Good effort !Scotty wrote:I agree with what you're saying but if it's a closed system where would the moisture come from?
p.s. This is my attempt at searching the web!!
The system is not fully closed. It cannot be to allow for both fluid movement when you apply brakes and as the pads wear down.
When the fluid overheats it doesn't just overheat the bit at the calipers, it overheats the whole lot that is under compression in the fluid line.
The moisture is absorbed by the fluid through the cap on the
reservoir. This cap has a small breather hole. This is why it is advised fluid be changed every 2 years.
On some bikes the reservoir caps have a rubber membrane that
acts as a diaphram and sits on the top of the fluid to keep it seperate
from the air.
For some reason cars don't seem to do this though (maybe its the amount of fluid level travel required).
