weight NISSAN PATROL 1998 Y61 / 5.G Brake System Workshop Manual

9. Set down weight slowly over axle center so that sensor springlength becomes the same as when in loaded condition (Refer
to table below). Check rear brake pressure in the same way
described in step 7.
4-door rear disc brake
Unit: kPa (bar, kg/cm2, psi)
Sensor spring
length ``L''* mm (in) Front brake
pressure
4,904 (49.0, 50, 711) Front brake
pressure 9,807
(98.1, 100, 1,422)
Rear brake
pressure Without
weight 175.2 - 178.2
(6.90 - 7.02) 2,158 - 3,138
(21.58 - 31.38, 22.0 - 32.0,313 - 455) 3,629 - 4,609
(36.29 - 46.09, 37.0 - 47.0,526 - 668)
With
weight 193.6 - 196.6
(7.62 - 7.74) 2,746 - 4,707
(27.46 - 47.07, 28.0 - 48.0,398 - 683) 4,217 - 6,178
(42.17 - 61.78, 43.0 - 63.0,611 - 896)
*: Depressed brake pedal.
10. Bleed air after disconnecting the tool. Refer to ``Bleeding Brake System'', BR-4.
11. Install front LH tire.
REMOVAL AND INSTALLATION
CAUTION:
+ Re®ll with new brake ¯uid ``DOT 3''.
+ Be careful not to splash brake ¯uid on painted areas; it
may cause paint damage. If brake ¯uid is splashed on
painted areas, wash it away with water immediately.
+ Do not reuse Load Sensing Valve once it is disassembled.
+ Replace damaged Load Sensing Valve as an assembly.
+ When disassembling, apply multi-purpose grease to all rubbing
areas.
SBR378D
BRAKE HYDRAULIC LINE/CONTROL VALVE
Load Sensing Valve (Cont'd)
BR-8

G SENSOR
The G sensor senses deceleration during braking to determine whether the vehicle is being driven on a high
 road (asphalt road, etc.) or a low  road (snow-covered road, etc.). It then sends a signal to the ABS con-
trol unit.
The reed switch turns on when it is affected by a magnetic ®eld. During sudden deceleration (braking on a
high  road), the weight moves and the magnet in the weight moves away from the reed switch. The mag-
netic ®eld then diminishes and the reed switch turns off.
ABS ACTUATOR AND ELECTRIC UNIT
The ABS actuator and electric unit contains:
+An electric motor and pump
+ Two relays
+ Six solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
+ ABS control unit
This component controls the hydraulic circuit and increases, holds
or decreases hydraulic pressure to all or individual wheels. The
ABS actuator and electric unit are not disassemble.
ABS actuator operation
Inlet solenoid
valve Outlet solenoid
valve
Normal brake operation OFF (Open) OFF (Closed) Master cylinder brake ¯uid pressure is directly trans-
mitted to wheel cylinder via the inlet solenoid valve.
ABS operation Pressure hold ON (Closed) OFF (Closed)
Hydraulic circuit is shut off to hold the wheel cylinder
brake ¯uid pressure.
Pressure
decrease ON (Closed) ON (Open) Wheel cylinder brake ¯uid is sent to reservoir via the
outlet solenoid valve. Then it is pushed up to the
master cylinder by pump.
Pressure
increase OFF (Open) OFF (Closed) Master cylinder brake ¯uid pressure is transmitted to
wheel cylinder.
SBR189E
SBR176E
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)
BR-35