05-13-2022, 09:32 PM
(05-13-2022, 05:38 PM)Tev62_imp Wrote: I wonder if the clutch system comes complete with master/slave cylinder and the line prefilled with Dot 4 before it gets to the production line? I mean from a different supplier to the brake system. My 2017MY had very different clutch and brake fluid colours when I bled mine last year. I would be 99% sure the previous owner didn't have either bled as it had the original engine oil in the bike at 9,000km (He had the first service and that was it). I can't imagine one discolouring more than the other in the same timeframe and it could just be down to two different fluid brands.
I also assumed dark was "bad" and certainly I still can't help to think otherwise. Oxidation destroys.
That said, the fluid needs to be exposed to air and other contaminants. The last vehicle I had a brake fluid bleed performed was back in 1993. Most of my cages go the whole lifetime without a brake fluid bleed as long as the system remains closed. If it is not, then fluid change ought to be done. The last m/c bleed I did was in '84 because the reservoir "wasn't a closed system" (it was cracked).
I have had these discussions with service garages many times over the years and they don't do it unless a major brake service is being done. I can't imagine the environment liking having to process used brake fluid at a frequency of engine oil changes.
Today's hydraulic fluids and closed systems isn't our father's nor grandfather's. Nevertheless, I keep evaluating and asking technicians from time-to-time to look for a variation in opinion. Maybe motorcycle systems need to be bleed more often due to its smaller closed system footprint. However, I have not heard that argument either.