Speaking of brake fluid

 

I was having trouble shifting into neutral because the clutch didn't
seem to release all the way. Then I noticed the reservoir was almost
empty. There are no leaks around the top. Could the slave cylinder be
leaking? I topped it off and things are working better. I also noticed
the fluid was black (dirty) Should it be changed frequently?

 



If it uses brake fluid, it should probably be changed at least every two
years.  A year or so ago, BMW went to a different type of clutch fluid
which, apparently, doesn't require changing.

Tom K.

 



Brake fluid attracts moisture.  Moisture causes rust.  Rust causes brake
cylinder pistons to leak.  I suspect the BMW version does not attract
moisture.

I'm having all fluids changed at this very moment.  My newly-acquired 2003
Wing has had only oil & filter changes.  I'm hoping a difficulty in finding
Neutral will go away.

 



BMW labels it as "Hydraulic Clutch Mineral Oil" so I guess it's not
hygroscopic.


Although my Wing was a 1500, I never had that problem.  The one time I
neglected changing fluids for 3 years, my brakes became so grabby that
smooth stops were extremely difficult.  I guess my brake fluid had become
contaminated but I lucked out with the clutch fluid.  Hopefully your neutral
difficulties will be remedied by the fluid change.

Tom K.

 



If the fluid has black particles I would suspect serious deterioration of
the seals and loss of fluid would tend to confirm that suspicion.

Brake fluid (except DOT5 silicon) is hygroscopic, which means it attracts
moisture right out of the air. In my own opinion it should be replaced every
year, although the fluid in my CBX550 looked as if none of the previous
owners had ever replaced it - the rear brake was totally f****d and the
front brake sort of worked.

The rear brake had to be thoroughly serviced as a matter of urgency, on the
front flushing through several times with new fluid was good enough so I
could replace the seals in my own good time.

Guessing that clutch seals are probably a similar price to brake seals, then
at UK prices a set of seals cost a little less than calling out a recovery
truck.