NISSAN PATROL 1998 Y61 / 5.G Brake System Owner's Guide

Removal
1. Disconnect harness connector.
2. Disconnect control cable from control lever and bracket.
3. Remove control lever and bracket.
4. Disconnect control cable from center brake and remove controlcable.
Inspection
1. Check control lever and ratchet for evidence of wear or otherdamage. Replace if necessary.
2. Check wires for evidence of discontinuity or other deterioration. Replace if necessary.
3. Check parts at each connection for deformation or damage. Replace if necessary.
4. Check warning lamp and switch. Replace if necessary.
SBR437A
SBR209E
PARKING CENTER BRAKE CONTROL
BR-29

Installation
1. Apply a coating of grease to sliding contact surfaces.
2. Insert clevis pin from left side.
3. After installation is completed, adjust entire system.
Adjustment
1. Pull control lever with speci®ed amount of force. Check leverstroke and ensure smooth operation.Number of notches :7-9
2. Bend parking brake warning lamp switchplate so that brake warning lamp comes on when ratchet at parking brake lever is
pulled notches and goes out when fully released.Number of notches: 2
SBR033A
SBR438A
PARKING CENTER BRAKE CONTROL
BR-30

Removal and Installation
WARNING:
Clean brake lining with a vacuum dust collector to minimize
the hazard of airborne particles or other materials.
CAUTION:
Make sure parking brake lever is released completely.
1. Release parking brake lever fully.
2. Remove rear propeller shaft and drum.
3. After removing shoe hold pin by rotating push retainer, removeleading shoe then remove trailing shoe.
Remove spring by rotating shoes in direction arrow.
4. Remove adjuster and return spring.
5. Disconnect parking brake cable from center brake lever.
Be careful not to damage parking brake cable when separat-
ing it.
6. Remove retainer ring with a suitable tool. Then separate cen- ter brake lever and brake shoe.
SBR251E
SBR180E
PARKING CENTER BRAKE
BR-31

When installing, measure brake drum inside diameter and diameter
of brake shoes. Check that the difference between diameters is the
correct shoe clearance.Shoe clearance:0.25 - 0.4 mm (0.0098 - 0.0157 in)
If necessary, adjust by rotating adjuster.
Inspection Ð Drum
Standard inner diameter: 203.2 mm (8 in)
Maximum inner diameter: 204.5 mm (8.05 in)
Out-of-roundness (Ellipticity): 0.03 mm (0.0012 in) or less
Radial runout (Total indicator reading): 0.05 mm (0.0020 in) or less
+ Contact surface should be ®ne®nished with No. 120 to 150
emery paper.
+ Using a drum lathe, lathe brake drum if it shows scoring, par-
tial wear or stepped wear.
+ After brake drum has been completely reconditioned or
replaced, check drum and shoes for proper contact pattern.
Inspection Ð Lining
+Check lining thickness.
Lining wear limit: 1.5 mm (0.059 in)
Lining standard thickness: 5.1 mm (0.201 in)
Before installing new shoes, rotate nut until adjuster rod is at its
shortest point.
After installation, adjust shoe-to-drum clearance. Refer to Removal
and Installation.
SBR367A
SBR095A
SBR021A
PARKING CENTER BRAKE
Removal and Installation (Cont'd)
BR-32

Purpose
The Anti-Lock Brake System (ABS) consists of electronic and hydraulic components. It allows for control of
braking force so locking of the wheels can be avoided.
The ABS:
1) Improves proper tracking performance through steering wheel operation.
2) Eases obstacle avoidance through steering wheel operation.
3) Improves vehicle stability.
Operation
+When the vehicle speed is less than 10 km/h (6 MPH) this system does not work.
+ The Anti-Lock Brake System (ABS) has a self-test function. The system turns on the ABS warning lamp
for 1 second each time the ignition switch is turned ``ON''. After the engine is started, the ABS warning
lamp turns off. The system performs a test the ®rst time the vehicle reaches 6 km/h (4 MPH). A mechani-
cal noise may be heard as the ABS performs this self-test. This is a normal part of the self-test feature. If
a malfunction is found during this check, the ABS warning lamp will stay on.
+ While driving, a mechanical noise may be heard during ABS operation. This is a normal condition.
+ While DIFF-LOCK is on, the anti-lock brake warning light ¯ashes. This indicates that anti-lock may not be
fully operated. (ABS only)
ABS Hydraulic Circuit
j1Inlet solenoid valve
j
2Outlet solenoid valve
j
3Reservoir j
4Pump
j
5Motor
j
6Inlet valve j
7Outlet valve
j
8Bypass check valve
j
9Damper
SBR211E
ANTI-LOCK BRAKE SYSTEM
BR-33

System Components
System Description
WHEEL SENSOR
The sensor unit consists of a gear-shaped sensor rotor and a sen-
sor element. The element contains a bar magnet around which a
coil is wound. The sensor is installed on the back of the brake rotor.
As the wheel rotates, the sensor generates a sine-wave pattern.
The frequency and voltage increase(s) as the rotating speed
increases.
CONTROL UNIT (built in ABS actuator and electric unit)
The control unit computes the wheel rotating speed by the signal
current sent from the sensor. Then it supplies a DC current to the
actuator solenoid valve. It also controls ON-OFF operation of the
valve relay and motor relay. If any electrical malfunction should be
detected in the system, the control unit causes the warning lamp
to light up. In this condition, the ABS will be deactivated by the
control unit, and the vehicle's brake system reverts to normal
operation. (For control unit layout, refer to ABS ACTUATOR AND
ELECTRIC UNIT, BR-34.)
SBR185E
SBR186E
ANTI-LOCK BRAKE SYSTEM
BR-34

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

Removal and Installation
CAUTION:
Be careful not to damage sensor edge and sensor rotor teeth.
When removing the front wheel hub or rear axle shaft
assembly, disconnect the ABS wheel sensor from the assem-
bly and move it away.
FRONT WHEEL SENSOR
SBR187E
ANTI-LOCK BRAKE SYSTEM
BR-36

REAR WHEEL SENSOR
G SENSOR
Always replace G sensor if bumped or dropped. Otherwise,
performance characteristics of G sensor will be changed,
which in turn changes ABS control performance characteris-
tics.
SBR188E
SBR190E
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)BR-37

ABS ACTUATOR AND ELECTRIC UNIT
Removal
1. Disconnect battery cable.
2. Drain brake ¯uid. Refer to ``Changing Brake Fluid'', BR-3.
3. Remove mounting bracket ®xing bolts and nuts.
4. Disconnect connector, brake pipes and remove ®xing nuts.
Installation
CAUTION:
After installation, re®ll brake ¯uid. Then bleed air. Refer to
Bleeding Brake System'', BR-4.
1. Connect brake pipes temporarily.
2. Tighten ®xing bolts and nuts.
3. Tighten brake pipes.
4. Connect connector and battery cable.
SBR191E
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)BR-38