Ducati Monster Forum

Moto Board => Tech => Topic started by: Grappa on June 12, 2008, 05:54:04 PM



Title: Grey Clutch Fluid
Post by: Grappa on June 12, 2008, 05:54:04 PM
A few weeks ago I had noticed that my clutch fluid reservoir was looking kind of grey.  I bought a mighty vac, and proceeded to flush out the line and reservoir with a full 12 oz bottle of fluid, till it was looking clean and pristine.  Went on a 120 mile ride last Sunday, and today, few days later, I am noticing that my fluid is starting to look grey again.  WTF?   [bang]    Any ideas as to what may be the problem?

2001 M900 i.e. dry clutch  21,000 miles


Title: Re: Grey Clutch Fluid
Post by: Slide Panda on June 12, 2008, 06:09:25 PM
Ever replace the rubber gasket in your res?  If not... I'd bet that's the source of your grey stuff. 


Title: Re: Grey Clutch Fluid
Post by: Grappa on June 12, 2008, 06:16:12 PM
Ever replace the rubber gasket in your res?  If not... I'd bet that's the source of your grey stuff. 


When I flushed the fluid, I took out the gasket and gave it a good wipe down.  The material did not seem to be old or corroded or falling apart in any way.  Still very...rubbery.


Title: Re: Grey Clutch Fluid
Post by: johnster on June 12, 2008, 06:19:10 PM
Did you just get the bike?

-Reason I ask is because it's completely normal IMO, if what you're seeing is expected darkening (absorbtion of particulates + normal viscocity breakdown)... Most people's clutch fluid turns black (just like oil does) after some time....Check out mine after just 1100 miles from the last time I bled + changed it (last fall)...I wouldn't worry about it... [coffee]

(http://i78.photobucket.com/albums/j88/jpcwon23/P5180259.jpg)


Title: Re: Grey Clutch Fluid
Post by: Grappa on June 12, 2008, 06:27:21 PM
Did you just get the bike?

-Reason I ask is because it's completely normal IMO, if what you're seeing is expected darkening (absorbtion of particulates + normal viscocity breakdown)... Most people's clutch fluid turns black (just like oil does) after some time....Check out mine after just 1100 miles from the last time I bled + changed it (last fall)...I wouldn't worry about it... [coffee]




I purchased the bike used with 18,500 miles.  It now has 21,000.  I figured the fluid would break down a bit, but I just flushed the lines last week and have only gone on one long ride since.  And I mean I REALLY flushed it out.  After the grey went away, I continued flushing, ending up using the whole 12 oz. bottle of fluid.  I used Castrol GTLMA dot 3/4 brake fluid.


Title: Re: Grey Clutch Fluid
Post by: Howie on June 12, 2008, 06:47:10 PM
Clutch fluid turning black is a common occurrence.  Many theories why exist, but that is what they are, theories.  Change your fluid once a year, ignore the color, ride, be happy ;D


Title: Re: Grey Clutch Fluid
Post by: johnster on June 12, 2008, 07:04:06 PM
Clutch fluid turning black is a common occurrence.  Many theories why exist, but that is what they are, theories.  Change your fluid once a year, ignore the color, ride, be happy ;D

+1....   [thumbsup]

Honest to God, when I first got my Duc, I was SO paranoid about every little thing that seemed out of sorts or "different / wrong" as opposed to the Jap bikes + 2-strokes I had ridden in the past, but as cliche' as it sounds, there is some truth in the statement;

It's a Ducati... They do that...     ;D


Title: Re: Grey Clutch Fluid
Post by: Speeddog on June 12, 2008, 07:41:24 PM
It's particulates.

Let your bike sit for a while, and they settle out onto the bottom of the reservoir.

There is no cure that I've heard of.


Title: Re: Grey Clutch Fluid
Post by: Howie on June 13, 2008, 03:41:49 AM
Another "Ducatis do that" syndrome.  My buddy has an old R1 with a hydraulic clutch that turns clutch fluid black.  Aprillias and Guzzis use Brembo hydraulic parts, so I imagine they do it too.  My theory is the black comes from the non anodized aluminum bores in the cylinders.  Some believe it is from heat, some debris from the seals.  Kind of amazing no one has analyzed the particles.


Title: Re: Grey Clutch Fluid
Post by: NvrSummer on June 13, 2008, 06:28:07 AM
Another "Ducatis do that" syndrome.  My buddy has an old R1 with a hydraulic clutch that turns clutch fluid black.  Aprillias and Guzzis use Brembo hydraulic parts, so I imagine they do it too.  My theory is the black comes from the non anodized aluminum bores in the cylinders.  Some believe it is from heat, some debris from the seals.  Kind of amazing no one has analyzed the particles.

I've heard it's from the heat too.  No worries though!  I kinda like it.  Looks better than the whiz quiz cup on the other side!


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