Yamaha XP500, Service Manual

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GEN
INFO
FEATURES
• Emergency braking (ABS activated)
1) Depressurized state
When the front wheel is about to lockup, port D
A
of the solenoid valve is opened by the “depres-
surization” signal transmitted from the ECU (ABS). When this occurs, the spool of the flow control
valve compresses the return spring to close port B
9
. Brake fluid that has entered through port A
7
is restricted by the orifice
0
and the brake fluid is sent to the brake caliper via port C
C
and
port D
A
, and the buffer chamber. As a result, the hydraulic pressure in the brake caliper is
reduced.
The brake fluid stored in the buffer chamber is pumped back to the brake master cylinder by the
fluid pressure pump linked to the pump motor.
1
Brake master cyl-
inder
2
Brake light switch
3
ABS motor
4
Pump
5
Buffer chamber
6
Flow control valve
7
Port A
8
Spool
9
Port B
0
Orifice
A
Port D
B
Solenoid valve
C
Port C
D
Brake caliper
E
ECU (ABS)
F
ABS warning light
G
Brake fluid pres-
sure
H
Time
I
Repressurizing