Rear Brake Linkage Nut

Discussion in 'KTM 950/990' started by advhound, Sep 14, 2019.

  1. advhound

    advhound Been here awhile

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    Hey all, see attached picture. I am having issues with my '07 990 adventure rear brake not maintain pressure reliably. Even pumping does not help. I found that this nut is slipping since the shop last touched my bike when I didn't have time to work on it . On the parts diagram, it shows part 0934060003 HEXAGONAL NUT DIN0934-M 6 and it looks like there are qty: 2 so they lock against each other. Then I looked at other 990 rear brake push rod linkage pictures on images.google.com and most only have 1 nut. What's the right way and how should I resolve my issue?

    Attached Files:

    #1
  2. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    Two nuts, one above and one below.

    20190914_103056.jpg
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  3. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    But that won't have anything to do with the brake not holding pressure. What was the issue that you took the bike to the shop? And what did they supposedly do?
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  4. advhound

    advhound Been here awhile

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    Well it might have something to do with it not holding pressure because the nut is slipping to where not enough fluid is being pushed to activate the brakes. With that, your point is well taken. I am not positive what the issue is. The shop completely rebuilt the rear brake as those brembo's calipers are notorious seizing, or so I was told. See 2nd picture attached. I am going to buy 2 additional nuts and set 2 above to lock against each other and replace the missing one below and report back what I find. It is interesting that the adjustment on the plunger bolt seems to be just about maxed out. The brake fluid level is okay. There is always a possibility that there is air in the brick fluid and needs to be bled. Any other thoughts? MVIMG_20190914_110924.jpg
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  5. Boatman

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    Yep,,,, the plunger might not be returning far enough. The hole where the clevis pin attaches the lever to the clevis is elongated. You should be able to depress the pedal a couple mm before the plunger starts moving.

    I'd really be talking to the service department about this. Without the second nut it's entirely possible in a certain situation for the plunger to come out of the clevis leaving you with no rear brake at all. I wouldn't wait to order another M6 nut and just get one at a hardware store until the OEM arrives.

    I've owned many bikes with Brembo brakes over the past 40+ years of riding,,,, can't think of one that seized. Not to say it doesn't happen, but I don't think "notorious" is correct.
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  6. DirtyADV

    DirtyADV Long timer

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    I would avoid that shop.

    Sounds like they are full of shit.

    Sadly had several bad experiences with "authorized" service on both bikes and cars.

    /Johan
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  7. advhound

    advhound Been here awhile

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    Got some nylon locking nuts to make sure they don't get lost again. I checked the pin hole and I don't believe it looks elongated. I am hitting the limit when depressing the pedal without a huge amount of force. Is that normal? See pic and video
    MVIMG_20190914_125613.jpg
    ezgif.com-video-to-gif.gif
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  8. NKL

    NKL Been here awhile

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    No, that is not normal. Either air in the system or the pistons are backing out too much when you release, can you see what the pistons are doing as you move the brake leaver
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  9. advhound

    advhound Been here awhile

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    From looking at the pistons and pads with the rear wheel on, I can see them actuating what seems like a normal amount and then returning. Nothing looks out of place. Do I need to take the rear wheel and pads off to have a proper look?

    What does the bleeding process look like on the KTM 990? I have been told that it is a "reverse bleed". Meaning you take the lid off the master cylinder, put brake fluid in with a syringe, and then remove excess from the nipple on the brake caliper?

    I just took it for a ride and at first rear brake after a while, there is virtually no braking power. After pumping 3-5x, the brake engages enough to actuate ABS.
    #9
  10. Boatman

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    The clevis hole is elongated. It may not look like it to the naked eye but it is. Without touching the pedal you should be able to move the clevis up and down.

    From your video.... there is some bleeding that needs to be done.

    Reverse bleeding is forcing fluid in from the bleeder on the caliper with a syringe and then sucking the excess out of the master before it over flows. Yes with the cover off.

    Regular bleeding is filling the master. Then pump up the pedal and opening the bleeder on the caliper . Do this until no air comes out and you have a stiff pedal.
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  11. Boatman

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    Still can't believe a service department would give the bike back to you like that.
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  12. Salzig

    Salzig Long timer

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    Looks just like the problem I had on mine.
    I pumped the pedal after refitting the rear wheel and something didn't feel right.
    Turned out that the piston sort of seized in the pump. I could get just a little piston movement and it didn't came back to the released position.
    Disassembled, cleaned and reassembled and all was well.
    Ordered a new pump instead of a rebuild kit cause it is 12 years old and also the sight glass was protruding since a few years.
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  13. roookie1

    roookie1 Been here awhile

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    Totally agree, the Brembos are fine. More than 106000 km, never rebuilt, no problems..
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  14. Boatman

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    In the first couple seconds I show the free play in the clevis and then I depress the pedal to show how much movement you should expect.

    I guess its unclear to me if the shop rebuilt the master along with the caliper.
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  15. DirtyADV

    DirtyADV Long timer

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    Had big issues on my dad's bike bleeding rear brake, tried everything and could not get it good enough.

    Turned out bleed nipple was clogged, after having that out and cleaning it was possible to bleed.

    Can be a high spot causing issues since caliper is lower then highest point on hose.

    Unhooking caliper and bringing that up can help, zipty something suitable thick in between pads to not push pistons to far out while bleeding.

    /Johan
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  16. advhound

    advhound Been here awhile

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    When you say the piston seized in the pump, you are talking about the master cylinder, right?
    And you ordered a whole new Main Brake Cylinder Complete part # 60013060200?
    Another solution is to order the Repair Kit Piston part number 60013061000, right? What is the process to install this repair kit? Do I have to drain the brake fluid?
    And just to clarify, none of your issue was related to the rear caliper? Thanks! Just trying to understand what I am in for!
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  17. Whodatschrome

    Whodatschrome Long timer

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    Interesting...mine are the same way. The doc never mentioned it was a problem though.
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  18. Salzig

    Salzig Long timer

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    Yes, the problem was on the master cylinder. Part # is correct, 190€ ouch!
    To remove the pump piston you have to back up the adjusting rod, remove the rubber and watch out for the washer that will fall on the floor.
    Then there is a circlip holding the piston in.
    No need to drain the fluid, I only emptied the reservoir.
    Pretty simple, I did it with the pump still on the bike.
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  19. advhound

    advhound Been here awhile

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    Hey all, I fixed the issue with my rear brake! I reverse bled the rear brake line and it works great now. Thanks for your help!
    Took awhile because the caliper bleed nipple sheared off when loosening it initially, so had to order one from my local shop and it took 2 weeks
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