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  1. #1
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    Aligning caliper to disc (Shimano M988)

    Hey guys, is there a trick to snugging up the caliper bolts on the M988? I have it perfectly lined up but when I apply a bit more torque on the bolts the caliper shifts with the turn of the bolt. I can't seem to hold the caliper in place while tightening it up. I think the manual called for 4 inch pounds and that's damn near finger tight if I'm not mistaken. I wish I had a small torque wrench but I don't. I think I'm more than finger tight right now. This is for the front caliper.
    Is something like blue thread locker advisable? I'd hate to have the caliper shift on me during a good ride.

    Edit: I just did a quick test run around the block with hard front braking and now I'm getting a tiny bit of disc rub.

    Thanks.

    Edit edit: I fixed the problem. I threw on the OEM bolts with the washers and it had enough gripping power to keep the caliper from moving. I switched them out initially to Ti bolts just because. I'll stick to the OEM bolts for now unless I can find thin washers for the Ti bolts.
    Last edited by jizzim; 04-20-2013 at 09:07 AM.

  2. #2
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    According to the tech docs for the M985 (shouldn't be any different for yours), the torque should be 6 - 8 Nm {53 - 69 in. lbs.}. You may have to try and hold the caliper in place while slightly torquing the bolts down to ensure the caliper doesn't shift. Just out of curiosity, do your bolts have washers on them?

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  3. #3
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    I stand corrected. Misread the damn instructions on the torque spec. Yep, the factory bolts did have the washers on them with dried blue thread locker. I was just trying to be one of the cool kids and use the Ti bolts.
    With the factory bolts on I SLOWLY torqued each bolt alternating between the two and getting a good grip on the caliper. I think all is well now.

  4. #4
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    In the future, oiling the washer before tightening the bolt will help keep it from walking the adapter/caliper off where you want it.

  5. #5
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    loose the bolts press the lever keep it tight, tight the bolts you are done

  6. #6
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    For me I have had to use a rubber band to hold the brake lever tight on the disc, and then I tighten each bolt a little at a time until snug and then hold the caliper to keep it from walking for the final tightening.

  7. #7
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    Quote Originally Posted by firebike7 View Post
    For me I have had to use a rubber band to hold the brake lever tight on the disc, and then I tighten each bolt a little at a time until snug and then hold the caliper to keep it from walking for the final tightening.
    you explain it better with this method is almost imposible that it gets in the wrong position the only way is that the rotor is bend or a mistake by tightening the bolts

  8. #8
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    Quote Originally Posted by CRchris1996 View Post
    loose the bolts press the lever keep it tight, tight the bolts you are done
    No. Not the proper way to do it. Yes, I'm aware its what Avid recommends for their CPS system and it does not properly set up the caliper. Watch the videos on Hope's site on how to center a caliper and then how to centralize pistons. Its a two step process to do it right and get the most power out of your brakes.

    I use spark plug feeler gauges to center the caliper over the rotor and once I get the gap equal on both sides (without the pads in), I leave the feeler gauge in there while I tighten the bolts. Flawless setup every time.
    Alcohol may lead nowhere, but it sure is the scenic route!

  9. #9
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    Quote Originally Posted by CRchris1996 View Post
    you explain it better with this method is almost imposible that it gets in the wrong position the only way is that the rotor is bend or a mistake by tightening the bolts
    Or you have a sticky piston, or a slow piston, or a misaligned/stuck piston . . . worse if you have more than 2-POT brakes.
    Alcohol may lead nowhere, but it sure is the scenic route!

  10. #10
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    Quote Originally Posted by CRchris1996 View Post
    loose the bolts press the lever keep it tight, tight the bolts you are done
    I tried this too but still kept on getting light rubbing.

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