Rear caliper issues, R1150GS

Discussion in 'GS Boxers' started by kbroderick, Apr 7, 2014.

  1. kbroderick

    kbroderick Long timer

    Joined:
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    Red Lodge, Montana
    So I went to swap my rear brake pads last week, and I found something that seems a bit odd: I don't have a circlip on the pin to keep it in place, yet I still cannot tap it out. I tried gently tapping it from each side (figuring that it might be stuck due to grit, grime, or other GS-riding-related issues), and it has some freedom to move, but not much.

    So...

    a) has anyone ever seen this before?
    b) any thoughts on attempting to repair it? I'm leaning towards sourcing a used, lower-mileage caliper in good condition, as I'm inclined to assume that the main sliding pins are also in rough shape and don't appear to be available as repair parts.

    [​IMG]

    (pin is upper-left in photo; from other angles, the indent for the circlip is visible, but there's no circlip in it).
    #1
  2. GS Addict

    GS Addict Pepperfool

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    It needs to driven with a small pin punch for the side shown towards the disc.
    It more than likely frozen in and will need penetrating oil to loosen.
    If you are replacing the pads contamination won't much matter, just clean the disc off thoroughly.
    New pins are available in a service kit.
    You also get the missing circlip.

    <table cellpadding="0" cellspacing="0"><tbody><tr style="vertical-align: middle; font-family: Arial; font-size: 11px; background-color: #fff;"><td style="width: 85px; border-left: solid 1px #ddd; border-bottom: solid 1px #ccc; font-weight: bold;" align="left">34 21 2 330 313</td><td style="width: 235px; border-left: solid 1px #ddd; border-bottom: solid 1px #ccc; font-family: Arial Narrow;" align="left"> SET MOUNTING PARTS</td><td style="width: 30px; border-left: solid 1px #ddd; border-bottom: solid 1px #ccc;" align="right">0.03 </td><td style="width: 35px; border-left: solid 1px #ddd; border-bottom: solid 1px #ccc;" align="right">1 </td><td style="border-left: solid 1px #ddd; border-bottom: solid 1px #ccc; width: 100px;" align="right">$21.19[​IMG]</td></tr><tr style="background-color: #fff;"><td colspan="6" style="border-bottom: solid 1px #666;"><table style="width: 510px; font-size: 11px;" cellpadding="0" cellspacing="3"><tbody><tr><td>[​IMG] </td></tr></tbody></table></td></tr></tbody></table>
    #2
  3. Mike Ryder

    Mike Ryder Kriegerkuh

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    has some one peened the clip end?
    Too muddy to tell from here.
    #3
  4. MIXR

    MIXR Been here awhile

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    Put the tools away and clean the damn bike first, then you might see what the deal is.

    The pin should have a circlip as you suggest. Not unusual for that to drop off or get knocked off, particularly if it's old and has lost some spring.

    It's a safety device. The pin is held in by a force-fit 'olive' on the other end of the pin. Like a 'bulb' as per the photo kindly posted previously.

    Use a pin-punch or similar to gently tap the pin out towards the inside of the wheel, so sit next to the wheel and tap inwards. It will just drop to the ground, or on to a clean rag.

    Install is the reverse. You'll know it's seated when the olive is engaged and the circlip groove is visible with clearance for the circlip. Lubricate the slide pin with an appropriate brake grease and wipe up the excess. I usually just clean mine with some scotchbrite and use a high-temp grease smear so the pads don't stick on the slide pin.
    #4
  5. kbroderick

    kbroderick Long timer

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    Not sure if I should admit this or not, but I did actually spend a couple of minutes with a grunge brush and and old toothbrush earlier in the process. My first thought was that I wasn't seeing the circlip because it was under the dried mud.

    I tried tapping it with a pin punch, both gently and not quite so gently. I didn't go so far as to ream on it, but I kinda figured that would've been a bad idea on a number of levels (not the least of which being that I didn't have either wheel on the bike at the time). Thanks for the clarification that the 'olive' is actually the primary retaining device.

    Thanks to all for the responses. I'll have to order the repair kit and give the retaining pin another shot before giving up on the caliper.

    Thanks,
    Kevin
    #5
  6. mouthfulloflake

    mouthfulloflake Not afraid

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    My circlip has been missing for the last 2 brake pad changes... 10K + miles, I keep forgetting to find one at the hardware store.

    the rubber "olive" on the other end does a fine job of holding the pin in place without the clip.
    it takes a good whack from a block of wood or mallet and a skinny drift to get the pin movement started.
    #6
  7. biometrics

    biometrics Been here awhile

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    Good Luck on finding that circlip at a hardware store. I took my "clean" pin to several local and big box hardware stores and couldn't find one that would fit. :cry

    I ended up getting one that was close (but slightly too large) and then sanding it down so it would fit in the groove, and crimping it slightly to keep it on the pin. Not happy with the result, and a new pin kit has been ordered. :wave
    #7
  8. mouthfulloflake

    mouthfulloflake Not afraid

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    I am sure mcmastercarr has something that will fit.

    a bag of qty 50 in stainless steel for shaft dia anywhere from 1-8mm is under $10
    #8
  9. Mugwest

    Mugwest .

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    I lost the orig clip and discovered the pin had indeed moved in toward the spokes. A vision of what that would mean got me to Home Depot PDQ where i found the same oddball assortment as you. Bought the 2 nearest sizes and made one of them work by crimping. Dabbed some green marker paint on it to remind me to get a proper clip.

    That was 3 years ago :wave
    #9
  10. SourKraut

    SourKraut Long timer

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    The original circlip from the pin on mine is in my shop. Somewhere. :bluduh

    After searching high and low for an hour or more I broke down and ordered the kit.
    #10
  11. mouthfulloflake

    mouthfulloflake Not afraid

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    OK I measured the pin on the brembo caliper on my 1995 r1100gs today.

    where the circlip goes, the pin is 4mm, with the recessed groove being something less than 3.6mm ( the knife edge of my vernier had not enough taper to measure it perfectly)


    so basically, the E clip needs to mount to a shaft less than 3.6mm

    mcmastercarr part number:

    http://www.mcmaster.com/#98543a103/=rgbm2j


    under $4 for 100 of them, fits a 3.2mm dia groove, that is probably smaller than this groove which should put a good 'bind' on it.
    #11
  12. GS Addict

    GS Addict Pepperfool

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    Strip some cat 5 or phone solid copper (22 or 24ga) and wrap in pin slot and spin with pliers. Some safety until the clip arrives.
    #12
  13. s1marks

    s1marks Mercedes

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    I took my pin into ACE Hardware and found a clip that fit. Home Depot or Lowes don't typically carry the variety of stuff you need in these situations. If you want a bolt or a washer of a certain size, ACE Hardware is usually your place if you want one quick. Just don't buy all your nuts and bolts form there or your bike will be worth less than the sum of the nuts and bolt you use to hold it together!

    S1
    #13