Cosmokenney
Husqvarna
Pro Class
So I finally decided to buy the $147.00 OEM clutch hose to replace my damaged one. No aftermarket dealers listed the '17+ as an option, so didn't feel like risking getting a brembo hose for my stock magura clutch.
Regarding the bleed, there are few things you should know. The slave has a bleed nipple, but its tiny. It takes a 6mm wrench. I didn't have one so I machined one from some scrap steel I had lying around.
Then I had to use a tiny diameter hose I had from an old mountain bike brake bleed kit. And I could not reverse bleed it with a syringe. There was no way I was getting fluid in there with a plastic syringe. I'm guessing either the system is closed when the lever is out or the nipple opening is just too small.
Next thing (the alert), don't follow the advice on youtube about bleeding KTM clutches. I saw two or three video that talked about pulling the slave after bleeding and pressing the piston in and letting it return many times to push air up into the master (with the cover off).
The slave on this bike must be a magura specific thing since there is no snap ring to hold the piston in place. So as the system builds pressure the entire slave will come apart in your hands. What holds the piston in place is the fit into the case. In other words there is a rubber boot clamped into the piston and that wraps around the edges of the piston and has a bead that fits into a groove on the outside of the cylinder. When the slave is in the case that bead cannot come out because of the low tolerance between the case opening and the slave cylinder. But the bead pops right off if the slave is out of the case. And that will drain brake fluid that you just bled into the system! I got the slave back together just fine, put it back in the case and re-bled. It was at this point I noticed something on the floor behind where I was working. The return spring fell out of the piston and I didn't notice it. So I had to pull the slave again pull it apart and reassemble. Re-install it and re-bleed it. And... see below for what happened next.
Second note, if you do take the slave out (say, for a rebuild) make sure you get the slave inserted straight. First you can only insert it so far because of the return spring pushing the piston out. So you have to line it up. Insert it part way as straight as you can, hold it there, then get a few threads started on each of the three bolts. Then go around a couple turns at a time in round-robin fashion to slowly draw the slave in -- and straight. Otherwise, it will jam the piston. That's what happened this time. So see below for what happened next.
If your slave piston jams, take the slave out, open the bleed nipple and shoot some compressed air in there to pop it out without having to disassemble the entire thing. Make dam sure you only give it a little blip of air and hold the piston as tight as you can so it won't come flying out.
Now see the second note above on how to properly reinstall the slave. Then see below for what happened next.
At some point, I think when my slave jammed, it caused the master to jam too! So, by now I've had my slave off several times. And had to take it off again. And gingerly pump the (now un-jammed) piston several times with the cover on, to un-jam the master.
In the end, I bled the system normally with the old fashioned pump the lever and open the bleeder. Works well enough to get the air out as far as I'm concerned.
We'll see how long my master and slaves hold up. I'm sure I've probably damaged both cylinders in the master and slave. So I may be buying some new ends to match my new hose. :-(
Cosmo out.
...now, where'd I put that monkey wrench. ;-)
Regarding the bleed, there are few things you should know. The slave has a bleed nipple, but its tiny. It takes a 6mm wrench. I didn't have one so I machined one from some scrap steel I had lying around.
Then I had to use a tiny diameter hose I had from an old mountain bike brake bleed kit. And I could not reverse bleed it with a syringe. There was no way I was getting fluid in there with a plastic syringe. I'm guessing either the system is closed when the lever is out or the nipple opening is just too small.
Next thing (the alert), don't follow the advice on youtube about bleeding KTM clutches. I saw two or three video that talked about pulling the slave after bleeding and pressing the piston in and letting it return many times to push air up into the master (with the cover off).
The slave on this bike must be a magura specific thing since there is no snap ring to hold the piston in place. So as the system builds pressure the entire slave will come apart in your hands. What holds the piston in place is the fit into the case. In other words there is a rubber boot clamped into the piston and that wraps around the edges of the piston and has a bead that fits into a groove on the outside of the cylinder. When the slave is in the case that bead cannot come out because of the low tolerance between the case opening and the slave cylinder. But the bead pops right off if the slave is out of the case. And that will drain brake fluid that you just bled into the system! I got the slave back together just fine, put it back in the case and re-bled. It was at this point I noticed something on the floor behind where I was working. The return spring fell out of the piston and I didn't notice it. So I had to pull the slave again pull it apart and reassemble. Re-install it and re-bleed it. And... see below for what happened next.
Second note, if you do take the slave out (say, for a rebuild) make sure you get the slave inserted straight. First you can only insert it so far because of the return spring pushing the piston out. So you have to line it up. Insert it part way as straight as you can, hold it there, then get a few threads started on each of the three bolts. Then go around a couple turns at a time in round-robin fashion to slowly draw the slave in -- and straight. Otherwise, it will jam the piston. That's what happened this time. So see below for what happened next.
If your slave piston jams, take the slave out, open the bleed nipple and shoot some compressed air in there to pop it out without having to disassemble the entire thing. Make dam sure you only give it a little blip of air and hold the piston as tight as you can so it won't come flying out.
Now see the second note above on how to properly reinstall the slave. Then see below for what happened next.
At some point, I think when my slave jammed, it caused the master to jam too! So, by now I've had my slave off several times. And had to take it off again. And gingerly pump the (now un-jammed) piston several times with the cover on, to un-jam the master.
In the end, I bled the system normally with the old fashioned pump the lever and open the bleeder. Works well enough to get the air out as far as I'm concerned.
We'll see how long my master and slaves hold up. I'm sure I've probably damaged both cylinders in the master and slave. So I may be buying some new ends to match my new hose. :-(
Cosmo out.
...now, where'd I put that monkey wrench. ;-)
