Brake Fluid

[Charlie Guthrie]

As the punch line to a "famous" religious joke regarding public confessions,
"Don't believe I'd have told that one, Mike"

"We have not bled the
brakes of our NASA SE-R cup cars except for when we
replace components like calipers all season so far if
you can believe that."

There are good reasons for changing brake fluid which all revolve around the
hygroscopic (moisture absorbing) properties of brake fluids. Some absorb
more moisture than others, so the recommended change interval can vary. The
two bad things that happen most often are 1. brake boiling, and 2. brake
component corrosion (rust).
If you use your on track, most drivers schools recommend fresh fluid within
one month of the track event. Boiling fluid on track....BAD. The B13 cars
with original brakes are bad for heating the brakes and boiling fluid. We
boiled Ford Heavy Duty and got spongy pedal with ATE Blue before going to
the NX brakes. After the NX brakes, ATE works just fine, Motul probably
would be just as good. If you are reasonably easy on brakes (no track time,
no long down hill braking in the mountains, etc.) then off the shelf brake
fluid should be just fine. I am not an expert (not even close), but if I
were not changing fluid about once a month I would consider the synthetic
fluid just because it is supposed to resist moisture better.
The second enemy, rust, is easy to avoid with annual changes of fluid. In
the grand scheme of things, brake fluid is more important than motor oil in
preserving your car and your butt.
Charlie Guthrie
more opinions than time to write them :-)