Brake System Service; Brake System Operation Overview; Brake Bleeding / Fluid Change - Polaris GENERAL 2016 Service Manual

BRAKE SYSTEM SERVICE

BRAKE SYSTEM OPERATION OVERVIEW

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.
9929375 R02 - 2016-2019 GENERAL / GENERAL 4 Service Manual
© Copyright Polaris Industries Inc.

BRAKE BLEEDING / FLUID CHANGE

IMPORTANT
When bleeding the brakes or replacing the fluid always
start with the furthest caliper from the master cylinder.
This procedure should be used to change fluid or bleed
brakes during regular maintenance.
CAUTION
Always wear safety glasses when handling chemicals
and fluids.
CAUTION
Brake fluid will damage finished surfaces. Do not allow
brake fluid to come in contact with finished surfaces.
1. Clean master cylinder reservoir cover thoroughly and
remove the cover.
2. If changing fluid, remove old fluid from reservoir with
a Mity Vac™ pump (2870975) or similar tool.
3. Add brake fluid to the indicated MAX level of
reservoir.
Polaris DOT 4 Brake Fluid
(PN 2872189)
4. Begin bleeding procedure with the caliper that is
farthest from the master cylinder. Install a box end
wrench on caliper bleeder screw. Attach a clean,
clear hose to fitting and place the other end in a clean
container. Be sure the hose fits tightly on fitting.
5. Have an assistant slowly pump foot pedal until
pressure builds and holds.
BRAKE SYSTEM
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