Service Manual

9.4
BRAKES
HYDRAULIC BRAKE SYSTEM OPERATION
The Polaris brake system consists of the following components
or assemblies: brake pedal, master cylinder, hydraulic brake
lines, brake calipers, brake pads, and brake discs, which are
secured to the drive line.
When the foot activated brake lever is applied it applies pressure
on the piston within the master cylinder. As the master cylinder
piston moves inward it closes a small opening (compensating
port) within the cylinder and starts to build pressure within the
brake system. As the pressure within the system is increased,
the pistons located in the brake calipers move outward and apply
pressure to the moveable brake pads. These pads contact the
brake discs and move the calipers in their floating bracket,
pulling the stationary side pads into the brake discs. The
resulting friction reduces brake disc and vehicle speed.
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 master cylinder is the compensating port
which is opened and closed by the master cylinder piston
assembly. As the temperature within the hydraulic system
changes, this port compensates for fluid expansion or
contraction. Due to the high temperatures created within the
system during heavy braking, it is very important that the master
cylinder reservoir have adequate space to allow for fluid
expansion. Never overfill the reservoir! Do not fill the
reservoir beyond the MAX LEVEL line!
When servicing Polaris brake systems use only Polaris DOT 4
Brake Fluid (PN 2872189). WARNING: Once a bottle is
opened, use what is necessary and discard the rest in accordance
with local laws. Do not store or use a partial bottle of brake fluid.
Brake fluid is hygroscopic, meaning it rapidly absorbs moisture.
This causes the boiling temperature of the brake fluid to drop,
which can lead to early brake fade and the possibility of serious
injury.
BRAKE SYSTEM EXPLODED VIEW
Caliper Banjo Style Fittings:
15 ft. lbs. (20 Nm).
All Caliper Bleed Screws:
47 in. lbs. (5.3 Nm)
Master Cylinder Side View
Cross
MC Rear
Brake Line
RH Rear Line
RH Rear Caliper
RH Front
Brake Line
RH Front Caliper
Brake
Master Cylinder
LH Front
LH Rear Caliper
LH Front Caliper
Brake Line
LH Rear Line
1
2
1
1
2
2
1
3
All Flare Style Fittings:
12-15 ft. lbs. (16-20 Nm)
3
1
1
2
2
15 ft. lbs.
(20 Nm)
3
Fitting
Switch