Bleeding The Hydraulic Brake System - Yamaha MT-03 Service Manual

EAS00134
BLEEDING THE HYDRAULIC BRAKE
SYSTEM
WARNING
Bleed the hydraulic brake system when-
ever:
• the system is disassembled
• a brake hose is loosened, disconnected or
replaced
• the brake fluid level is very low
• brake operation is faulty.
NOTE:
• Be careful not to spill any brake fluid or allow
the brake master cylinder reservoir or brake
fluid reservoir to overflow.
• When bleeding the hydraulic brake system,
make sure there is always enough brake flu-
id before applying the brake. Ignoring this
precaution could allow air to enter the hy-
draulic brake system, considerably lengthen-
ing the bleeding procedure.
• If bleeding is difficult, it may be necessary to
let the brake fluid settle for a few hours.
Repeat the bleeding procedure when the tiny
bubbles in the hose have disappeared.
1. Bleed:
• Hydraulic brake system
a. Fill the brake fluid reservoir to the proper
level with the recommended brake fluid.
b. Install the diaphragm (brake master cylinder
reservoir or brake fluid reservoir).
c. Connect a clear plastic hose "1" tightly to
the bleed screw.
A. Front brakes
B. Rear brake
A
B
d. Place the other end of the hose into a con-
tainer.
e. Slowly apply the brake several times.
f. Fully pull the brake lever or fully press down
the brake pedal and hold it in position.
g. Loosen the bleed screw.
NOTE:
Loosening the bleed screw will release the
pressure and cause the brake lever to contact
the throttle grip or the brake pedal to fully ex-
tend.
h. Tighten the bleed screw, and then release
the brake lever or brake pedal.
i. Repeat steps (e) to (h) until all of the air
bubbles have disappeared from the brake
fluid in the plastic hose.
j. Tighten the bleed screw to the specified
torque.
Bleed screw
6 Nm (0.6 m·kg, 4.3 ft·lb)
(front brake)
14 Nm (1.4 m·kg, 10 ft·lb)
(rear brake)
k. Fill the brake fluid reservoir to the proper
level with the recommended brake fluid.
Refer to "CHECKING THE BRAKE FLUID
LEVEL" on page 3-19.
WARNING
After bleeding the hydraulic brake system,
check the brake operation.
3-21
CHASSIS