Hydraulic clutch issues

[Pittenger5]

So I went for the first ride in months today. Coming off the bridge from South Beach (I think YEEEAAAAAHHHH from CSI Miami every time I ride on it. I hope I see Horatio someday) anyway, my clutch decided to shit the bed. Was fairly sudden, I just had a fraction of the clutch effect. Anyway, manage to stumble up the road a bit with it going from literally 0 clutch effect, to MAYBE 50%. Kept bouncing back and forth. Made it to a Home Depot, check the reservoir, and it looks a bit low, the intake is essentially covered by a smidge of fluid. Run to the supermarket, get some oil fill it up, pump it a bit and its back to full use.
Questions
1. Does the fluid just eventually burn off? Or is there a leak somewhere? (I looked, didnt see anything major).
2. Since I ran it for a while with air in the clutch and stuff, do you think its worth breaking it all down and checking out the springs and packs and stuff?
3. Anything else i should check to make sure everything is privy?

[FireboltEric_MA]

Hydro fluid don't evaporate. Ya got yourself a small leak somewhere.

[OreoGaborio]

Normally, a whole hydraulic clutch system is essentially just the master cylinder, the hydraulic line and the slave cylinder which actuates the clutch.

Flush the system with fresh dot 4 or whatever it wants* and check all three for leaks. If you go through this & everything seems fine but you continue to have problems, you may need to rebuild or replace the master or slave (more than likely it will be the slave as that's generally the weak point of the system).



*If it says dot 5.1, just use dot 4 or even dot 3. They're all compatable.
If it says dot 5 (it won't) use dot 5.
If it says mineral oil, use mineral oil.

[butcher bergs]

I agree with Eric.

I also suggest you wipe down with plain ol' water any surfaces that contacted the fluid. Brake fluid (which also clutch fluid) attracts water (hygroscopic) but can fairly easily be cleaned up. The fluid will damage painted as well as most plastic surfaces.

[Pittenger5]

It requires mineral oil, which I used to top it off to make it home

[OreoGaborio]

added to my post above.

[Pittenger5]

Mind you the bike has 4500 miles on it, and this is the first time Ive touched the clutch in any fashion

[butcher bergs]

Like straight up mineral oil? This your KTM?

[Pittenger5]

Yessir

[Kurlon]

The Magura clutch slaves KTM uses are notorious for leaking. Odds are you're due for a slave rebuild or a new slave. The rebuild is cake, just a couple o-rings, so I'd aim for that first.

If you have to replace it, consider moving to a Brembo DOT 3/4/5.1 brake fluid based setup from a different year Kabooom. They seem a bit sturdier. You'll need the whole setup, master and lever, line and slave.

[butcher bergs]

Whoops! My bad on the brake fluid comments. Obviously mineral oil doesn't attract moisture.

Check for leaks.

[Kurlon]

Whoops! My bad on the brake fluid comments.

It does smell baby fresh if you use Johnson and Johnson baby oil though!

Edit: I think I have a bottle of the lubriciously priced 'Magura Blood' at home still...

[Rambunctous]

I found that it sometimes helps to remove the clutch lever and then using a rod of some sort to push and prime and bleed the system. Then reinstall the lever. I think it is because the levers are adjustable for height.

[TheIglu]

Rebuild the slave and call it a day. Rebuild it again in 4499 miles.

[Kurlon]

I bleed the system from the slave. Pop it off, and pop the cover off the master. Push the slave piston all the way in which will cause bubbles and mineral oil to spew out of the master. Fill the master, pump SLOWLY to push the piston forward, being careful not to let it go too far. Press the slave piston in slowly and observe for air. Repeat till you get a clean dumping of the master's contents on your shoes, fill one last time and reinstall slave and cover.

[Pittenger5]

Is there a howto somewhere on how to rebuild the slave?
How do you drain the existing fluid in there?
And is any type of mineral oil (like from the supermarket) ok, or do I need some super duper motorcycle specific nonsense?

[Kurlon]

Draining the existing fluid: Unbolt clutch slave from the bike, and hold over a tupperware container, pump the master slowly to push the piston out. Keep pumping till it stops making embarrassing sounds and you stop giggling.

Rebuild instructions: Hit up the KTM Talk forum for tips? Pretty much it's replace orings on piston, lube up with mineral oil, push back in.

As far as the oil, Johnson and Johnson baby oil works fine and smells great.

[Pittenger5]

So I took the bike out for the first ride since we moved, and the clutch was FINE when I left, a little soft, but nohting concerning. By the time I made it home ~45 miles, with 40 of it on the highway, I had about nothing left. Still dont see any leaking. Figure Ill rebuild the master, so where do I buy the master rebuild kit?

[Chippertheripper]

A new slave is about $150 if you really fuck it up, FYI.

[Pittenger5]

What other choice do I have?

[Kurlon]

It's not your master, it's your slave, I'll put money on it.

Any place that sells KTM parts should have slave rebuild kits.

http://www.championcycles.com/fiche_...008&fveh=50933

The gasket costs a bit over a dollar, the oring is a dollar...

Reading Material: http://www.advrider.com/forums/showthread.php?t=567964

I can't find an aftermarket replacement at the moment, Oberon has mentioned they have one in development but no signs of it anywhere yet.

[Pittenger5]

Yah, slave, thats what I meant. Whatevs panda bear. There is a KTM place in Austin, but its a bit of a drive, figured Id try to order them online, but Ronayers blows ass. And I cant remember where else does OEM parts.

[Chippertheripper]

Cliffs will mail.
Or ktmcyclehutt if you must order from a big parts supplier.

[number9]

Me trying to rebuild my Magura clutch master on the KTM is like watching a monkey trying to fuck a football. What am I doing wrong?

I ordered an OEM rebuild kit and it seems like the snap-ring is too small for the plastic washer. But, the new parts are the same size as the old parts, so I'm sure it's actually user error. When I install the snap-ring, it doesn't cover the whole washer:



What am I doing wrong? It's almost as if I'm not getting the washer and snap-ring down deep enough into the master, and that I'm trying to install everything in the wrong groove.

[tls25rs]

looking at that picture the materials below the snap ring are not allowing you to get the groove the snap ring goes into clear so that the ring can snap in.

I'm guessing you have already pulled them out and tried again but typically there shouldn't be too much resistance to the plunger etc. going into the body of the master if there isn't a line attached with fluid in it. If the master is still on the bike connected to the line and there is fluid that could make it more difficult to compress as you are in effect pushing to disengage the clutch stack.