contaminated clutch fluid

[Fugly]

Hi guys (& Girls ,o),

After a 3000Km run into and around Germany I've noticed that my clutch fluid appears to be contaminated as it's gone very dark in colour.

Any ideas as to why when all it does is push the slave cylinder to lift the clutch plates?

Oh and the bake brake has all but disapeared so looks like lots of bleeding to be done soon.

Fugly

[markh]

All hydraulic fluid degrades with time. Has it been in long?

The darkening could also just be grime from seals.

[walpole68]

mines black after 2500 miles dealer says normal

[Pomp1]

Oh, the Great Mystery of The Clutch Fluid..
Seriously, everyone suffers from it but nobody has yet got a definitive answer on why that happens..

[Funkatronic]

mine did that too, was fine for first 9k or so then got murkier

had the clutch drained and the slave dismantled, new seals put it and pushrod regreased and within 3-4k its getting murky again

i was worried about my clutch until i saw slobs inky blackness of a resovoir the other week, then i stopped worrying :-)

[mintyhit]

The stuff that came out of my clutch on the rebuild looked like squid ink!

[animaluk]

its caused by heat from the cluch nothing to worry about

[Capo]

its caused by heat from the cluch nothing to worry about

I doubt it, the clutch is on the other side of the engine and the only thing to conduct heat to the slave cylinder is the push rod. However, it will reach the temperature of the engine.

The most plausable reason I have come across is that the discolouration is due to decomposition of the seals. Quite why this should be escapes me as there are billions of hydraulic circuits that do not suffer from this phenomena.

Cheap Ducati seals maybe, but that does not explain why after market cylinders also darken the fluid (unless of course they use ducati seals to make their production easier.

If it bothers you change it (you should do this annually anyway).

[chris yeatman]

my s4r is ths same, could it be a monster thing????

[Capo]

my s4r is ths same, could it be a monster thing????


No, it is common in all Ducatis

[animaluk]

I doubt it, the clutch is on the other side of the engine and the only thing to conduct heat to the slave cylinder is the push rod. However, it will reach the temperature of the engine.

The most plausable reason I have come across is that the discolouration is due to decomposition of the seals. Quite why this should be escapes me as there are billions of hydraulic circuits that do not suffer from this phenomena.

Cheap Ducati seals maybe, but that does not explain why after market cylinders also darken the fluid (unless of course they use ducati seals to make their production easier.

If it bothers you change it (you should do this annually anyway).

I ment heat from the clutch slave (getting as hot as the engine) happens on KTM superdukes as well

[rollo22]

Allegedly it the rubber in the cap that turns it black.
Main dealers reason do we believe them or not?

[Capo]

Allegedly it the rubber in the cap that turns it black.
Main dealers reason do we believe them or not?

The brakes have the same cap and the fluid does not discolour like the clutch.

[banditloon]

Within 30 minutes the nice clean clutch fluid in the beast had gone grey/black/murky. Clutch works fine. Then again the temperature was 29 degrees, I was riding through London traffic and I could BBQ anything on the engine casings and clutch slave cylinder.

Could be worse, I could own an RSV where the rear brake and clutch fluid just goes black just by looking at it, then they fail after 2000 miles! You got to love the RSV!

[Pomp1]

Could be worse, I could own an RSV where the rear brake and clutch fluid just goes black just by looking at it, then they fail after 2000 miles! You got to love the RSV!
Just sold mine..2 sprags and 2 relays in 5 years..but an awesome bike nonetheless Oh, and the clutch does go black in them too, and the set-up is basically the same, so I would exclude being a Ducati seals problem. The engine heat cause is plausible though

[slob]

Does the side of an engine case really get that much hotter than a brake caliper?

[AndyP]

My theory is oxidization inside the clutch slave, although how the oxygen gets in there I'm not sure. Possibly absorbed in the fluid or in the water content of the fluid.
Has anyone tried silicone fluid and noticed any difference?

[Rally]

Fugly,
It did it whilst I had it as well. I drained and renewed it twice (The 2nd time, just before you had it to make it look clean again) but it goes black in no time. My RS is the same. I was tempted to try DOT 5 to see if it helped but was concerned for the seals, so used DOT 4 as recommended. It does seem it is common to everyones bike?

[banditloon]

Just sold mine..2 sprags and 2 relays in 5 years..but an awesome bike nonetheless Oh, and the clutch does go black in them too, and the set-up is basically the same, so I would exclude being a Ducati seals problem. The engine heat cause is plausible though

No stator coils? My mate is now on his second stator coil, and the bike has only just reached 30,000 miles. No idea how many times he has changed the cltuch and rear brake fluid though. Must be about every 2 weeks.

I was told that the dirty fluid just comes from the actual hoses. The rear brake fluid on mine is black, and I hardly use the rear brake. Can't see in the coffin sight glass for the front brake fluid, but no doubt that is black. Actually I best make sure there is some fluid in there tomorrow :mand:

[Fugly]

Hi guys,

Thanks, I'll live with it as won't be doing much more this year as it looks like I've got a business and house move coming up in the next couple of months but intend to get the old girl in (big) bits for a good clean and service over the winter so will change it them along with all the other major bits like belts, brakes etc.

[jerry]

Its the BREMBO Pixies and Elfs