LC front brake caliper rebuild?

Discussion in 'GS Boxers' started by marchyman, Jun 19, 2019.

  1. marchyman

    marchyman DR and GS Supporter

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    Does anyone have experience with a a front brake caliper rebuild on an LC bike?

    I feel/hear a click when slowly pulling of the front brake lever of my '13 GS wethead. If I put fingers on the right brake caliper I can feel the click. I suspect the piston is sticking or I've a bad seal or something like that. In searching the net I've not found anyone who's re-built LC front brakes nor have I found a front brake rebuild kit. Perhaps my search-fu is weak. The beemer shop does have a kit but their site claims it is for '05-'12 bikes.

    I'd appreciate hearing from anyone who has torn into their front caliper. Any issues or words of wisdom?
    #1
  2. attila_66

    attila_66 Adventurer

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    34118556200 This part no is piston with seals. No.11 on the picture.
    upload_2019-6-20_4-47-2.png
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  3. b_rubenstein

    b_rubenstein Been here awhile

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    Keep in mind that these brakes have fixed calipers and a floating rotor The click is probably the rotor shifting. My '17 makes the same click when I pull the front brake lever when the bike isn't running or moving.
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  4. marchyman

    marchyman DR and GS Supporter

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    Thanks. Except for the cost. $166.51

    I think I'll wait until I put things apart before I order the entire kit. I may only need new seals. Assuming I can find a place to buy seals, only.

    I found this video on rebuilding a similar Brembo caliper.



    I don't think that is the issue but I'll be sure to check again. For one think I only get the click from the right side and I certainly can feel it in the brake lever. when it happens.
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  5. LAFS

    LAFS Long timer

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    Have you looked at the switch on your brake handle? You know that little plunger in the handle? It could be that. Also have you checked the cable and the retaining end of the cable where it goes into the slot of the handle?
    #5
  6. KHud

    KHud Survivor

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    This guy specializes in Ducati bikes, but there is crossover in Brembo parts. Email him and he may have seals and pistons for your caliper. It is quite possible you can just clean the caliper and solve the problem. Remove the caliper from the bike; put a spacer between the pistons to prevent them from coming out; use compressed air to force the pistons out as far as the spacer allows; clean with brake fluid and an old tooth brush. If the the pistons have build-up that the tooth brush will not remove then use fine steel wool.
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  7. b_rubenstein

    b_rubenstein Been here awhile

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    To get a metallic click sound, something metallic has to hit something else metallic. About the only way to get a metallic click from one of those calipers is to have loose caliper mounting bolts, or a pad shim moving. The only moving parts in the caliper are the pistons and typically sealed with a square section O-Ring in their bore, so there is no metal to metal moving parts in the caliper to cause a click.

    It's obvious that you've decided its a problem with a caliper based upon having a rather tenuous understanding of how the front brakes work and what parts do what. Have fun.
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  8. LAFS

    LAFS Long timer

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    So you do know these are floating rotors right?

    Your metal statement is not true at all as a rotor can make noise with no brake applied if the buttons that float loosen up over time. It can also make noise when the brakes grab a loose floating rotor to a stop.
    #8
  9. marchyman

    marchyman DR and GS Supporter

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    Did I say metalic? I suspect I've got a piston hanging up on the dust seal and breaking free when enough pressure is applied.
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  10. LAFS

    LAFS Long timer

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    Sometimes a good cleaning is all that is needed. That is where I would start. I do mine every time I change tires. They will build a ridge but I am not sure that would cause a vibration. In the last pic you see the pin the pads slide on, that can become very caked up. I sand it with 200-400 grit paper and use a high temp copper grease on all the slide points and that pin. Liberal use of brake cleaner is called for on this project.

    [​IMG]

    [​IMG]

    [​IMG]
    #10
  11. marchyman

    marchyman DR and GS Supporter

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    That is what I'm hoping. If it is something like crud built up on one of the pistons a cleaning may be all that is needed. Or maybe it not a piston, but a brake pad hanging up on something. In any case I'm not going to disconnect the caliper from the brake lines until I know I have to, if for no other reason that getting all the air out of calipers that have been drained can be such a pain. My asking for pointers is a boy scout thing: be prepared.

    I will also be replacing a rear disk... it will be at the specified minumum just about the time the bike is due for a service. Seems I get about 50K miles per rear rotor. Got that on my '05. Am getting that on my '13. Pretty linear wear of about 0.01 mm/1000 miles.
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  12. antariusjp

    antariusjp Large Title Here

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    Just remember most brake cleaner is, believe it or not, not good for rubber parts - like the seals you're trying to protect. Just regular dish soap, warm water and a soft tooth brush will work just fine when you clean the pistons.
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  13. LAFS

    LAFS Long timer

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    Brake cleaner will not affect brake piston seals.

    I was told that strait from a Brembo car brake rep many years ago.

    Good thing as I been cleaning brake calipers on cars and motorcycles for 40 years with brake cleaner and never had a piston seal fail.

    As a matter of fact I have never had a caliper fail in any car or motorcycle I have ever owned.

    Of course I run summer and winter wheel/tires on my car so when I swap wheels the calipers get cleaned so been doing that for 25 years or so.

    I guess preventive maintenance pays off.
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  14. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    Agreed. I question whether this is a caliper failure, or something else?
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  15. marchyman

    marchyman DR and GS Supporter

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    It is not a failure, more of an annoyance. And yes, it could be something else. As noted above I simply want to be prepared should it turn out that I need to replace seals, etc.
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