Polaris 2005 SPORTSMAN 500 Servise Manual page 242

BRAKES
Brake Noise Troubleshooting
Possible Cause
Dirt, dust, or im-
bedded material with CRC Brake Kleent
on pads or disc
Pad(s) dragging on
disc (noise or
premature pad wear)
Improper adjustment
Insufficient lever or
pedal clearance
Master cylinder res-
ervoir overfilled
Master cylinder
compensating port
restricted
Master cylinder pis-
ton not returning com-
pletely
Caliper piston(s) not
returning
Operator error (riding
the brake / park brake
applied)
Loose wheel hub or
bearings
Brake disc warped or
excessively worn
Brake disc
misaligned or loose
Noise is from other
source (chain, axle,
hub, disc or wheel)
Wrong pad for
conditions
9.6
Remedy
Spray disc and pads
or equivalent non-flam-
mable aerosol brake
cleaner. Remove pads
and/or disc hub to clean
imbedded material from
disc or pads.
Adjust pad stop
(front calipers)
Check position of
controls & switches.
Set to proper level
Clean compensating port
Inspect.
Repair as necessary
Clean piston(s) seal
Educate operator
Check wheel and hub
for abnormal
movement.
Replace disc
Inspect and repair as
necessary
If noise does not
change when brake is
applied check other
sources. Inspect and
repair as necessary
Change to a softer or
harder pad
HYDRAULIC BRAKE SYSTEM
OPERATION OVERVIEW
Typical Hydraulic Brake System
Must be clear
to allow
proper dia-
phragm move-
ment
F
B
A
Move-
able
Brake
Pad G
The Polaris disc brake system consists of the
following components or assemblies: brake lever;
master cylinder; hydraulic hose; brake calipers (slave
cylinder); brake pads; and brake discs, which are
secured to the drive line.
When the hand activated brake lever (A) is applied it
contacts piston (B) within the master cylinder. As the
master cylinder piston moves inward it closes a small
opening (compensating port C) within the cylinder and
starts to build pressure within the brake system. As
the pressure within the system is increased, the piston
(D) located in the brake caliper moves outward and
applies pressure to the brake pad. This pad contacts
the brake disc and moves the caliper in its floating
bracket, pulling the stationary side pad into the brake
disc. The resulting friction reduces brake disc and
vehicle speed. As the lever pressure is increased, the
braking affect is also increased.
The friction applied to the brake pads will cause the
pads to wear. As these pads wear, the piston within
the caliper moves further outward and becomes self
adjusting. Fluid from the reservoir fills the additional
area created when the caliper piston moves outward.
Brake fluid level is critical to proper system operation.
Too little fluid will allow air to enter the system and
cause the brakes to feel spongy. Too much fluid could
cause brakes to drag due to fluid expansion.
Located within the
compensating port (C) which is opened and closed by
the master cylinder piston assembly. The port is open
Compensating port
E compensates
for temperature
changes by allow-
ing fluid back to
C
master cylinder
D
master cylinder is the