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    fork air pressure tubing?

    My 1980 GS850 has a plastic airline that connects to both Schrader valves atop the fork tubes. Do they sell replacement kits for this? it just started leaking. All the connections are compressions style brass, and I think are fine, the tube is pretty beat up and would like to just replace that. Not sure of the material.

    Thanks,
    Mark
    -Mark
    Boston, MA
    Suck Squeeze Bang Blow..
    sigpic
    1980 GS850G with 79 carbs.....

    #2
    How are the springs? If you go with Sonic fork springs you won't need air anymore and can cap that valve off.
    Roger

    Current rides
    1983 GS 850G
    2003 FJR 1300A
    Gone but not forgotten 1985 Rebel 250, 1991 XT225, 2004 KLR650, 1981 GS850G, 1982 GS1100GL, 2002 DL1000, 2005 KLR650, 2003 KLX400

    Comment


      #3
      The "balance tube" is some sort of aftermarket or homemade kit; it's not something your bike came with from the factory.

      The 1983 model had a similar arrangement, but it involved sealed collars just above the lower triple. I guess there was some inexplicable craze in the '80s for using air pressure in forks. Maybe Suzuki needed to use up a train load of incredibly weak springs. Just a terrible, doomed idea all around; the air pressure wears out seals sooner, and is highly prone to failure. The best way to go is as Burque noted; straight-rate Sonic springs in the correct rate with no added air pressure.

      Anyway, your best route by far is to just get rid of the air tube system. Since it isn't stock, we have no idea exactly how to accomplish this without pictures.

      Your stock forks have those weird angled aluminum caps, with brass fittings screwed into them and standard Schrader air valves (as used on a tire). There was also originally a chromed cap that screwed onto the air valve bit.

      Depending on how the balance tube kit worked, it could be as simple as replacing the valve cores. If it replaced the brass fitting screwed into the fork cap, then you might need to scare up some on fleaBay, or post a "parts wanted" ad here.

      Here's an example from fleaBay:


      Last edited by bwringer; 04-05-2021, 09:18 AM.
      1983 GS850G, Cosmos Blue.
      2005 KLR685, Aztec Pink - Turd II.3, the ReReReTurdening
      2015 Yamaha FJ-09, Magma Red Power Corrupts...
      Eat more venison.

      Please provide details. The GSR Hive Mind is nearly omniscient, but not yet clairvoyant.

      Celeriter equita, converteque saepe.

      SUPPORT THIS SITE! DONATE TODAY!

      Get "The Riding Obsession" sport-touring motorcycling podcast at https://tro.bike/podcast/ or wherever you listen to podcasts!

      Comment


        #4
        I agree with ditching the air, but if you must... McMaster-Carr sells all kinds of tubing. I suspect some FEP tubing would be good. Use calipers to measure the OD and then order accordingly.

        McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
        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
          Thank you all for the responses. I may need to bite the bullet and get springs.
          -Mark
          Boston, MA
          Suck Squeeze Bang Blow..
          sigpic
          1980 GS850G with 79 carbs.....

          Comment


            #6
            Thank you, yes I was fine with finding the size, just wasnt sure the material to hold up to the fork oil.
            -Mark
            Boston, MA
            Suck Squeeze Bang Blow..
            sigpic
            1980 GS850G with 79 carbs.....

            Comment


              #7
              Whatever you do, DON'T use a regular air pump on your forks, even though it may be a standard air valve. That would blow out the fork seals. I'll post a picture of the proper air pump.
              1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

              2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

              Comment


                #8
                Originally posted by mvalenti View Post
                My 1980 GS850 has a plastic airline that connects to both Schrader valves atop the fork tubes. Do they sell replacement kits for this? it just started leaking. All the connections are compressions style brass, and I think are fine, the tube is pretty beat up and would like to just replace that. Not sure of the material.

                Thanks,
                Mark
                That sounds like a Honda setup I had on a GL500....you might look toward them.... I don't like the air setups on Suzuki much- kind of tricky getting both sides the same(which the Honda setup cures)..a bicycle pump and A SPECIAL LOW PRESSURE AIR GAUGE are wanted carried in the tool kit if you haven't had the bike long enough to know that.

                .....If you were to simply ignore it, or even put some spacers in to pretension the springs or even fiddling with fork oil weight (meh), before you go for the stiffer springs....

                I will mention too that lifting the front wheel off the road, cracking the valves, will equalise the pressure. You might even hear a little "phhht" ! The same thought applies to all bike because they all have airspace and are supposed to be sealed airtight...but pressurised forks require even better seals...

                Comment


                  #9
                  image.jpg

                  The proper pump for a fork air system, such as came on my 11EZ. I don't run any air in it, though, as I installed new straight rate springs.
                  1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

                  2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

                  Comment


                    #10
                    Nice! but a small portable bicycle pump works too. Though indeed, removing a bicycle pump always gives a little "whisht", which is about 2# of the pressure so carefully applied and is awkward.
                    Last edited by Gorminrider; 04-05-2021, 11:41 AM.

                    Comment


                      #11
                      Whatever you do, it's important to get this sealed up; even without added pressure, the air trapped inside the forks acts as a secondary spring as the forks compress. And if the balance tube is broken, it's probably making a mess.
                      1983 GS850G, Cosmos Blue.
                      2005 KLR685, Aztec Pink - Turd II.3, the ReReReTurdening
                      2015 Yamaha FJ-09, Magma Red Power Corrupts...
                      Eat more venison.

                      Please provide details. The GSR Hive Mind is nearly omniscient, but not yet clairvoyant.

                      Celeriter equita, converteque saepe.

                      SUPPORT THIS SITE! DONATE TODAY!

                      Get "The Riding Obsession" sport-touring motorcycling podcast at https://tro.bike/podcast/ or wherever you listen to podcasts!

                      Comment

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