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    No front brakes

    So I started putting my bike back together today. Put the front brakes on, and they are useless. There's no effort on the lever, and the caliper doesn't move. There's plenty of fluid in the reservoir (snapped one of the screws trying to check). All I did when I had it apart was take the caliper off the wheel and set it aside. Never disconnected any lines or anything, so there shouldn't be any air in the lines. Where should I start looking?

    #2
    Try pumping the lever several times. You will have moved the pads back when you pulled the caliper and they'll need moving back in to position.
    79 GS1000S
    79 GS1000S (another one)
    80 GSX750
    80 GS550
    80 CB650 cafe racer
    75 PC50 - the one with OHV and pedals...
    75 TS100 - being ridden (suicidally) by my father

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      #3
      I've pumped it repeatedly. Nothing changes. With the caliper off, the pads are barely moving.

      Comment


        #4
        Tear down the system (caliper and master) and maintenance them properly. Most likely air got into the system somehow but consider that a sign. Replace the brake line while performing the maintenance. Brakes are nothing to monkey around with.
        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
          What Ed says. If pumping doesn't bring them back then you have disturbed something. If you haven't serviced the calipers and MC for a while you'll be surprised what gunk you might find in there.
          79 GS1000S
          79 GS1000S (another one)
          80 GSX750
          80 GS550
          80 CB650 cafe racer
          75 PC50 - the one with OHV and pedals...
          75 TS100 - being ridden (suicidally) by my father

          Comment


            #6
            Got the caliper off, the piston will not move. I'm trying nothing but muscle to get it out. Will WD40/PB Blaster/Acetone-ATF ruin anything inside here?
            Last edited by Guest; 02-29-2012, 07:23 PM.

            Comment


              #7
              Not really since you'll want to replace those seals anyway. If you have an air compressor you can try to blow out the piston with that just be careful you have it pointed in a safe direction. Or you can use a couple of screwdrivers to act as levers to pull it up (stick under lip of piston and work it out).
              Cowboy Up or Quit. - Run Free Lou and Rest in Peace

              1981 GS550T - My First
              1981 GS550L - My Eldest Daughter's - Now Sold
              2007 GSF1250SA Bandit - My touring bike

              Sit tall in the saddle Hold your head up high
              Keep your eyes fixed where the trail meets the sky and live like you ain't afraid to die
              and don't be scared, just enjoy your ride - Chris Ledoux, "The Ride"

              Comment


                #8
                Nm, got it.

                Methinks I found the problem

                Comment


                  #9
                  Good man! If you need new rubber seals be sure to get OE Suzuki parts. K&L brake system parts are crap.

                  This thread will help you save money on brake lines...http://www.thegsresources.com/_forum...d.php?t=114521
                  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


                    #10
                    Alright, I'm completely at a loss and about to lose my mind.

                    Got the caliper cleaned out good and back together. Took the master cylinder apart (as much as you can at least, not really a whole lot to take apart) and cleaned it good. I know that the connection between the caliper and the reservoir is good because when I pushed the piston in, it shot air bubbles up in the reservoir.

                    But I'm trying to refill the reservoir and I'm clearly doing something wrong. When I pull the brake handle, it doesn't seem to be pushing fluid down the line. I know the piston is working because I checked it when I removed the master cylinder.

                    The reservoir is full, but everything else is empty. I tried pumping the brakes with the bleeder open and with it closed, no difference. Even tried sucking on the line connected to the bleeder and the amount of fluid in the reservoir didn't change.

                    What am I doing wrong?

                    Comment


                      #11
                      Did you take the MC piston out when you cleaned the MC? Plus did you clean the tiny hole and the even smaller hole that makes the tiny hole look big?
                      79 GS1000S
                      79 GS1000S (another one)
                      80 GSX750
                      80 GS550
                      80 CB650 cafe racer
                      75 PC50 - the one with OHV and pedals...
                      75 TS100 - being ridden (suicidally) by my father

                      Comment


                        #12
                        Go buy a Mitey-vac at autozone or something. Makes life MUCH easier. As to your problem, usually when you disassemble a MC, you need to "prime" it on reassembly to make sure you get all of the air out of, or it won't push any fluid. There are half a dozen different ways people do this, most involve quite a mess . A Mitey-vac will make it both easier and less messy.

                        You didn't say: did you strip the mc and use NEW bits inside? And did you absolutely assure you cleaned out both little ports inside? There are two. One is tiny, and the other is reaaaaally tiny. That's the pressure return port and if it's plugged with gunk, it will cause your brakes to lock up.

                        Comment


                          #13
                          +1 for the Master cylinder needing priming.

                          Comment


                            #14
                            Another person to recommend tearing the MC COMPLETELY apart and cleaning/replacing the piston cup set.
                            Cowboy Up or Quit. - Run Free Lou and Rest in Peace

                            1981 GS550T - My First
                            1981 GS550L - My Eldest Daughter's - Now Sold
                            2007 GSF1250SA Bandit - My touring bike

                            Sit tall in the saddle Hold your head up high
                            Keep your eyes fixed where the trail meets the sky and live like you ain't afraid to die
                            and don't be scared, just enjoy your ride - Chris Ledoux, "The Ride"

                            Comment


                              #15
                              Information on how to prime the master cylinder?

                              I see the Mityvac at Autozone, but for one, they don't have it in stock and two, I'm not paying $80.

                              What about this one for $35?

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