rear brake draging

Discussion in 'Dyna Models' started by Dswartz, May 17, 2011.

  1. Dswartz

    Dswartz Active Member

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    I am working on the 20,000 service for my '02 superglide which means repacking the rear fork bearings. I have never removed the rear wheel myself so this is all a relatively new experience. For the most part it all went well but when I reinstalled the rear brake caliper it seems like there is extra drag on the brake when I rotate the wheel. I bled the system and everything is working it just seems like the pads are no longer in alignment. I know there should be some drag on disc brakes but this is more than before. Is there a simple way to realign the pads or should I just ride it as is. The wheel still turns and the brakes still lock up when applied. Is it safe to have some extra drag?
     
  2. glider

    glider Veteran Member

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    The drag could be a result of the caliper pistons needing a cleaning or the caliper not in the proper position. Check them both out to determine the cause of the brake hang up.

    Make sure the caliper isn't hung up in the mount.
     
  3. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Glider has given you some good advise. You need to make sure the piston isn't hanging up and not retracting, and if the caliper body is hanging up on something the fixed side pad may be rubbing the brake disk. If you run it with the pads contacting the disk you have the risk of overheating may warp the rotor.
     
  4. Jack Klarich

    Jack Klarich Expert Member

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    Check for proper belt adjustment also, if the rear wheel is cocked it will cause you problems, check and adjust brake pedal free travel also:s
     
  5. Dswartz

    Dswartz Active Member

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    I'm still having a tough time. I pryed both pistons back and took the pads out to have a look at them. Both pads seem to be in good shape with plenty of pad left on them. They also appear to be wearing evenly. The pistons seem to be moving freely. I'm almost thinking I might have gotten some brake dust or something on the pads. I'm considering purchasing some new pads and seeing if that helps. Like I said the wheel is still turning ok but I can definately hear a metallic dragging noise.

    I'm also pretty sure the alignment is correct. I checked it several times while I was putting everything together.

    Also with the position of the caliper I'm not aware of a way to adjust it. There doesn't seem to be any way for it to be out of alignment.
     
  6. Jack Klarich

    Jack Klarich Expert Member

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    Check for residual pressure in the caliper, crack the bleeder screw loose after pumping the brakes up, you should not have a steady stream of fluid with no pressure on the pedal
     
  7. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    If you retracted the pistons some to make it easier to reinstall the wheel/rotor in the caliper and did not clean the pistons before doing this, you probably have some trash in the caliper at the seals that is not letting the piston(s) retract slightly after you release the brake pedal. You can try removing the wheel again, carefully cleaning the existing exposed part of the pistons, carefully apply a little bit of brake pedal to extend the pistons a bit, re-cleaning and repeating this a couple of times so 1/8" or more of piston surface has been extended and cleaned. Then retract the pistons so that you can get the rotor back up between the pads. Try that and see if it has freed up the pistons to retract slightly after you let up on the pedal.

    If this does not work, you may be in for rebuilding the caliper. If you have to do this, do not scrimp on the rebuild kits that include new pistons. Worth doing it right!

    TQ
     
  8. glider

    glider Veteran Member

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  9. Dswartz

    Dswartz Active Member

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    Wow, that was frustrating. After ruling out all other possibilities I eventually took the wheel off again which I really didn't want to do but I knew I had to. I followed TQ's advice and cleaned the pistons really well. I also worked them back and forth a few times just to make certain that nothing was binding and everything was functioning properly. When I finally put everything back together it seemed to be working fine. Thanks to everybody for the good advice. Once again this forum has come to the rescue!

    As frustrating as it was to deal with the brake issue I still learned alot yesterday when I was working on it. I'm still rather young compared to most of the guys on this forum and apparently still have alot to learn. I ended up spending most of the day working on the bike. It seems to take me forever when I do something for the first time. I dont want to screw anything up so I work really really slow and think about each step. The good news is the second time I pulled the wheel off I did it rather quickly and easily. So if nothing else this problem ended up giving me some good practice working on the bike and becoming more familiar with it. Besides it rained all day yesterday so if I cant go out and ride I guess the next best thing is to wrench on it right?
     
  10. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Glad it worked out. Just make a mental note for next time that the pistons need to be cleaned BEFORE retracting them into the caliper. Will save all the frustrations that you had this time.

    TQ