My neighbor owns a '99 CBR1100xx and he told me yesterday that he was going to replace his brake/clutch oil 'cos they haven't been replaced since he bought the bike.
Now I thot those fluids only need topping off if required and dont actually need to be drained and replaced. Is my understanding correct?

Or is he right in saying that after a few years, they need to be actually replaced?

 

Those fluids should be replaced at regular intervals. Even though its a sealed system you still get moisture in them so they need to be replaced. Generally every 2-3 years.

 

hmm...makes sense...

 

well thats actually what i was thinkin but then i took a look at my clutch fluid this mornin before ridin to work an noticed it was almost black! is this normal wear on the fluid or is something else wrong?

 

You can change it more often but the clutch fluid is gonna be dark. Where the slave cylinder pushes on the clutch rod is a nasty area and even though there is a seal some of the ick gets through. How and why it migrates upwards to the reservoir is a mystery to me.

 

I read on one of these forums that the clutch fluid turns dark because the clutch line goes so close to the engine and gets hot. My 06 only has 500 miles on it and the fluid was black by the end of the first week.

 

Clutch fluid does get warm but nothing like the brake fluid -- I mean you can literally boil brake fluid when you're into it hot and heavy. And on the 1kRR it's all DOT4.