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Thread: More on BMW brake line failures

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  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
    Nickname: Droid
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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.

  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
    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

  9. #9
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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.

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