Brake Fluid Application Guide and
Tips :
Due to the extreme operating
temperatures of a high performance brake system, standard
'off-the-shelf' brake fluids are not recommended. Of critical
importance in determining a fluids ability to handle high
temperature applications is the Dry Boiling Point and
compressibility.
The Dry Boiling Point is the temperature
at which a brake fluid will boil in its virgin non-contaminated
state. The highest temperature Dry Boiling Point available in a DOT
3 fluid is 572 F
The Wet Boiling Point is the temperature
a brake fluid will boil after it has been fully saturated with
moisture. The DOT 3 requirement for wet boiling point is a minimum
temperature of 284 F.
There are many ways for moisture to enter
your brake system. Condensation from regular use, washing the
vehicle and humidity are the most common, with little hope of
prevention. Glycol based DOT 3 & 4 & 5.1 fluids are
hygroscopic; they absorb brake system moisture, and over time the
boiling point is gradually reduced.
We do not recommend using DOT 5 fluid in
any racing applications. DOT 5 fluid is not hygroscopic,
so as moisture enters the system, it is not absorbed by the fluid,
and results in beads of moisture moving through the brake line,
collecting in the calipers . It is not uncommon to have
caliper temperatures exceed 200 F, and at 212 F, this collected
moisture will boil causing vapor lock and system failure.
Additionally, DOT 5 fluid is highly compressible due to aeration and
foaming under normal braking conditions, providing a spongy brake
feel. DOT 5 fluid is best suited for show car applications where its
anti-corrosion and paint friendly characteristics are
important.
Whenever you add fresh fluid to
your existing system (never mix fluids of different DOT
classifications), it immediately becomes contaminated,
lowering the boiling point of the new fluid. For maximum
performance, start with the highest Dry Boiling Point available,
flush the system completely, and flush it regularly, especially
after severe temperatures have been experienced.
Brake
system capacities vary on differing vehicles. Typically 2
Pints (or approximately 1 Liter) should be sufficient to completely
flush the old fluid and replace with new. We recommend 4 Pints
or 2 Liters of Fluid to be certain that your system is completely
flushed of old fluid- and this also allows for some extra
fluid to
spare.
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