That is the correct fluid.

Not uncommon for the clutch fluid to darken. Compared to brakes, the clutch system goes full travel every time it the lever is used. So there is more wear, but also more area to pick up dirt.

If it darkens quickly, might be a good time to flush it again. If it is picking up contaminants that quickly, there is probably residual crap in there from years of use.

 

My clutch fluid always darkens faster than the brake fluids but 3 months is way too fast. It should last at least 12 months. I'd try giving it a good flush again.

 

Thanks for he reply's, will redo the clutch fluid again.

Regards
Shamless

 

Try removing all the stuff in the reservoir with a syringe or something then wipe out the reservoir really good so it's clean enough to drink out of. Then flush the line completely until clear fluid comes out. :niceone:

 

First of all, you can safely use dot 5.1. I am using motul 5.1 without any issues. Br sure to use 5.1 and NOT 5. As for the color I wouldnt worry so much. What I did was to install a SS line for the clutch and also installed the optional rubber shield in the master cylinder which greatly helps in keeping all the dirt coming from the front sprocket away from the cylinder and the clutch fluid. Now, the fluid is always clean. I just replace it every ~ 1.5 years. I believe this rubber shield comes as standard for the k5 and onwards models. Check yours. For SS line, I recommend goodridge but other brands like galfer are good enough.

 

i had a ducati 996 that done this,i tried everything to get the brake fluid to stay clean in the reservoir,could of ate your dinner out of the reservoir after a drain and clean,then took the clutch hose off,loads of cheap clean brake fluid through it until it ran clear,but after a few rides it just went dark,a lot less than 3 month,i used fully synthetic 5.1 brembo fluid
i gave up trying and just accepted that it went black,but the rear brake and the front brakes kept their colour for ages in their reservoirs........in the end i put brembo reservoir socks over both so i could not see it anymore as i don't like been beat :bash: hth

 

Castrol GT-LMA brake fluid is the trick it made for high temp use.
Someone on this forum when I first joined tested several different fluids because of the darkening.
I have been running it in my bike ( 2003 SV1000N ) since 2006 I only change it every few years stays clear.



Castrol Brake Fluid exceeds all factory DOT specifications. Compatible with all British brake systems.
Exceeds DOT 3 and DOT 4 requirements
Unique Low Moisture Activity (LMA) formulation provides maximum protection against vapor lock brake failure
Maintains a higher boiling point than conventional brake fluids
Superior protection against chloride and zinc corrosion of braking system parts
Exceeds specifications SAE 1703, SAE 1704, ISO degrees 25, JIS K2233 and FMVSS No. 116 DOT 3 and DOT 4

 

Reviving an old topic.
Those 8 posts are great, but there is no conclusion.
I'm facing the same ''problem'' (if it is a problem at all) from - I believe since I flushed clutch fluid for the first time. That is for the last 1,5 years.
Fluid becomes dark after 2-3 rides. No matter which fluid I use (DOT4, DOT5.1, 3 different ''manufacturers'',...).
Cleaned the reservoir completelly, it was like new. Flushed the clutch system until the fluid coming from slave cylinder was perfect and continued for another 2-3 reservoirs - fluid gets dark after 2-3 rides.
Clutch works perfectly, no fluid leaks.
I can ''ignore'' dark fluid, but should I be worried about master and slave clutch cylinders?
I home brewed / DIY-ed some kind of rubber hose / tube protection on the clutch pushrod after relpacing pushrod and seal to avoid pushrod to become corroded again. And if the theory is that dirt from chain / sprocket contaminates the fluid in clutch slave, my brew should prevent that at least a little bit.
Since I'll tinker my bike during the winter (SBK bar conversion, which includes clutch line replacement), should I consider clutch master and slave internals replacement?
It seems that slave internals were never available, only complete slave 23160-06G01-000 (2003, which is not available anymore) or only rubber protection 23163-06B00-000 or 2005+ complete master 23160-06G03-000 (which also isn't available anymore) or rubber protection 23163-06B00-000.
I won't buy original master for 291 € either.
Are experiences / conlusion something like ''Clutch fluid gets dark really fast, but this is nothing to be worried about, flush / replace each year.'' ?
Thank you very much in advance for any kind of opinion / experience / tip.

 

I found the reason for the darkening of the fluid in the clutch reservoir. This is caused by the coating inside the clutch cylinder. The coating is scraped off by the steel piston of the drive and it is forced into the reservoir. I removed the remaining coating with very fine sandpaper and polished the surface. Then I ordered a new brass piston from a turner and for six months now the fluid has been as if it was poured yesterday.

 

Oh, thank you. You mean master cylinder, right? Which piston have you ordered? Link would be much appreciated.

 

I polished the main cylinder, the one that is bolted to the engine. The coating there, in my opinion, serves to strengthen the cylinder walls, but it does not cope and ends up in the reservoir on the clutch handle over time. I completely removed this coating by polishing the cylinder, and replaced the steel cylinder with a brass one to prevent repeated wear of the cylinder walls. A turner from a neighboring garage made it for me based on a sample. Now I do not encounter clouding of the liquid in the reservoir.

 

A OK, now I understand, thank you. So it is a slave cylinder problem. And if I understand you correctly your local machine shop machined new brass cylinder insert / sleeve and piston for you.
If I'd hire local machine shop for that, taht'd be at least 100€, probably more. On the other hand, there is complete brand new OEM bolt-on Clutch slave cylinder available in Hungary (neighbour EU country) for 95€. I'll most likely order it from there.

 

I did not make a bushing, only a piston in the size of the cylinder. In addition, you can make a piston from aluminum, as Honda does. The price of 100 euros is amazing. It cost me 10 euros. In addition, a new cylinder will deteriorate just as quickly and there will be the same problems.

 

A OK so it was only a piston that guy made for you, that is something else. You wrote

replaced the steel cylinder with a brass one to prevent repeated wear of the cylinder walls

so I thought that it was both, piston and cylinder.
I'll remove the piston and ask machine shop how much they'd charge me for that piston.