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    need help...front brake

    i was just beginning to bleed the front brake....squeezed the lever, opened the bleed valve..

    some fluid came out of the bleed valve, so i am thinking all is great. closed the bleed valve, and then released the lever...and it was lax. nothing. i can move the lever freely back and forth, it is simply swinging in the wind.

    i took off the banjo fitting, and no fluid is getting through.

    what to do? please steer me in the direction i need to go. the fluid that is in the resevoir was black. i am sure it was not changed in the longest time. is it possible that something lodged in the bottom when the initial bleed pump occurred?

    #2
    Your best bet is to remove the MC, take it apart and clean it. There are a couple of very small passage in the MC that if clogged will not allow fluid to return.
    Black fluid in the reservoir is old and saturated with moisture, you don't want that in your brake system. Rebuild kits are available that will include the piston, spring and seals. Once you put everything back together flush out the lines with some fresh fluid.

    Does your bike have dual calipers? The manual has a bleed procedure for this type of setup.

    Comment


      #3
      It looks to me as if the master cylinder piston has seized or jammed in the bore of the MC. Maybe being pushed in to an area where it has not been before when you were bleeding the brakes. If the fluid in the MC was that black then you need to disassemble the MC anyway and give it a good cleanout.

      Comment


        #4
        i have a clymer manual. yes, dual caliper.

        and now the stupid questions....

        does the brake lever push on the master cylinder?

        and when i take everything off, what should i clean it with? brake cleaner? or any solvent?

        and yes, i suppose it feels like something got jammed in there.

        also, there are some wires attached at the bottom of the brake lever. what are they?

        you guys are the best. what a wonderful resource.
        Last edited by Guest; 08-28-2008, 06:48 PM.

        Comment


          #5
          The brake lever pushes the piston into the MC bore. Your best bet is to clean everything with clean brake fluid. When you get it apart make sure that the MC bore is rust free and does not have deep scratches. I think the manual should have some measurement specs (tolerances) for the bore and piston. Hopefully your piston is not jammed in the bore. The hardest part is getting the snap ring off the MC, you either need long nose snap ring pliers or a scribe to work it out of its bore. Rebuild kits are available from OEM parts suppliers.

          Comment


            #6
            tentatively, i think i fixed it with your help. i pulled out the piston with needle nose pliers, and it sprung back into position. cleaned what i could, reattached the lever, and put the assembly back on the bike. put in brake fluid, and continued the bleeding process with success. there is good pressure at the lever, and the piston is moving freely.

            as i type, taking the mc apart is beyond my abilities. i will ask a friend to come over and take a look at it, but at least i can move the darn thing now.

            this afternoon's project will be trying to get the brake light switch back on. as i was taking it off, a little piece fell out before i could see where it went. i might be screaming for help later on. plus, i saw on ebay a replacement switch kit, and it shows a little spring...i have no spring, or if i did, the spring sprung....only god knows where.

            thanks for the help fellas.
            Last edited by Guest; 08-29-2008, 07:05 AM.

            Comment


              #7
              Originally posted by boathead View Post
              tentatively, i think i fixed it with your help. i pulled out the piston with needle nose pliers, and it sprung back into position. as i type, taking the mc apart is beyond my abilities. i will ask a friend to come over and take a look at it, but at least i can move the darn thing now.

              this afternoon's project will be trying to get the brake light switch back on. as i was taking it off, a little piece fell out before i could see where it went. i might be screaming for help later on. plus, i saw on ebay a replacement switch kit, and it shows a little spring...i have no spring, or if i did, the spring sprung....only god knows where.

              thanks for the help fellas.
              The brake light switch assembly is still avalible from Suzuki....you can get it from bikebandit or flatoutmotorcycles or even your local dealer...
              It doesn't cost much, I just got one myself.
              Bob T. ~~ Play the GSR weekly photo game: Pic of Week Game
              '83 GS1100E ~ '24 Triumph Speed 400 ~ '01 TRIUMPH TT600 ~ '67 HONDA CUB

              Comment


                #8
                i might have to buy one, but i think i have a working one. mine was working just fine until i pulled it apart! i'll know this afternoon.

                bikebandit's schematic identifies as "contact holder" as the little piece that i didn't see where it came from. i have the piece, just don't know what the heck to do with it.
                Last edited by Guest; 08-29-2008, 07:18 AM.

                Comment


                  #9
                  Concerning your master cylinder, be sure you clean out the very small hole in the bottom that equalizes the pressure from the lines to the reservoir when the handle is not being pushed. Very easy to miss, can have serious problems if it's missed.

                  Cleaning anthing that uses brake fluid, like the inside of the master cylinder or the calipers, should only be done with clean brake fluid. Solvents, including brake cleaner, can mess things up.

                  You may not have to buy parts for your brake switch. Your clutch 'safety' switch is the same thing. You can move parts from the clutch side to the brake side, then go into the headlight housing and bypass the wires going to the clutch switch. The good side of that is that you will no longer have to hold the clutch to use the electric starter. The bad side of that is that, if the bike is in gear when you push the starter button, the bike will move, so make sure it's in neutral or you have the clutch pulled.

                  .
                  sigpic
                  mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
                  hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
                  #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
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                  Comment


                    #10
                    You can just use a spring from a ball point pen to make a replacement. Just cut it to length, it worked for me. While your at it shine up the copper "u" and the contacts on the board with the wires then a little dieletric grease before you put it back together.
                    P.s. the contact strip is adjustable it will slide a little on the 2 screws so you can set when the brake light comes on.
                    Last edited by Guest; 08-29-2008, 09:30 AM.

                    Comment


                      #11
                      ok, sure enough, i need a bit of help.

                      i am trying to figure out what to do with the "contact holder" (that is what bikebandit calls it), the little piece that sits on top of the wire contraption, and i guess it is activated by the brake lever.

                      looking underneath the mc unit, where it all attaches, i see the brake lever, and two slots. i assume i have to situate this piece into one of the two slots????

                      if so, which one? towards center, or towards the right?

                      and is it this piece that is moved by the lever, or is it the adjustable contact pad that moves?
                      Last edited by Guest; 08-29-2008, 05:55 PM.

                      Comment


                        #12
                        ok, i think i figured it. but, i am thinking that the wire pad, the thing with the two wires, is worn. i got the brake light to work for maybe 2 minutes, but when i tightened everything, nothing. another hour of playing around, and only inconsistant results.

                        would it be reasonable to simply assume that the worn copper wires are not providing the contact i need?

                        or am i just being dumb?

                        Comment


                          #13
                          The switch is adjustable, try loosening the screws up a little and sliding the switch one way or another and seeing which direction you need to move it to get the light to work properly.

                          Regarding your brakes, sorry to say it but you really need to do a full system tear down and replace the lines. That black crud is all over your brake system and if you don't clean it out, your brakes could lock up at any time and pitch you on the ground. The lines have a scale on the inside which is why then need to be replaced but the master and calipers can be cleaned out and the parts reused if they are in good condition.

                          Good luck.
                          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


                            #14
                            thanks, nessism. you said what was sort of lurking in my mind, only didn't want to confront it. i guess i'll search for the lines, and i guess i'll become a pro at brake disassembly and cleaning.

                            Comment


                              #15
                              I'd have to second what Nessim posts about doing the brake tear down.

                              And, really, I have no great gift for mechanics, but it really isn't difficult if you don't mind taking it slowly and going step by step.

                              This forum is a great resource. I found my reservoir full of black crud too, and the fluid coming out of my lines was just as dark. I'm in the middle of a break system tear down and the parts can all be found on-line.

                              It's not as expensive as you would think, either.

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