Announcement

Collapse
No announcement yet.

Brake pulsating at lever

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Brake pulsating at lever

    What are the other causes apart from warped rotors?
    I believe the wheel bearings are fine too.

    Could caliper problem cause it?

    These are Kawasaki with the plastic inserts inside the piston that push against the pad... Maybe if they're worn at an angle or something? First time I have come across it like this.

    The rotors are brand new EBC so I know they're straight!
    1980 GS1000G - Sold
    1978 GS1000E - Finished!
    1980 GS550E - Fixed & given to a friend
    1983 GS750ES Special - Sold
    2009 KLR 650 - Sold - gone to TX!
    1982 GS1100G - Rebuilt and finished. - Sold
    2009 TE610 - Dual Sporting around dreaming of Dakar.....

    www.parasiticsanalytics.com

    TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

    #2
    did you bed in new pads with the new rotors?

    Comment


      #3
      Originally posted by posplayr View Post
      did you bed in new pads with the new rotors?
      EBC HH pads FA 129's from memory. Brand new. No especially break in reqd that I know of. The pulse has got a bit more pronounced with use....
      1980 GS1000G - Sold
      1978 GS1000E - Finished!
      1980 GS550E - Fixed & given to a friend
      1983 GS750ES Special - Sold
      2009 KLR 650 - Sold - gone to TX!
      1982 GS1100G - Rebuilt and finished. - Sold
      2009 TE610 - Dual Sporting around dreaming of Dakar.....

      www.parasiticsanalytics.com

      TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

      Comment


        #4
        Dan,
        Is that your old G?

        Any spacer behind the disc? Sounds like something is not sittting down flush like it should.
        Ed

        To measure is to know.

        Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

        Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

        Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

        KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

        Comment


          #5
          Try getting them hot, by dragging them lightly for 1/2 mile or so, then braking HARD,. Do not come to a stop, just go from around 60 down to 20mph or so. Speed back up and do it again,
          several times.





          Sorry, these are car sites, but the science is the same.
          Last edited by tkent02; 05-06-2010, 09:27 AM.


          Life is too short to ride an L.

          Comment


            #6
            Well, a pulse in the lever has to come from runout somewhere...

            Either a warped rotor, or something that rotates that's not seated. I don't see how anything stationary (ie, all caliper components) could pulse since it's stationary.

            Hmmm.....

            Comment


              #7
              Originally posted by kirkn View Post
              Well, a pulse in the lever has to come from runout somewhere...

              Either a warped rotor, or something that rotates that's not seated. I don't see how anything stationary (ie, all caliper components) could pulse since it's stationary.

              Hmmm.....
              No, it doesn't.
              Read the stuff I put up.
              Here's another, there are many more.
              Powerbrake: the World Leaders in Brake Upgrades for 4x4 Vehicles
              Last edited by tkent02; 05-06-2010, 11:29 AM.


              Life is too short to ride an L.

              Comment


                #8
                Originally posted by tkent02 View Post
                No, it doesn't.
                Read the stuff I put up.
                I did, and it makes a truck load of sense. To be honest, I cant say as I have ever followed these instructions, but I will certainly now.

                It also makes me wonder if the guys at Car & Driver, or Road & Track follow these precautions when they test these new supercars and then bitch about their braking. I just read a piece they did not too long ago where they ran a hot lap around Virginia (Is it Infinion raceway?) and managed to total a BRAND NEW high performance package 370Z into the walls because of "horrible brake fade"

                Comment


                  #9
                  Originally posted by TheCafeKid View Post
                  I did, and it makes a truck load of sense. To be honest, I cant say as I have ever followed these instructions, but I will certainly now.

                  It also makes me wonder if the guys at Car & Driver, or Road & Track follow these precautions when they test these new supercars and then bitch about their braking. I just read a piece they did not too long ago where they ran a hot lap around Virginia (Is it Infinion raceway?) and managed to total a BRAND NEW high performance package 370Z into the walls because of "horrible brake fade"
                  Could be, dunno. Maybe the car had sh:tty brakes, but a real driver would learn this before crashing.
                  Anyway I have been able to fix shaky brakes on a lot of cars and bikes by doing this proper bedding procedure, from my Mom's Jeep that went through about six sets of rotors, several high mileage BMWs I bought, couple Volvos, my Ford truck, several other cars and a lot of bikes too.

                  I don't understand why most brake pad manufacturers don't include pad specific bedding in instructions with every set of pads, probably the same fear of liability that makes them recommend riding a new bike slowly instead of breaking it in correctly.
                  Last edited by tkent02; 05-06-2010, 11:41 AM.


                  Life is too short to ride an L.

                  Comment


                    #10
                    You can always eliminate runout as the source of the problem with a dial indicator.
                    De-stinking Penelope http://thegsresources.com/_forum/sho...d.php?t=179245

                    http://www.thegsresources.com/_forum...35#post1625535

                    Comment


                      #11
                      Originally posted by tkent02 View Post
                      No, it doesn't.
                      Read the stuff I put up.
                      Here's another, there are many more.
                      http://www.powerbrake.co.za/download..._01_judder.pdf
                      Now that's very interesting. I've heard of it, but never the statements about 0.0004" being detectable to the driver, and 0.001" being annoying.

                      And, in fact, I follow that bedding-in procedure every time I replace pads, car or bike, but I never knew all that reasoning behind it.


                      But, I still think I was on the right track - the pulsing is being caused by some component that's rotating (in this case, uneven deposits on the rotor) rather than any stationary component - pads or inserts, etc.

                      Kirk

                      Comment


                        #12
                        Originally posted by kirkn View Post


                        But, I still think I was on the right track - the pulsing is being caused by some component that's rotating (in this case, uneven deposits on the rotor) rather than any stationary component - pads or inserts, etc.

                        Kirk
                        Yes, absolutely correct.


                        Life is too short to ride an L.

                        Comment


                          #13
                          Pulsing

                          The pulsing can be attributed one or two rotors being untrue. I ran into this on my 1100E a few years ago and took the wheel to a friend's machine shop, where he straight-edged them to be sure.

                          A friend of mine has a ZZR1200 that had the same problem. I don't know if it's proper, but he used a series of polishing paper (not really paper) between the pads and rotors. He bled off some hydraulic pressure, placed the sticky-backed paper, lightly tapped the lever, and rode the bike up and down his street without applying the front brake. It worked.

                          Comment


                            #14
                            Had the same exact pulsation on my 1100. It's warped rotor(s) plain and simple. I do machining by trade, made a spacial arbor stub to hold the GS rotors, and skim cut until I got the rotors to within the spec runout (I beleive it was .012" ) ? Mine were warped pretty bad, got them right at the spec limit, and pulsation was gone.

                            Comment


                              #15
                              Originally posted by Road_Clam View Post
                              Had the same exact pulsation on my 1100. It's warped rotor(s) plain and simple. I do machining by trade, made a spacial arbor stub to hold the GS rotors, and skim cut until I got the rotors to within the spec runout (I beleive it was .012" ) ? Mine were warped pretty bad, got them right at the spec limit, and pulsation was gone.
                              This does not explain how hard brake applications can fix so many pulsating brakes.
                              Just the other day I noticed my 750 starting to pulsate a little, went out an cooked them by braking hard a few times, now it is smooth as silk again.


                              Life is too short to ride an L.

                              Comment

                              Working...
                              X