Series 500 High-Performance DOT 3 Brake Fluid
As the brake system heats up, brake
fluids with low boiling points begin to vaporize.
The brake pedal must travel further to apply the same
amount of force on the brakes, causing a spongy feeling.
If enough of the brake fluid vaporizes, brake system
failure may occur. Brake fluid boiling points are
measured on two separate scales:
- Dry equilibrium reflux boiling point (ERBP) -
the boiling point of new, freshly-opened, unused
- Wet ERBP - the boiling point of a brake fluid
after it has absorbed three percent water.
The minimum dry ERBP for DOT 3 brake
fluid is no less than 205°C (401°F), and the
minimum wet ERBP is 140°C (284°F). That might
not seem very high, but in most brake systems the
fluid in the caliper wont reach that temperature
unless the brakes are abused. It only takes four percent
water contamination to bring a DOT 3 fluids
boiling point down to the federal limit.
AMSOIL Series 500 High-Performance
DOT 3 Brake Fluid is formulated with the best zinc-based
anti-corrosion additives and pH stabilizers. It is
designed for high-temperature stability, yet flows
easily at low temperatures. AMSOIL Series 500 High-Performance
DOT 3 Brake Fluid's superirior additive package provides
good lubrication throughout the system and can raise
boiling points to more than 232°C (450°F).
It keeps water in suspension, slowing its effects
on the brake system. AMSOIL Brake Fluids have high
boiling temperatures, ensuring maximum life and reliable
braking power, even in extreme conditions. AMSOIL
Series 500 High-Performance DOT 3 Brake Fluid has
a dry ERBP of 274°C (525°F) and wet ERBP of
156°C (313°F). AMSOIL Series 600 DOT 4 Racing
Brake Fluid has a dry ERBP of 304°C (580°F)
and wet ERBP of 210°C (410°F).
a fluid is non-compressible it means it wont
compress into a smaller volume when pressure is applied.
In a brake system, fluid pressure is multiplied by
the master cylinder and can reach more than 1,000
pounds per square inch (psi) in the lines. Like any
other hydraulic fluid, brake fluid must be non-compressible
at the expected pressures to transmit force from one
end of the system to the other while simultaneously
lubricating the pistons and rubber parts as they move
through their bores. If the fluid were to compress,
all braking power would be lost. AMSOIL Series 500
High-Performance DOT 3 Brake Fluid remains non-compressible,
even at the highest pressures generated in automotive
brake systems. AMSOIL Brake Fluid provides superior
stopping ability under the most demanding conditions.
Brake Fluid Maintenance
Brake fluids fail either because
they boil or because they cease to provide adequate
lubrication and corrosion protection. Both reasons
for failure are the result of contamination, usually
by water or petroleum products.
DOT 3 and DOT 4 polyglycol ether-based
brake fluids are hygroscopic, which means they absorb
water easily and hold it in suspension, similar to
antifreeze. In most climates, moisture seeps into
the brake system continuously through the various
seals and microscopic pores of the flexible brake
lines. This seepage can accelerate as a vehicle ages
and theres almost no limit to how much water
the fluid can absorb. By the time brake fluid has
been in the system for three years, it can easily
reach its wet boiling point. Because this happens
gradually, most drivers wont discover the reduced
braking ability until its too late.
Many owners manuals recommend
changing brake fluid every 24 months to remove moisture.
Approximately half of all cars and light trucks in
the U.S. over 10 years old have never had the brake
fluid changed. In addition, powersports applications
such as motorcycles, ATVs and UTVs require routine
brake fluid changes as well.