520 EXC clutch Fade

Hi!. After replacing slave clutch cylinder (The one close to countershaft sprocket)after broken chain hit it i have been having problems with the cluch. Right after the system is bled it works fine. After several minutes on the woods it will not work at all. It acts as if it has no fluid on the system. After 20 to 30 pump strokes iit starts to work really close to the handlebar, eventually regains pressure and works fine for a mile or so then it goes away. Maybe it happens when hot and after it cool it comes back?.

I have tryed ATF, Power Steering Fluid, Hidraulic oil used on european cars on Self Leveling Suspensions, SAE 30 to no avail.

I also replaced master cylinder internals from a broken one.

Is the oil sold by KTM really different from all available oils.

Please Help!!!!! :):D

Sure there is enough fluid in? Stupid question I guess, but after putting in my Stainless cable, I took forever to get mine working right.

Not losing fluid at all are you?

The fluid shouldn't make that much of a difference, but I don't see why people shun the Magura mineral fluid?!?!?! Heck, you'll spend more $$ trying other fluids out than just to buy a bottle of "Magura Blood". And KNOWING everything is ABSOLUTELY fine as far as that goes.

Only thing I can think is that mabey there is an air bubble in there, and after time, it rises to the master cyl, and gets pushed down in again in time....only to cause it to not work right. Thats the reason I am wondering about the fluid level.


I'm having the exact same thing happen on my clutch after changing to the EE braided line. I did a search and found this post. Has anyone found out what causes this? It appears the clutch is not bleed correctly put I've done it 2-3 time by the book and my clutch keeps fading away then coming back after several pumps on the lever.

I'll throw my two cents in. I replaced my clutch line with the EE SS one and have a heck of a time bleeding it and getting everything right. Now it works like a champ.

I bled it as the manual says from the slave cylinder up to the master with the Magura blood. Two things I looked for....

First, that I did not push a small bubble of fluid into the line every time I put fluid in from top of the nipple. To fix this I squeezed the lever a bit with the nipple open to force fluid into it and then ensured there was not bubble between the syringe and the nipple. Don't know if this is a problem but it seem to be something that would be easy to happen.

Second, I worried about air at the top of the 90 degree elbow by the master cylinder so I removed the assembly (with the cover on!) and twisted and tapped it to ensure the air had a upward path to reservoir. Again, do not know if this is a problem, but mine works like a champ now.

Hope this helps.

Hey Y'all

Look in the Holeshot message board, Ktm forum, Hydroulic clutch fade at speed. I think it was by Best in the Dez. I just found it on the 2nd page. There are several solutions put forward.

Hope this is what you'r looking for.

See Ya

Okie :):D

I had the same problems you all mention

The simplest solution is to back off the slave mounting screws a half turn and back fill the system with 10-wt hydraulic oil using a syringe. Put the cap on the reservoir and lastly re-tighten the slave fasteners. If you back off the slave too far your clutch will be disengaging. To remedy this crack the bleeder and bleed out just a few drops until the clutch has a little free play

Worked for me

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