Polaris ACE 900 2017 Service Manual page 407

BRAKE SYSTEM TROUBLESHOOTING
BRAKE NOISE TROUBLESHOOTING
Dirt or dust buildup on the brake pads and disc is the most common cause of brake noise (squeal caused by vibration).
If cleaning does not reduce the occurrence of brake noise, Permatex™ Disc Brake Quiet can be applied to the back of
the pads. Follow directions on the package. This will keep pads in contact with caliper piston(s) to reduce the chance
of squeaks caused by dirt or dust.
BRAKE NOISE TROUBLESHOOTING
POSSIBLE CAUSE
Dirt, dust, or imbedded material on pads or disc
Pad(s) dragging on disc (noise or premature pad wear) because of
improper adjustment
Master cylinder reservoir overfilled
Master cylinder compensating port restricted
Master cylinder piston not returning completely
Caliper piston(s) not returning
Operator error (riding the brake)
Loose wheel hub or bearings
Brake disc warped or excessively worn
Brake disc misaligned or loose
Noise is from other source (axle, hub, disc or wheel)
Wrong pad for conditions
BRAKES SQUEAL / POOR BRAKE
PERFORMANCE
• Air in system
• Water in system (brake fluid contaminated)
• Caliper or disc misaligned
• Caliper dirty or damaged
• Brake line damaged or lining ruptured
• Worn disc and/or friction pads
• Incorrectly adjusted stationary pad
• Worn or damaged master cylinder or components
• Damaged break pad noise insulator
• Brake pads dragging
• Brake caliper dragging
PEDAL VIBRATION
• Disc damaged
• Disc worn (runout or thickness variance exceeds serv-
ice limit)
9929422 R02 - 2017-2019 ACE 900 Service Manual
© Copyright Polaris Industries Inc.
REMEDY
Spray disc and pads with CRC Brakeleen™ or an equivalent non-
flammable aerosol brake cleaner. Remove pads and/or disc hub to
clean imbedded material from disc or pads.
Adjust pad stop (front calipers)
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
CALIPER OVERHEATS (BRAKES DRAG)
• Compensating port plugged
• Pad clearance set incorrectly
• Brake pedal binding or unable to return fully
• Residue build up under caliper seals
• Operator riding brakes
BRAKES LOCK
• Alignment of caliper to disc
• Caliper pistons sticking
• Improper assembly of brake system components
BRAKE SYSTEM
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