"polygonum" wrote in message
...
On 18/05/2016 22:33, Tim Watts wrote:
It matters not - if some fraction of the mix boils, the brakes fade. It
doesn't matter if the hydraulic fluid is OK, whilst the water is boiling
off.

It matters in that they are two different mechanisms.

Nope, it is always the WATER boiling.

Either might be quite able to let you crash your car because it won't
stop.

It is always the WATER boiling.