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Snowmobile Polaris 2006 - 2007 FS / FST. Manual - part 40

7.7

Final Drive and Brake Systems

Rev. 1 07/2006

Chaincase Component Inspections

Inspect gears and chain for missing teeth, or abnormal
wear.

Inspect and measure the shift fork assembly.

Inspect the chaincase oil seals for nicks or other damage.
Replace seals if damage is found.

Inspect the indicator hub face and tensioner pad for
abnormal wear.

BRAKE DISC

SNAP RING

OIL SEAL

UPPER HUB CARRIER

SHIFT SHAFT

INDICATOR HUB

SNAP RING

SPACER

WASHER

WEAR PAD

TENSIONER PAD

LOWER HUB CARRIER

SNAP RING

SHIFT FORK

WASHER

PINION GEAR

RVS GEAR

SPUR GEAR

= In. / mm.

Shift Fork Minimum Thickness Service Limit

.135

″ (3.34mm)

7.8

Final Drive and Brake Systems

Rev. 1 07/2006

JACKSHAFT / DRIVESHAFT

Jackshaft Removal

Remove the belt, and driven clutch.

Reference the chaincase disassembly procedures in this
chapter, and remove the following components:

• Chaincase Cover

• Shift Fork Assembly

• Pinion Gear

• Upper Sprocket Snap Ring

Remove the jackshaft bearing retainer.

Extract the jackshaft from the clutch-side.

Jackshaft Installation

Reverse of removal procedure.

Driveshaft Removal

Remove the belt, and the driven clutch.

Remove the speed sensor housing.

Using a track stand or similar device, raise the track up and
off the ground.

Loosen the rear idler adjustment screws and idler shaft
screws. Dis-engage the rear suspension torsion springs.

Remove enough track tension on the drive shaft as possible.

Slide the driveshaft towards the clutch-side of the
snowmobile until the end of the driveshaft drops out of the
chaincase. Remove the driveshaft from the snowmobile.

Driveshaft Installation

Reverse of removal procedure.

7.9

Final Drive and Brake Systems

Rev. 1 07/2006

BRAKE SYSTEM

Overview

The hydraulic brake system consists of the following
components or assemblies: brake lever, master cylinder,
hydraulic hose, brake caliper (slave cylinder), brake pads, and a
brake disc.

When the hand activated brake lever is applied, it contacts a
piston within the master cylinder. As the master cylinder piston
moves inward it closes a small opening called a 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 caliper move toward the disc and
applies pressure to the moveable brake pads. As the lever
pressure is increased, the braking effect is increased.

The friction applied to the brake pads will cause the pads to
wear. As the pads wear, the piston within the caliper self-adjusts
and moves further outward.

Brake fluid level is critical to proper system operation. A low
fluid level allows air to enter the system causing the brakes to
feel spongy.

Compensation Port

Located within the master cylinder is a small compensating port
which is opened and closed by the master cylinder piston
assembly. The port is open when the brake lever is released and
the piston is outward. As the temperature within the hydraulic
system changes, this port compensates for fluid expansion
caused by heat, or contraction caused by cooling. During system
service, be sure this port is open. 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 the brake fluid to expand. Master cylinder reservoirs
should be filled to the top of the fluid level mark on the inside
of the reservoir, 1/4” - 5/16” (.6 -.8 cm) below lip of reservoir
opening.

This system also incorporates a diaphragm as part of the cover
gasket and a vent port located between the gasket and the cover.
The combination diaphragm and vent allow for the air above the
fluid to equalize pressure as the fluid expands or contracts. Be
sure the vent is open and allowed to function. If the reservoir is
overfilled or the diaphragm vent is plugged, the expanding fluid
may build pressure in the brake system and lead to brake failure.

GENERAL GUIDELINES

Keep these points in mind when bleeding hydraulic brakes:

• The master cylinder reservoirs have limited capacities.

It is easy to empty them during the bleeding procedure.
This introduces air into the system which you are trying
to purge. Watch the reservoir closely and add fluid
when necessary to prevent air from entering the system.

• Apply only light to moderate pressure to the lever or

pedal when bleeding the brake system. Extreme
pressure will cause a surge of fluid through the small
orifices of the brake system when the bleeder screw is
opened and introduce air into the system by means of
cavitation.

WARNING

Contaminated brake discs or brake pads greatly reduce

braking performance and increase stopping distance.

Do not attempt to clean contaminated pads. Replace

them. clean the brake disc with brake cleaner.

Only use DOT 4 brake fluid. Never mix different types

of brake fluids.

Never re-use brake fluid or fluid from an old, opened

container.

Keep brake fluid in a tightly-sealed container and out of

the reach of children. Brake fluid can absorb moisture,

reducing its effectiveness.

A soft, spongy-feeling in the brake lever may indicate a

hazardous condition within the brake system. Do not

operate the snowmobile until the problem in the system

is corrected.

An unsafe condition exists when air trapped in the

hydraulic brake system. Air in the brake hydraulic

system acts like a spring and absorbs a large

percentage of the pressure developed by the master

cylinder. Without this pressure, the braking system

cannot develop full braking force to allow for safe,

controlled stops. It is extremely important to bleed the

brakes properly after any brake system work has been

performed or when inspection reveals spongy brakes.

CAUTION

Pressure bleeding is not recommended. When fluid
surges through the fittings, it is possible to cavitate the
fluid and create air in the system. In addition, the fluid
stored in a pressure bleeder may be contaminated. Al-
ways use fresh DOT 4 brake fluid from a sealed con-
tainer.

7.10

Final Drive and Brake Systems

Rev. 1 07/2006

• Small amounts of air can become trapped in the banjo

bolt fittings at the master cylinder(s) and junction points
of brake lines. These fittings can be purged of air by
following a standard bleeding procedure at these
fittings (instead of the bleed screw on caliper) if
necessary to speed the bleeding process. This is usually
only needed if system was completely drained of fluid.
Bleed each line connection, starting with the fitting
closest to the master cylinder, working toward the
caliper, and ending with the bleed screw.

• Always torque banjo bolts and other brake system

fittings to specified torque.

• Change fluid every 2 years, or when fluid is dark or

contamination is suspected.

BRAKE FLUID REPLACEMENT & BLEEDING

NOTE: This procedure should be used to change
fluid or bleed brakes during regular maintenance, or
after complete brake service. Brake fluid may
damage painted or plastic surfaces. Take care not to
spill, and wipe up any spills immediately. Cover
parts to avoid damage.

Clean the reservoir cover.

Remove the two T-15 Torx screws from the cover.

Carefully remove the cover and diaphragm assembly from
the reservoir.

Under the cover, inspect the vent slots under the bellows
and remove any debris or blockage.

Bleed or replace the fluid by attaching a clear hose from the
caliper bleeder fitting to a clean container. Be sure the hose
fits tightly on the bleeder fitting.

Pump the brake lever a few times and hold.

Slowly open the bleeder fitting and let the old fluid or air
escape. You will feel the lever release as you let the fluid
or air escape. Close the bleeder fitting.

Pump the brake lever a few times and hold it again.

Repeat steps 7 and 8 until you see new brake fluid coming

from the caliper bleeder fitting or if you are bleeding the
air, repeat this step until you see only fluid coming out. This
may take several intervals.

10. Torque the bleeder screw to 8-11 ft.-lb. (11-15Nm).

11. When adding fluid, add DOT 4 brake fluid to 1/4-5/16” (.6-

.8 cm) from the reservoir top.

12. Install cover and diaphragm assembly.

13. Tighten the cover screws to 16-20 in-lb. (1.8-2.3Nm).

14. Field test machine before putting into service. Check for

proper braking action and lever reserve. Lever reserve is
when the lever is firmly applied, the lever reserve should
be no less than 1/2” (1.3 cm) from the handlebar.

15. Verify that the sight glass indicates a full reservoir.

16. Check brake system for any fluid leaks.

BRAKE LINE REPLACEMENT

Follow these steps if the brake line is to be replaced.

If needed bleed the brake system by attaching a clear hose
to the caliper bleed fitting.

Attach the other end to a Mity Vac or similar vacuum tool.

Bleed the system of brake fluid.

144-192 in-lb. (16.2-21.6Nm)

brake light switch

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