Yamaha 2007 XP500 Service Manual page 22

Emergency braking (ABS activated)
G
1.Depressurized state
When the front wheel is about to lockup, port D "11" 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 "10" and the brake fluid is sent to the brake caliper via port C "13" and
port D "11", and the buffer chamber. As a result, the hydraulic pressure in the brake caliper is re-
duced.
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 cylinder
2. Brake light switch
3. ABS motor
4. Pump
5. Buffer chamber
6. Flow control valve
7. Port A
8. Spool
9. Port B
10. Orifice
11. Port D
12. Solenoid valve
13. Port C
14. Brake caliper
15. ECU (ABS)
16. ABS warning light
17. Brake fluid pressure
18. Time
19. Repressurizing
1-13
FEATURES