rubber brake hose.

    Stainless steel/teflon tubed brake hose is not hype at all. It is THE best brake hose you can use on a motorcycle brake system. Period.

    As an aside, some standard brake hoses do seem to last a long time. But usually UV and ozone harden the cover to the point it starts to check/crack. All the cover does is protect the hose reinforcement, which is either nylon or polyester, so it does not compromise the pressure strength of the hose. But, poor maintenance of the brake fluid (like, never flushing it) causes water to build up in the brake system. Surprisingly enough, simple ol water can be a bugger on hoses IF the inner tube does not contain EPDM or similar elastomers to minimize swelling/aging of the inner tube. When the inner tube ages and swells, it looses what little strength it had and it can loosen from the reinforcing bond and collapse. A collapsed inner tube can act like a check valve, produce mushier response, cause dragging brakes, other problems. So again, no reason to use stock OEM non-SS braided hoses.
    Woodenshoe to Cheesehead

  10. #10
    Registered User Bmandiego's Avatar
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    Quote Originally Posted by NavyDad View Post
    These are the same guys who throw six kinds of tantrums if their ten year old bike needs any attention. Go figure.
    Can you list 6 different types of tantrums? I didn't know there were so many...

    ...Joking...
    2000 R1100RT-P

  11. #11
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    Andy, you did a great job explaining some of the issues of SS/Teflon brake lines. Here is a longer discussion of DOT approval of SS lines

    One other issue I have with SS lines is that there have been reports that dirt gets between the SS line and the teflon inner tube and wears a hole in the teflon tube. So, some people recommend having the SS lines coated. Early attempts of the coating the SS lines with PVC didn't work out that well. PVC without heat additives could not handle the heat and cracked and fell off within a couple years. Newer coating have heat resistant additive to make them last longer. Like the one on Earl's . Some people believe that the SS coating doesn't help extend the life for the extra cost.

    I also prefer reusable fittings versus crimped fittings. Although I have a hydraulic crimper, I think the reusable fittings are a better option. It also makes this option available for most people to make up their own hoses. The only expertise you need is the ability to cut the SS lines cleanly.

  12. #12
    Registered User cehlbeck's Avatar
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    Just the other day I replaced the front brake line due to a leak on my 2002 K1200LT. Once done, I found my suspected leak after removing the rubber sheathing. I cut the line open and was amazed at what I found. Notice the difference between what I figured to be "good line" and the area I suspected as being bad or leaking.
    Attached Images Attached Images
    Chris Ehlbeck
    BMWMOA 168990
    Chris & Donna's Motorcycle Journeys

  13. #13
    Registered User Bmandiego's Avatar
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    NIce pics!
    ...and that's why the calipers lock.... That gunk collapses and impedes the flow.
    2000 R1100RT-P

  14. #14
    Pepperfool GSAddict's Avatar
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    Here's pictures of the front line on the 01 F650 I just replaced.
    The inner core is completely rotten and crumbling.
    FYI : The bike had annual fluid replacements.



    '
    Ufda happens..........

    It's all about the details.

  15. #15
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    wow.
    those pics would make me go out and change all my lines on all my bikes over to SS right away; except that all my brake lines already are SS.
    Ride Safe, Ride Lots

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