View Single Post
      01-20-2010, 05:04 AM   #153
AP Racing - Chris_B
Brake Maven
AP Racing - Chris_B's Avatar

Drives: E34 540i/6, others
Join Date: Jan 2009
Location: SoCal

iTrader: (0)

Originally Posted by aus View Post
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.
199C / 390F.

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.