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OK, so I've heard mention several times of a "known clutch slave problem" which seems to appear on a number of different models across the board in at least the late '90s and early '00s. In fact, when I had my '01 996 in for it's 6000 mile service, the shop noted that my slave cylinder had never been warrantied or serviced, so they simply replaced it for free under some technical service bulletin even though I had experienced no problems of which I was aware. This weekend I was working on a buddy's 1999 Monster 750 who is having clutch issues for a second or third time. The clutch lines clearly are getting air into them somehow. Even after running an entire bottle of DOT 4 through it, I still can't get it entirely free from air bubbles (and yes, I'm successfully bleeding it without introducing any more air from either end). While actuation is back to functional after my servicing, it bothers me that I can't get it completely bled. Plus, it obviously has an underlying cause that hasn't been addressed simply by bleeding since it comes back after a while. So, my question is, what are the symptoms of a "typical bad clutch slave"? What is this known problem? My buddy is not the kind to spend money on upgrades (although there are obviously many aftermarket clutch slave options specifically because so many had problems), so what are the odds and would it be worth trying to get the dealer to replace his under whatever TSB/Warranty they did mine under? Any other components sound like they might be the culprit? Gracias, amigos.
 

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I think the slave cylinders (old type at least) generally 'leak' to some extent due to the poor quality seals, the fluid in mine used to get black, presumably with chainlube? very quickly, it also required bleeding regularly and once it completely 'failed' - where it lost enough fluid/gained enough air to not work at all, I removed it, stripped it down and rebuilt it and it was OK again but always the black clutch fluid and bleeding issues, you can get a better type of seal which may address these issues.

Last year I fitted an Evoluzione slave cylinder and I have had no black fluid or bleeding issues, it also reduces the weight of the clutch pull whilst increasing the throw of the lever, so allows for easier and smoother clutch operation - something that is a great benefit if I get caught in stop-start traffic. Also I recently fitted 'Speedbleeders' so although the new cylinder doesn't need bleeding like before it makes the job easier - I just changed all the clutch and brake fluids and it took me a fraction of the time that it used to as I can just leave the nipple open and pump.
 

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I also have the "old" slave cylinder for my clutch.

The seal fitted from factory suck and let both air in and fliud out, so the clutch deteriorates during the summer leaving me a winterjob every winter to flush the system and replace the seals. I´m now going for a replacement to a triple-seal type slave.

This seems to be tha case for most older Ducati´s. There is a joke about the fact that a true Ducatista should be able to exchange seals and bleed the system during a short cofeebreak.. While his/her mates are having cofee that is.

Some newer bikes have an upgraded slave.. but I´m not sure if they became starndard on 2001 or after that. I know my brothers 2001 996S was recalled for some form of clutch trouble.

//amullo
 

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85 HD, 87 Paso 750, 94 Bimota DB2, 94 GSXR750, 96 GSXR1100, 98 ST2, 00 R1, 01 M900, 02 748, 03 999
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My 1998 ST2 had the dreaded clutch slave start leaking at about 12,000 miles. The seal went bad and the fluid leaked down the side of the case where the countershaft sprocket is. It also leaked in through the clutch rod, into the case, and resulted in the end of the shaft being pitted and worn. I then replaced the original slave with a 2002 clutch slave and replaced the clutch rod with the newer, shorter one. That slave lasted about 5000 miles. It now has an Evoluzione slave and worked well, other than neutral is difficult to find, sometimes. My 2002 748 will get the upgrade once it starts leaking, too.
 
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