
BRAKES
8-5
FRONT BRAKES
The front brake system consists of the following components or assemblies: brake lever; master cylinder; hydraulic hose;
brake calipers (slave cylinder); brake pads; and brake discs, which are secured to the drive line.
When the hand activated brake lever (A) is applied it contacts a piston (B) within the master cylinder. As the master
cylinder piston moves inward it closes a small opening (compensating port) (C) within the cylinder and starts to build
pressure within the brake system. As the pressure within the system is increased, the piston (D) located in the brake
caliper moves outward and applies pressure to the moveable brake pad. This pad contacts the brake disc and moves the
caliper in its floating bracket, pulling the stationary side pad into the brake disc. The resulting friction reduces brake disc
and vehicle speed. As the lever pressure is increased, the braking affect is also increased.
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 (C), which is opened and closed by the master cylinder piston
assembly. The port is open when the lever is released and the master cylinder piston is outward. As the temperature within
the hydraulic system changes, this port compensates for fluid expansion (heated fluid) or contraction (cooled fluid). 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 fluid expansion. Never overfill the
reservoir! Fill to 0.64 - 0.80 cm (1/4
〃
- 5/16
〃
) from top of the cylinder.
This system also incorporates a diaphragm (E) as part of the cover gasket; and a vent port (F) 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. Make sure the vent is open and allowed to function. If the reservoir is over filled or the diaphragm
vent is plugged the expanding fluid may build pressure in the brake system leading to brake failure.
When servicing brake systems use only DOT 4 High Temperature Brake Fluid.
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. DOT 4 Brake fluids is hygroscopic, meaning it rapidly absorbs
moisture. This causes the boiling temperature of the brake fluid to drop, which can lead to brake fade and
possible loss of control.
Summary of Contents for AT56-69E
Page 35: ...MAINTENANCE 2 25 ...
Page 45: ...CVT SYSTEM 3 4 CVT EXPLODED VIEW ...
Page 56: ...ENGINE 4 3 ENGINE ILLUSTRATION ENGINE EXPLODED VIEW ...
Page 57: ...ENGINE 4 4 ...
Page 58: ...ENGINE 4 5 COOLING SYSTEM EXPLODED VIEW ...
Page 59: ...ENGINE 4 6 OIL FLOW DIAGRAM ...
Page 125: ...FUEL AND CARBURETOR 6 15 FUEL TANK SYSTEM ...
Page 135: ...BODY SUSPENSION STEERING 7 6 SUSPENSION ...
Page 142: ...BODY SUSPENSION STEERING 7 13 STEERING ...
Page 151: ...BRAKES 8 6 FRONT BRAKE EXPLODED VIEW MASTER CYLINDER ...
Page 196: ...ELECTRICAL 9 31 WIRE DIAGRAM ...