Chassis; Bleeding The Hydraulic Brake System (Abs) - Yamaha FZ 25 2021 Supplementary Service Manual

EAS20024

CHASSIS

EAS30893
BLEEDING THE HYDRAULIC BRAKE
SYSTEM (ABS)
EWA13100
WARNING
Always bleed the brake system when the
brake related parts are removed.
ECA18050
NOTICE
• Bleed the brake system in the following or-
der.
• 1st step: Front brake calipers
• 2nd step: Rear brake caliper
EWA15740
WARNING
Bleed the ABS whenever:
• the system is disassembled.
• a brake hose is loosened, disconnected or
replaced.
• the brake fluid level is very low.
• brake operation is faulty.
TIP
• 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 fluid
before applying the brake. Ignoring this pre-
caution could allow air to enter the hydraulic
brake system, considerably lengthening 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:
• ABS
a. Fill the brake fluid reservoir to the proper
level with the specified brake fluid.
b. Install the diaphragm (brake master cylin-
der reservoir or brake fluid reservoir).
c. Connect a clear plastic hose "1" tightly to
the bleed screw "2".

CHASSIS

A
B
A. Front
B. Rear
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 posi-
tion.
g. Loosen the bleed screw.
TIP
Loosening the bleed screw will release the pres-
sure and cause the brake lever to contact the
throttle grip or the brake pedal to fully extend.
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. Check the operation of the hydraulic unit.
Refer to "HYDRAULIC UNIT OPERA-
TION TESTS" on page 4-26.
3-7
CHK
ADJ