Clutch Slave

Squeaky back brake? Hard to control at 30mph/40kph?
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wm990
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Clutch Slave

Post by wm990 » Mon Mar 14, 2016 9:14 am

Hi Guys,

Recently purchased my SMT and I think I'm having the common slave failure.

I've removed the slave and can see fluid, I assume you should see no fluid once removed, am I right in thinking that?

I'm going to replace with Oberon slave anyway but still good to know :)

Cheers

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Re: Clutch Slave

Post by kevxtx » Mon Mar 14, 2016 9:40 am

I fitted a Oberon slave to my 2010 990 SMR, moved it to my 2012 SMT, then fitted it to my 1290SD for 23 months & it has not missed a day & works perfectly every pull.

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Re: Clutch Slave

Post by Nickhk » Mon Mar 14, 2016 11:23 am

Any doubts, just change it -I did and I certainly don't regret it !

Good luck!

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Re: Clutch Slave

Post by wm990 » Mon Mar 14, 2016 12:12 pm

Oberon ordered!

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Re: Clutch Slave

Post by wm990 » Tue Mar 15, 2016 9:50 pm

Oberon fitted !! Really easy even if you've not done much to your own bike before.

Feels loads better than before.

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Re: Clutch Slave

Post by OzBeast » Wed Mar 16, 2016 11:56 am

The Oberon is a great slave, I've had no issues with mine on the 1290 and had one in a Ducati as well with no issues. Very well spent money.

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Re: Clutch Slave

Post by wm990 » Thu Mar 17, 2016 7:26 pm

OzBeast wrote:The Oberon is a great slave, I've had no issues with mine on the 1290 and had one in a Ducati as well with no issues. Very well spent money.
Clutch feels absolutely lovely now! I'll be recommending to anyone I meet!

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Clutch Slave

Post by Corailz » Fri Mar 18, 2016 3:10 am

I just changed mine for an Oberon on my SMT and bleeded it twice. After all that, the bike was really hard to move when put in first gear with clutch pulled and engine off. I've tried to do it with the engine on and it was as easy as on neutral when the oil went hot. I've noticed thought that when i'm stopped with the first gear engaged and twisting the throttle with clutch pulled, the bike moves foward like if the clutch is still a bit engaged...The tranny goes from neutral to the first gear smoothly tought!
With a cable clutch i would adjust it, but what to do with a hydraulic clutch? Should i bleed it again or there is another thing that i should do to fix that?

Thanks

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Re: Clutch Slave

Post by OzBeast » Fri Mar 18, 2016 7:31 am

Sounds like there's still a bit of air in the line, do you have a bleed nipple at the master cylinder as well?

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Re: Clutch Slave

Post by wm990 » Fri Mar 18, 2016 7:34 am

I'd had a browse round the forum at other Oberon posts and I'm sure I read it's something to do with how the clutch is lubricated and it's not a problem.

Hopefully someone else can confirm this.

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Re: Clutch Slave

Post by Gary » Fri Mar 18, 2016 2:23 pm

I have a thousand miles on my bike with its original slave. It does exactly the same thing... I thought it was normal...

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Re: Clutch Slave

Post by Buck49x » Sat Mar 19, 2016 12:37 am

When was the last time you rode it before putting the oberon slave on? I thought the same thing but hadnt riden in a long time. After taking it for a quick ride It was way easier to move while in gear with clutch in.

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Re: Clutch Slave

Post by wsmc99 » Mon Mar 21, 2016 4:37 pm

I'm probably the exception here, but I have owned 4 KTM's (1 SDR 1290, 2 950 Adventures and 1 990SMT).
Only my second Adventure had an issue and once I sourced a proper (and upgraded) O-ring I have had no issues.
The upgraded o-ring is a 90 vs 70 durometer.

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Clutch Slave

Post by Corailz » Mon Mar 21, 2016 8:32 pm

wsmc99 wrote:I'm probably the exception here, but I have owned 4 KTM's (1 SDR 1290, 2 950 Adventures and 1 990SMT).
Only my second Adventure had an issue and once I sourced a proper (and upgraded) O-ring I have had no issues.
The upgraded o-ring is a 90 vs 70 durometer.
THAT, could makes sense!
From what i understand, is that the clutch slave cylinder's not pushing the clutch enough to disengage it totally.
I'll try to bleed it again... I've tried to find a bleeder on the master, but it seem to don't have one on my bike. I have the original Magura master thought...

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Re: Clutch Slave

Post by wsmc99 » Mon Mar 21, 2016 8:45 pm

No bleeder on the master, just the slave.

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Re: Clutch Slave

Post by Thirdway » Sun Apr 10, 2016 7:28 pm

It won't be easy to move when cold, with engine off and in gear. The reason is that the bike uses a wet clutch, but, unlike a conventional bike, it uses an advanced form of lubrication termed 'dry sump '. It means that oil is fed to all bearings, plus the clutch by an oil pump rather than being soaked in a bath of oil. The advantages are that the oil is not being thrashed about by the crankshaft which supposedly makes it more efficient. It is also more consistent if the bike is dropped, or going up inclines, cornering forces, down hills. All F1 cars and most exotic road cars use the same system.

Anyway, it means that the clutch is devoid of the lubrication necessary to make the plates free enough to push it around cold, or with the engine off.

As far as fluid leaking from the OEM clutch slave, this doesn't mean it's knackered. When the slave is loosened and removed from the housing, the clutch rod and internal Spring will tend to cock the plastic piston in the bore. The result is a few drops of fluid will leak out because the seal isn't functioning as well when the piston effectively creates an ellipse.

That said, the slave is particularly naff. The Oberon is far nicer and likely to last far longer.

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Re: Clutch Slave

Post by jay-ninja » Wed Aug 02, 2017 8:46 pm

Interesting thread this. I just removed my slave - thinking I had to to remove the sprocket cover (turns out I didn't need to anyway !!). Anyhow, after refitting it the clutch didn't seem to disengage when I pulled the lever in - I bled the system and now it's better - but with the bike on the paddock stand I notice the rear wheel spins - I can stop it with my foot on the tyre but it spins as soon as I take my foot off.

I wonder is this normal or should I try and bleed the system again ? Tempted by the Oberon upgrade though.

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Re: Clutch Slave

Post by wm990 » Wed Aug 02, 2017 10:47 pm

jay-ninja wrote:Interesting thread this. I just removed my slave - thinking I had to to remove the sprocket cover (turns out I didn't need to anyway !!). Anyhow, after refitting it the clutch didn't seem to disengage when I pulled the lever in - I bled the system and now it's better - but with the bike on the paddock stand I notice the rear wheel spins - I can stop it with my foot on the tyre but it spins as soon as I take my foot off.

I wonder is this normal or should I try and bleed the system again ? Tempted by the Oberon upgrade though.
Rear wheel spinning is not an issue at all, there's some explanation about the oil and the clutch plates and some kind of friction but it's normal. Oberon is an awesome upgrade and easy to swap on your own. Highly recommend!

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Re: Clutch Slave

Post by Magic Wand » Thu Aug 03, 2017 8:07 pm

I bought the Oberon cluth slave cylinder and replaced tho original one. It was a bit tricky to get all the air out from the system, but when done it works as expected.
Can´t say that it works better than original Magura, but for sure the Oberon is better quality.
/M

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