bmw r1200gs lc rear brake failures

Discussion in 'GS Boxers' started by grace, Oct 31, 2017.

  1. Racegun

    Racegun Single Track Mind!

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    So the quick, fast, maybe not cheap remedy is: Replace the rear M/C if bleeding does not last? Would I need a BMW shop to do this? ( if I had the 911 tool)
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  2. sizzlingbadger

    sizzlingbadger Boxer Fan

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    You won't even need a GS911.
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  3. Lead Wrist

    Lead Wrist Mehr Gelände Weniger Straße

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    If you know what you're doing then no. :deal

    If you don't know what you're doing then obviously yes - brakes are very important safety doohickeys and it should work properly at all times! :deal
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  4. Racegun

    Racegun Single Track Mind!

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    I might have been a bit ambiguous. I was more talking about special tools. Does anyone know how much time is required to R&R the Rear m/c? I am not concerned about the time to bleed the brakes. The difficulty of a job is illuminated by the time it takes to complete said job.
  5. Lead Wrist

    Lead Wrist Mehr Gelände Weniger Straße

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    Same answer applies and no special tools required...

    You should really get Factory Service DVD and familiarize yourself with what's required to do what kind of repair on LC Boxer GS/As - it'd help you a lot with the questions you're asking... :deal
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  6. JimsBeemer

    JimsBeemer 2017 R1200GSA, 2016 R1200RT Supporter

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    There have been a couple of recent post regarding the use of the linked brake system vs. the rear pedal - such as

    Regardless of one's style/use/opinion regarding using the rear pedal vs linked brakes, as relates to the fading-pedal issue that is the topic of this thread, it is important to understand that the linked brakes, and the hilllstart assist systems BYPASS the rear brake master cylinder. When I had ZERO rear pedal, I still had rear brake with the linked brake and hill start. And as far as I understand (and I wish someone could post a hydraulic schematic for the brake system - my Haynes manual does not include one) the linked brake and hill start feature use the ABS pump to actuate the rear brake. So this seems to clearly isolate the problem to the MC at the rear brake pedal.

    This is my understanding - but if anyone has information to show otherwise, I'd love to hear it. And as I said, it would be awesome if someone could post a schematic of the complete braking system hydraulics if such a thing exists.

    Jim
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  7. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    Half an hour at most. It is a simple enough job.
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  8. Racegun

    Racegun Single Track Mind!

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    Jim, if one has a rear brake that gets spongy multiple times, what the chance that if they simply replace it the problem will go away? Also, do we have a choice of what brand of M/C? ( one brand being better etc)...

    Are some years of the wet-head less likely to have this problem?

    thx!
  9. Callisto224

    Callisto224 Long timer Supporter

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    Pretty sure it didn't show up until the 2018 and later model years.
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  10. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    I would be guessing, but the issue wasn't present in the early Wethead, so if you used an early one, you should be good to go.
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  11. JimsBeemer

    JimsBeemer 2017 R1200GSA, 2016 R1200RT Supporter

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    My 2017 definitely has the issue, fwiw.
  12. adam71

    adam71 Been here awhile Supporter

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    My 2016 had the brake issue. So, I can speak from my own experience regarding that particular year having a spongy rear brake.

    At one point on day 1 of a 4 day road trip about a year and a half ago, I lost all pressure in my rear brake. I noticed it during a downhill portion of eastbound Ebbetts Pass (South of Lake Tahoe are). Their was gravel in some of the turns, and I attempted to control my speed at times by using the just the rear brake. The pedal pushed all the way to the stopper and nothing happened. Not a great feeling!! I had to be careful using only the front brake and engine to slow me down the steep descent.

    The following day I was able to have the rear brake bled by the BMW dealer in Chico. It fixed the problem for a few months, but it eventually reared it’s ugly head.

    I just learned to live with it. Until @18415 convinced me to swap it with a Brembo.

    Tomorrow’s 400 mile loop will include some dirt. I’ll keep this thread posted!!
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  13. jdub

    jdub Dawg bytes reel gud Supporter

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    My 2014 GS has also always had the rear brake problem. Never to the point of complete failure, but it gets soft in between bleedings. Never experienced this on any other bike.
  14. TrailRoad

    TrailRoad bigger playground

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    This is different. I had a 2015 I put 32k miles on. The rear and front brakes would occasionally get squishy (tech term). A good bleed and/fluid change would bring them back to life. At least for 5-6k miles.

    Recently picked up a 17.5 Rallye with 7k on it. When I got it brakes were fine. I’ve put about 1k on it so far and was out a week or so ago for a day ride (including 150 miles off road) any 3/4 through the ride I realized I had no back brake. No pressure at all. Thought I had a leak or got low on fluid some how.

    Everything looked good- so I just bleed the brakes and put new fluid in. So far good on the test ride, will do a longer day ride soon. But I think there might be a brembo in my future if this continues.
  15. bmw_rider

    bmw_rider Been here awhile

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    My 2017 1200GS had the problem over & over & over for 42,000 kms and then i traded it on a 2019 1250GS and the same rear brake issue continued till now at 34,000 kms.
    What a fuck up on BMW's part and still no fix that lasts.
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  16. Racegun

    Racegun Single Track Mind!

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    MAN THAT SUCKS!!! BMW CERTAINLY IS NOT HELPING ITSELF AT ALL!! BMW MOTORRAD MUST REALIZE HOW STIFF THE COMPETITION IS. How could they not? That can mean only 2 things. They do NOT care or DO NOT KNOW what to do! And the fact that this has been happening for years! DAMNIT ANYWAY! Of all the systems, brakes are the absolute most important !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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  17. adam71

    adam71 Been here awhile Supporter

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    The verdict is in:

    The new Brembo rear MC is awesome!!

    Thanks again to @18415 for the idea/research/installation!!
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  18. Racegun

    Racegun Single Track Mind!

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    There ya go! Problem solved! Thank You!
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  19. Lead Wrist

    Lead Wrist Mehr Gelände Weniger Straße

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    Great news for anyone who may experience the issues w rear brakes - thanks to both of you... :clap

    So reader's digest version: replace GS's master cyl w Brembo off of '16 S1000XR (p# 10477620), add GS's actuating rod (p# 34 31 7 692 792), both sourced at BMW dealer, add few screws, bleed the brake after install and voila, all problems solved... :D

    Pic of needed components from few pages back:

    [​IMG]
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  20. adam71

    adam71 Been here awhile Supporter

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    @Lead Wrist

    thanks for summarizing that and putting all the part numbers out there!

    @18415

    I can’t thank you enough for all the work you’ve done on my bike! Much appreciated!
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