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

Ground Circuit Check ................................................56
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC
ITEMS ........................................................................\
.....57
Diagnostic Procedure 1 (Wheel sensor or rotor) ......57
Diagnostic Procedure 2 (ABS actuator solenoid
valve and solenoid valve relay) .................................59
Diagnostic Procedure 3 (Motor relay or motor).........61
Diagnostic Procedure 4 (Low voltage) ......................63
Diagnostic Procedure 5 (G sensor) ...........................64
Diagnostic Procedure 6 (Control unit) .......................65
TROUBLE DIAGNOSES FOR SYMPTOMS .................66
Diagnostic Procedure 7 (ABS works frequently.) ......66
Diagnostic Procedure 8 (Unexpected pedal
action) ........................................................................\
67 Diagnostic Procedure 9 (Long stopping distance) ....67
Diagnostic Procedure 10 (ABS does not work.) .......68
Diagnostic Procedure 11 (Pedal vibration and
noise) ........................................................................\
.68
Diagnostic Procedure 12 (Warning lamp does
not come on when ignition switch is turned ON.) .....69
Diagnostic Procedure 13 (Warning lamp stays on
when ignition switch is turned ON.)...........................71
SERVICE DATA AND SPECIFICATIONS (SDS) ..........72
General Speci®cations ...............................................72
Inspection and Adjustment ........................................73
When you read wiring diagrams:
+ Read GI section, ``HOW TO READ WIRING DIAGRAMS''.
+ See EL section, ``POWER SUPPLY ROUTING'' for power distribution circuit.
When you perform trouble diagnoses, read GI section, ``HOW TO FOLLOW FLOW CHART
IN TROUBLE DIAGNOSES'' and ``HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN
ELECTRICAL INCIDENT''.

Supplemental Restraint System (SRS) ``AIR
BAG'' and ``SEAT BELT PRE-TENSIONER''
The Supplemental Restraint System such as ``AIR BAG'' and ``SEAT BELT PRE-TENSIONER'' used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger in a frontal collision.
The SRS system composition which is available to NISSAN MODEL Y61 is as follows (The composition var-
ies according to the destination.):
Driver air bag module (located in the center of the steering wheel), front passenger air bag module (located
on the instrument panel on passenger side), seat belt pre-tensioner, a diagnosis sensor unit, warning lamp,
wiring harness and spiral cable.
Information necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
+ To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag in¯ation, all maintenance must be performed
by an authorized NISSAN dealer.
+ Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the RS section.
+ Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. Spiral Cable and wiring harnesses covered with yellow insulation either just before
the harness connectors or for the complete harness are related to the SRS.
Precautions for Brake System
+Use brake ¯uid ``DOT 3''.
+ Never reuse drained brake ¯uid.
+ 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.
+ To clean master cylinder parts, disc brake caliper parts or
wheel cylinder parts, use clean brake ¯uid.
+ Never use mineral oils such as gasoline or kerosene. They
will ruin rubber parts of hydraulic system.
+ Use ¯are nut wrench when removing and installing brake
tubes.
+ Always torque brake lines when installing.
WARNING:
Clean brakes with a vacuum dust collector to minimize risk of
health hazard from powder caused by friction.
Commercial Service Tools
Tool name Description
j
1Flare nut crowfoot
j
2Torque wrench
NT360
Removing and installing each brake piping
a: 10 mm (0.39 in)
Brake ¯uid pressure gauge
NT151
Measuring brake ¯uid pressure
SBR686C
PRECAUTIONS AND PREPARATION
BR-1

NVH Troubleshooting Chart
Use the chart below to help you ®nd the cause of the symptom. If necessary, repair or replace these parts.
Reference page
BR-20, 24, 31BR-31Ð
Ð
Ð
BR-23, 27, 31
BR-23, 27, 31 Ð
Ð
Ð
BR-23, 27 BR-31
NHV in PD section
NHV in PD section
NHV in FA, RA section
NHV in FA section
NHV in FA section
NHV in FA section
NHV in ST section
Possible cause and
SUSPECTED PARTS
Linings or pads - damaged
Linings or pads - uneven wear
Return spring damaged
Shims damaged
Rotor or drum imbalance
Rotor or drum damage
Rotor or drum runout
Rotor or drum deformation
Rotor or drum de¯ection
Rotor or drum rust
Rotor thickness variation
Drum out of round
PROPELLER SHAFT
DIFFERENTIAL
AXLE AND SUSPENSION
TIRES
ROAD WHEEL
AXLE SHAFT
STEERING
Symptom BRAKE Noise
XXXX XXXXXXX
Shake X X X X X X X
Shimmy, Judder X X XXXXXX XXX X
X: Applicable
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
BR-2

1. Ensure vehicle is unladen condition*.* Fuel, radiator coolant and engine oil full. Spare tire, jack,hand tools and mats in designated positions.
2. Have a driver sit in the driver's seat and one person sit on the rear end. Then have the person on the rear end slowly get off
the vehicle. This is necessary to stabilize suspension de¯ec-
tion.
3. Gradually depress brake pedal and attach a lever to the stop- per bolt, then adjust length ``L'' as follows:Length ``L'': Approx. 175.2 - 178.2 mm (6.90 - 7.02 in)
4. Remove front LH tire.
5. Connect tool to air bleeders on front LH brake caliper and rear LH or RH brake wheel cylinder.
6. Install front LH tire.
Before installing front LH tire, con®rm the tool is not touching
the front LH wheel.
7. Bleed air from Tool.
8. Raise front brake pressure to 4,904 kPa (49.0 bar, 50 kg/cm
2,
711 psi) and 9,807 kPa (98.1 bar, 100 kg/cm2, 1,422 psi) and
check rear brake pressure. Rear brake pressure: Refer to table on next page.
SBR287E
SBR822BA
SBR823BA
SBR377D
BRAKE HYDRAULIC LINE/CONTROL VALVE
Load Sensing Valve (Cont'd)
BR-7

1. Loosen lock nut and adjust pedal free height by turning brakebooster input rod. Then tighten lock nut.
Make sure that tip of input rod stays inside.
2. Adjust clearance ``C
1'' and ``C2'' with stop lamp switch and
ASCD switch respectively. Then tighten lock nuts.
3. Check pedal free play.
Make sure that stop lamp is off when pedal is released.
4. Check brake pedal's depressed height while engine is running. If depressed height is below speci®ed value, check brake sys-
tem for leaks, accumulation of air or any damage to compo-
nents (master cylinder, wheel cylinder, etc.). Then make nec-
essary repairs.
SBR824B
BRAKE PEDAL AND BRACKET
Adjustment (Cont'd)
BR-11

Inspection Ð Rotor
RUNOUT
1. Secure rotor to wheel hub with at least two nuts (M12 ý 1.25).
2. Check runout using a dial indicator.
Make sure that wheel bearing axial end play is within the
speci®cations before measuring. Refer to FA section (``Front
Wheel Bearing'', ``ON-VEHICLE SERVICE'').Maximum runout:0.1 mm (0.004 in)
3. If the runout is out of speci®cation, ®nd minimum runout posi- tion as follows:
a. Remove nuts and rotor from wheel hub.
b. Shift the rotor one hole and secure rotor to wheel hub withnuts.
c. Measure runout.
d. Repeat steps a. to c. so that minimum runout position can be found.
4. If the runout is still out of speci®cation, turn rotor with on-car brake lathe (``MAD, DL-8700'', ``AMMCO 700 and 705'' or
equivalent).
THICKNESS
Thickness variation (At least 8 positions): Maximum 0.015 mm (0.0006 in)
If thickness variation exceeds the speci®cation, turn rotor with on-
car brake lathe. Rotor repair limit:30.0 mm (1.181 in)
Assembly
1. Insert piston seal into groove on cylinder body.
2. With piston boot ®tted to piston, insert piston boot into grooveon cylinder body and install piston.
3. Properly secure piston boot
CAUTION:
Secure dust seal properly.
Installation
CAUTION:
+ Re®ll with new brake ¯uid ``DOT 3''.
+ Never reuse drained brake ¯uid.
1. Install caliper assembly.
2. Install brake hose to caliper securely.
3. Install all parts and secure all bolts.
4. Bleed air. Refer to ``Bleeding Brake System'', BR-4.
SBR019B
SBR020B
SBR574
SBR175E
FRONT DISC BRAKE
BR-24

Inspection Ð Rotor
RUNOUT
1. Secure rotor to wheel hub with at least two nuts (M12 ý 1.25).
2. Check runout using a dial indicator.
Make sure that wheel bearing axial end play is within the
speci®cations before measuring. Refer to ``Rear Wheel Bear-
ing'' in RA section.Maximum runout:0.1 mm (0.004 in)
3. If the runout is out of speci®cation, ®nd minimum runout posi- tion as follows:
a. Remove nuts and rotor from wheel hub.
b. Shift the rotor one hole and secure rotor to wheel hub withnuts.
c. Measure runout.
d. Repeat steps a. to c. so that minimum runout position can be found.
4. If the runout is still out of speci®cation, turn rotor with on-car brake lathe (``MAD, DL-8700'', ``AMMCO 700 and 705'' or
equivalent).
THICKNESS
Thickness variation (At least 8 positions): Maximum 0.015 mm (0.0006 in)
If thickness variation exceeds the speci®cation, turn rotor with on-
car brake lathe. Rotor repair limit:16.0 mm (0.630 in)
Assembly
1. Insert piston seal into groove on cylinder body.
2. With piston boot ®tted to piston, insert piston boot into grooveon cylinder body and install piston.
3. Properly secure piston boot
Installation
CAUTION:
+ Re®ll with new brake ¯uid ``DOT 3''.
+ Never reuse drained brake ¯uid.
1. Install caliper assembly.
2. Install brake hose to caliper securely.
3. Install all parts and secure all bolts.
4. Bleed air. Refer to ``Bleeding Brake System'', BR-4.
SBR389A
SBR390A
SBR574
SBR184E
REAR DISC BRAKE
BR-28

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