Polaris 850 PRO-RMK 155 2.6" QD 2021, Manual

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9850060 R02 - 2020-2021 850 AXYS™ Long Track Snowmobile Service Manual
© Copyright Polaris Inc.
6.35
BRAKE SYSTEM
BRAKE SYSTEM GENERAL NOTES
WARNING
An unsafe condition exists when air is trapped in the
hydraulic brake system. Air in the brake hydraulic
system acts like a soft spring and absorbs a large
percentage of the pressure developed by the master
cylinder. Without this pressure, the braking system
cannot develop full braking force to allow for safe,
controlled stops. It is extremely important to bleed the
brakes properly after any brake system work has been
performed or when inspection reveals spongy brakes.A
soft, spongy feeling in the brake lever and/or brake
pedal could indicate a hazardous condition in the brake
system. Do not operate the vehicle until the failure in
the brake system is corrected.Keep brake fluid tightly
sealed and out of reach of children. Brake fluid can
accumulate moisture, reducing its effectiveness.
Contaminated brake discs or brake pads greatly reduce
braking performance and increase stopping distance.
Do not attempt to clean contaminated pads. Replace
them. Clean the brake disc with brake cleaner.This
brake system requires ethylene-glycol based fluid (DOT
4). Do not use or mix different types of fluid such as
silicone-based or petroleum-based.Do not use brake
fluid taken from old, used or unsealed containers.
Never reuse brake fluid.
IMPORTANT
Pressure bleeding is not recommended. When fluid
surges through the fittings, it is possible to cavitate the
fluid and create air in the system. In addition, the fluid
stored in a pressure bleeder may be contaminated.
Always use fresh DOT 4 brake fluid from a sealed
container.
Keep these points in mind when bleeding hydraulic
brakes:
• The master cylinder reservoirs have limited capacities.
It is easy to empty them during the bleeding
procedure. This introduces air into the system which
you are trying to purge. Watch the reservoir closely
and add fluid when necessary to prevent air from
entering the system.
• Apply only light to moderate pressure to the lever or
pedal when bleeding the brake system. Extreme
pressure will cause a surge of fluid through the small
orifices of the brake system when the bleeder screw is
opened and introduce air into the system by means of
cavitation.
• Small amounts of air can become trapped in the banjo
bolt fittings at the master cylinder(s) and junction
points of brake lines. These fittings can be purged of
air by following a standard bleeding procedure at these
fittings (instead of the bleed screw on caliper) if
necessary to speed the bleeding process. This is
usually only needed if system was completely drained
of fluid. Bleed each line connection, starting with the
fitting closest to the master cylinder, working toward
the caliper, and ending with the bleed screw.
• Always torque banjo bolts and other brake system
fittings to specified torque.
• Change fluid every 2 years, or when fluid is dark or
contamination is suspected.
BRAKE SYSTEM INSPECTION
BRAKE LEVER TRAVEL
Inspect brake lever travel before each use of the
snowmobile.
Squeeze the brake lever. It should move no closer to the
hand grip than .5″ (1.3 cm)
q
. A smaller distance
indicates low brake fluid level or air in the hydraulic
system.
BRAKE LEVER FEEL
If the brake lever feels “spongy” when squeezed, check
the brake fluid level and condition.
WARNING
Continued use of “spongy” brakes may cause a
complete loss of brakes, which could result in serious
injury or death. Always have the brakes serviced at the
first sign of spongiest.
FINAL DRIVE / BRAKE SYSTEMS