34
1
Rear master
cylinder
2
Hydraulic unit
3
Silencer chamber
4
Hydraulic pump
5
Electric motor
6
Buffer chamber
7
Hydraulic control
valve
8
Front master
cylinder
9
Rear brake
caliper
10
Front brake caliper
11
Electronic control unit
12
Rear wheel sensor
13
Front wheel sensor
14
ABS warning light
ANTI-LOCK BRAKE SYSTEM (ABS)
CHAS
HYDRAULIC UNIT (HU)
Hydraulic unit is composed of two pieces of hydraulic control valve (solenoid valve, flow control valve), buff-
er chamber, pump and silencer chamber, and one motor. It adjusts the front/rear wheel brake fluid pressure
to control the wheel rotation condition according to the signal transmitted from the electronic control unit.
HU components
Components of each system are five parts as fol-
lows.
1
Flow control valve
2
Solenoid valve
3
Buffer chamber
4
Hydraulic pump
5
Silencer chamber
Flow control valve 1 works to keep the brake fluid
flow at a constant flow rate while the ABS works.
This valve also increases and decreases the
brake fluid pressure together with the solenoid
valve 2 .
Buffer chamber 3 accumulates the decom-
pressed brake fluid temporarily while the ABS
works.
Hydraulic pump 4 is driven by the motor and it re-
turns the brake fluid which has been stored in the
buffer chamber 3 to the master cylinder side line.
In addition, to increase the quietness, the silencer
chamber 5 is equipped.
6
Brake master cylinder
7
Brake caliper
8
ABS warning light
9
ECU
