Aeon 350cc, Service Manual

Page: 147 / 192

BODY FRAME
6-147
HYDRAULIC BRAKE SYSTEM OPERATION
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 hand 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 brake systems use DOT3 or DOT 4 Brake
Fluid.
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. The
brake fluid is hygroscopic and it means that it rapidly
absorbs moisture. This causes the boiling temperature of
the brake fluid to drop, which can lead to early break fade
and the possibility of serious injury.
BRAKE NOISE TROUBLESHOOTING
Dirt, dust, or imbedded material on pads or disc.
Spray disc and pads with CRC Brakeleen™ or same equivalent
non-flammable aerosol brake cleaner. Remove pads and/or
disc hub to clean imbedded material from disc or pads.
Pad(s) dragging on disc (noise or premature pad wear)
because of improper adjustment.
Adjust pad stop (front calipers)
Master cylinder reservoir overfilled.
Set to proper level
Master cylinder compensating port restricted.
Clean compensating port
Master cylinder piston not returning completely.
Inspect. Repair as necessary
Caliper piston(s) not returning.
Clean piston(s) seal
Operator error (riding the brake).
Educate operator
Loose wheel hub or bearings.
Check wheel and hub for abnormal movement.
Brake disc warped or excessively worn
Replace disc
Brake disc misaligned or loose
Inspect and repair as necessary
Noise is from other source (axle, hub, disc or wheel).
If noise does not change when brake is applied check other
sources. Inspect and repair as necessary
Wrong pad for conditions
Change to a softer or harder pad
Brake System Inspection