Polaris Sportsman 450 Owner's Manual page 85

MAINTENANCE AND LUBRICATION
Brakes
The front and rear brakes are hydraulic disc brakes, activated by
moving the single brake lever toward the handlebar. These brakes are
self-adjusting.
The following checks are recommended to keep the brake system in
good operating condition. Check more often if brakes are used heavily
under normal operation.
WARNING
Never store or use a partial bottle of brake fluid. Brake fluid is
hygroscopic, meaning it rapidly absorbs moisture from the air.
The moisture causes the boiling temperature of the brake fluid to
drop, which can lead to early brake fade and the possibility of
accident or severe injury. After opening a bottle of brake fluid,
always discard any unused portion.
1. Always keep brake fluid at an adequate level (see page 34).
WARNING
An over-full master cylinder may cause brake drag or brake
lock-up, which could result in serious injury or death. Maintain
brake fluid at the recommended level. Do not overfill.
NOTE: Under normal operation, the diaphragm extends into the
reservoir as fluid level drops. If the fluid level is low and the
diaphragm is not extended, a leak is likely and the diaphragm
should be replaced. Always fill the reservoir as needed
whenever the cover is loosened or removed to ensure proper
diaphragm operation. Use Polaris DOT 3 brake fluid. Do not
overfill.
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