1998 NISSAN PATROL Brake System Workshop Manual

BRAKE SYSTEM
SECTION
BR
CONTENTS
PRECAUTIONS AND PREPARATION ............................1
Supplemental Restraint System (SRS) ``AIR
BAG'' and ``SEAT BELT PRE-TENSIONER''...............1
Precautions for Brake System .....................................1
Commercial Service Tools ...........................................1
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING .....................................................2
NVH Troubleshooting Chart.........................................2
CHECK AND ADJUSTMENT ..........................................3
Checking Brake Fluid Level.........................................3
Checking Brake Line ...................................................3
Changing Brake Fluid ..................................................3
Bleeding Brake System ...............................................4
BRAKE HYDRAULIC LINE/CONTROL VALVE ..............5
Brake Hydraulic Line ...................................................5
Load Sensing Valve .....................................................6
BRAKE PEDAL AND BRACKET ..................................10
Removal and Installation ...........................................10
Inspection...................................................................10
Adjustment .................................................................10
MASTER CYLINDER .....................................................12
Removal .....................................................................12
Disassembly...............................................................13
Inspection...................................................................13
Assembly ...................................................................13
Installation ..................................................................14
BRAKE BOOSTER ........................................................15
Brake Booster ............................................................15
VACUUM PIPING (LHD models) ..................................17
Vacuum Hose ............................................................17
VACUUM PIPING (RHD models) .................................18
Vacuum Hose ............................................................18
VACUUM PIPING ...........................................................19
VACUUM PUMP ............................................................20
Removal and Installation ...........................................20
FRONT DISC BRAKE ...................................................21
Pad Replacement ......................................................21
Removal .....................................................................23
Disassembly...............................................................23 Inspection Ð Caliper .................................................23
Inspection Ð Rotor ....................................................24
Assembly ...................................................................24
Installation ..................................................................24
REAR DISC BRAKE ......................................................25
Pad Replacement ......................................................25
Removal .....................................................................27
Disassembly...............................................................27
Inspection Ð Caliper .................................................27
Inspection Ð Rotor ....................................................28
Assembly ...................................................................28
Installation ..................................................................28
PARKING CENTER BRAKE CONTROL ......................29
Removal .....................................................................29
Inspection...................................................................29
Installation ..................................................................30
Adjustment .................................................................30
PARKING CENTER BRAKE .........................................31
Removal and Installation ...........................................31
Inspection Ð Drum ....................................................32
Inspection Ð Lining ...................................................32
ANTI-LOCK BRAKE SYSTEM ......................................33
Purpose......................................................................33
Operation ...................................................................33
ABS Hydraulic Circuit ................................................33
System Components .................................................34
System Description ....................................................34
Removal and Installation ...........................................36
TROUBLE DIAGNOSES ...............................................39
How to Perform Trouble Diagnoses for Quick
and Accurate Repair ..................................................39
Preliminary Check......................................................40
Component Parts and Harness Connector
Location .....................................................................41
Circuit Diagram for Quick Pinpoint Check.................42
Wiring Diagram Ð ABS Ð ........................................43
Self-diagnosis ............................................................47
CONSULT ..................................................................50
CONSULT Inspection Procedure...............................51
BR

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

Checking Brake Fluid Level
+Check ¯uid level in reservoir tank. It should be between Max
and Min lines on reservoir tank.
+ If ¯uid level is extremely low, check brake system for leaks.
+ If the brake warning lamp comes on, check brake ¯uid level
switch and parking brake switch.
Checking Brake Line
CAUTION:
If leakage occurs around joints, retighten or, if necessary,
replace damaged parts.
1. Check brake lines (tubes and hoses) for cracks, deterioration
or other damage. Replace any damaged parts.
2. Check for oil leakage by fully depressing brake pedal while engine is running.
Changing Brake Fluid
CAUTION:
+Re®ll with new brake ¯uid ``DOT 3''.
+ Always keep ¯uid level higher than minimum line on res-
ervoir tank.
+ 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.
1. Clean inside of reservoir tank, and re®ll with new brake ¯uid.
2. Connect a vinyl tube to each air bleeder valve.
3. Drain brake ¯uid from each air bleeder valve by depressing brake pedal.
4. Re®ll until brake ¯uid comes out of each air bleeder valve. Use same procedure as in bleeding hydraulic system to re®ll
brake ¯uid. Refer to ``Bleeding Brake System'', BR-4.
SBR451D
SBR389C
SBR419C
CHECK AND ADJUSTMENT
BR-3

Bleeding Brake System
CAUTION:
+Carefully monitor brake ¯uid level at master cylinder dur-
ing bleeding operation.
+ If master cylinder is suspected to have air inside, bleed air
from master cylinder ®rst. Refer to ``Installation'', ``MAS-
TER CYLINDER'', BR-14.
+ Fill reservoir with new brake ¯uid ``DOT 3''. Make sure it is
full at all times while bleeding air out of system.
+ Place a container under master cylinder to avoid spillage
of brake ¯uid.
+ For models with ABS, turn ignition switch OFF and discon-
nect ABS actuator connectors or battery ground cable.
+ Bleed air in the following order.
1. LSV air bleeder
2. Left rear brake
3. Right rear brake
4. Left front brake
5. Right front brake
1. Connect a transparent vinyl tube to air bleeder valve.
2. Fully depress brake pedal several times.
3. With brake pedal depressed, open air bleeder valve to release air.
4. Close air bleeder valve.
5. Release brake pedal slowly.
6. Repeat steps 2. through 5. until clear brake ¯uid comes out of air bleeder valve.
7. Tighten air bleeder valve.
:7-9N zm (0.7 - 0.9 kg-m, 61 - 78 in-lb)
SBR995
SBR419C
CHECK AND ADJUSTMENT
BR-4

Brake Hydraulic Line
YBR146
SBR161E
BRAKE HYDRAULIC LINE/CONTROL VALVE
BR-5

REMOVAL
CAUTION:
+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.
+ All hoses must be free from excessive bending, twisting
and pulling.
1. Connect vinyl tube to air bleeder valve.
2. Drain brake ¯uid from each air bleeder valve by depressing brake pedal.
3. Remove ¯are nut connecting brake tube and hose, then with- draw lock spring.
4. Cover openings to prevent entrance of dirt whenever discon- necting brake line.
INSPECTION
Check brake lines (tubes and hoses) for cracks, deterioration or
other damage. Replace any damaged parts.
INSTALLATION
CAUTION:
+Re®ll with new brake ¯uid ``DOT 3''.
+ Never reuse drained brake ¯uid.
1. Tighten all ¯are nuts and connecting bolts. Flare nut:
:15-17N zm (1.5 - 1.7 kg-m, 11 - 12 ft-lb)
Connecting bolt:
:17-19N zm (1.7 - 1.9 kg-m, 12 - 14 ft-lb)
2. Re®ll until new brake ¯uid comes out of each air bleeder valve.
3. Bleed air. Refer to ``Bleeding Brake System'', BR-4.
Load Sensing Valve
INSPECTION
CAUTION:
+ Carefully monitor brake ¯uid level at master cylinder.
+ Use 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 paint
areas, wash it away with water immediately.
+ Depress pedal slowly when raising front brake pressure.
+ Check rear brake pressure 2 seconds after front brake
pressure reaches speci®ed value.
+ For models with ABS disconnect harness connectors from
ABS actuator relay before checking.
SBR992
SBR686C
BRAKE HYDRAULIC LINE/CONTROL VALVE
Brake Hydraulic Line (Cont'd)
BR-6