Originally Posted by aus
What's the wet boiling point of the AP fluid?
I remember LMB saying it's the wet boiling point that determines how often you need to change your fluid.
199°C / 390°F. http://www.apracing.com/info/info.as...uid+Details_48
That is using the SAE J1704 test method (4% moisture). In reality, 4% is a heck of a lot of saturation, well beyond a 2-year change in a closed system.
The rule of thumb is a full flush every 2 years for a street vehicle. For track days, a quick flush after every event. I like to do a quick bleed the night before an event just to make sure what is in the caliper is fresh and any trapped air is out.