2001 INFINITI QX4 Bleed

BRAKE SYSTEM
SECTION
BR
CONTENTS
PRECAUTIONS...............................................................3
Supplemental Restraint System (SRS)²AIR
BAG²and²SEAT BELT PRE-TENSIONER²...............3
Precautions for Brake System .....................................3
Wiring Diagrams and Trouble Diagnoses....................4
PREPARATION...............................................................5
Special Service Tools ..................................................5
Commercial Service Tools ...........................................5
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING.....................................................6
NVH Troubleshooting Chart.........................................6
ON-VEHICLE SERVICE..................................................7
Checking Brake Fluid Level.........................................7
Checking Brake Line ...................................................7
Changing Brake Fluid ..................................................7
Bleeding Brake System ...............................................8
BRAKE HYDRAULIC LINE.............................................9
Hydraulic Circuit...........................................................9
Removal .....................................................................10
Inspection...................................................................10
Installation ..................................................................10
PROPORTIONING VALVE (2WD)................................ 11
Inspection................................................................... 11
Removal and Installation (Built-in type)..................... 11
LOAD SENSING VALVE (4WD)...................................12
Inspection...................................................................12
Removal and Installation ...........................................12
BRAKE PEDAL AND BRACKET..................................14
Removal and Installation ...........................................14
Inspection...................................................................14
Adjustment .................................................................14
MASTER CYLINDER.....................................................16
Removal .....................................................................16
Disassembly...............................................................16
Inspection...................................................................17
Assembly ...................................................................17
Installation ..................................................................18
BRAKE BOOSTER........................................................19
On-vehicle Service.....................................................19OPERATING CHECK...............................................19
AIRTIGHT CHECK...................................................19
Removal .....................................................................19
Inspection...................................................................19
OUTPUT ROD LENGTH CHECK..............................19
Installation ..................................................................20
VACUUM PIPING...........................................................21
Vacuum Hose ............................................................21
Removal and Installation ...........................................21
Inspection...................................................................21
HOSES AND CONNECTORS...................................21
CHECK VALVE........................................................21
FRONT DISC BRAKE...................................................22
Components...............................................................22
Pad Replacement ......................................................22
Removal .....................................................................23
Disassembly...............................................................24
Inspection...................................................................24
CALIPER.................................................................24
ROTOR...................................................................24
Assembly ...................................................................25
Installation ..................................................................25
Brake Burnishing Procedure......................................25
REAR DRUM BRAKE...................................................26
Components...............................................................26
Removal .....................................................................26
Inspection...................................................................27
WHEEL CYLINDER..................................................27
Wheel Cylinder Overhaul...........................................28
Inspection...................................................................28
DRUM.....................................................................28
LINING....................................................................28
Installation ..................................................................28
PARKING BRAKE CONTROL......................................30
Components...............................................................30
Removal and Installation ...........................................30
Inspection...................................................................30
Adjustment .................................................................31
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
ST
RS
BT
HA
SC
EL
IDX

SBR451D
Checking Brake Fluid LevelNBBR0006ICheck fluid level in reservoir tank. It should be between Max
and Min lines on reservoir tank.
IIf fluid level is extremely low, check brake system.
IIf the brake warning lamp comes on, check brake fluid level
switch and parking brake switch.
SBR389C
Checking Brake LineNBBR0007CAUTION:
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.
SBR419C
Changing Brake FluidNBBR0008CAUTION:
IRefill with new brake fluid ªDOT 3º.
IAlways keep fluid level higher than minimum line on res-
ervoir tank.
INever reuse drained brake fluid.
IBe careful not to splash brake fluid on painted areas; it
may cause paint damage. If brake fluid is splashed on
painted areas, wash it away with water immediately.
1. Clean inside of reservoir tank, and refill with new brake fluid.
2. Connect a vinyl tube to each air bleeder valve.
3. Drain brake fluid from each air bleeder valve by depressing
brake pedal.
4. Refill until brake fluid comes out of each air bleeder valve.
Use same procedure as in bleeding hydraulic system to refill
brake fluid.
Refer to ªBleeding Brake Systemº, BR-8.
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
ST
RS
BT
HA
SC
EL
IDX
ON-VEHICLE SERVICE
Checking Brake Fluid Level
BR-7

SBR995
Bleeding Brake System=NBBR0009CAUTION:
ICarefully monitor brake fluid level at master cylinder dur-
ing bleeding operation.
IIf master cylinder is suspected to have air inside, bleed air
from master cylinder first. Refer to ªInstallationº, ªMAS-
TER CYLINDERº, BR-18.
IFill reservoir with new brake fluid ªDOT 3º. Make sure it is
full at all times while bleeding air out of system.
IPlace a container under master cylinder to avoid spillage
of brake fluid.
ITurn ignition switch OFF and disconnect ABS actuator
and electric unit connectors or battery ground cable.
IBleed air in the following order.
1. LSV air bleeder (4WD)
2. Left rear brake
3. Right rear brake
4. Left front brake
5. Right front brake
SBR419C
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 fluid comes out of
air bleeder valve.
7. Tighten air bleeder valve.
:7-9N´m(0.7 - 0.9 kg-m, 61 - 78 in-lb)
ON-VEHICLE SERVICE
Bleeding Brake System
BR-8

SBR992
RemovalNBBR0011CAUTION:
IBe careful not to splash brake fluid on painted areas; it
may cause paint damage. If brake fluid is splashed on
painted areas, wash it away with water immediately.
IAll hoses must be free from excessive bending, twisting
and pulling.
1. Connect vinyl tube to air bleeder valve.
2. Drain brake fluid from each air bleeder valve by depressing
brake pedal.
3. Remove flare nut connecting brake tube and hose, then with-
draw lock spring.
4. Cover openings to prevent entrance of dirt whenever discon-
necting brake line.
InspectionNBBR0012Check brake lines (tubes and hoses) for cracks, deterioration or
other damage. Replace any damaged parts.
SBR686C
InstallationNBBR0013CAUTION:
IRefill with new brake fluid ªDOT 3º.
INever reuse drained brake fluid.
1. Tighten all flare nuts and connecting bolts.
Flare nut:
: 15 - 17 N´m (1.5 - 1.8 kg-m, 11 - 13 ft-lb)
Connecting bolt:
: 17 - 19 N´m (1.7 - 2.0 kg-m, 12 - 14 ft-lb)
2. Refill until new brake fluid comes out of each air bleeder valve.
3. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
BRAKE HYDRAULIC LINE
Removal
BR-10

SBR822BA
InspectionNBBR0116
SBR823BA
SBR705AA
CAUTION:
ICarefully monitor brake fluid level at master cylinder.
IUse new brake fluid ªDOT 3º.
IBe careful not to splash brake fluid on painted areas; it
may cause paint damage. If brake fluid is splashed on
paint areas, wash it away with water immediately.
IDepress pedal slowly when raising front brake pressure.
ICheck rear brake pressure 2 seconds after front brake
pressure reaches specified value.
IDisconnect harness connectors from ABS actuator and
electric unit before checking.
1. Remove front LH tire.
2. Connect tool to air bleeders on front LH brake caliper and rear
LH or RH brake wheel cylinder.
3. Install front LH tire.
Before installing front LH tire, confirm the tool is not touching
the front LH wheel.
4. Bleed air from the tool.
5. Check fluid pressure by depressing brake pedal.
kPa (kg/cm2, psi)
Applied pressure (Front brake) D16,375 (65, 924)
Output pressure (Rear brake) D
23,432 - 3,825
(35 - 39, 498 - 555)
If output pressure is out of specifications, replace master cylinder
assembly (built-in type).
6. Bleed air after disconnecting the tool. Refer to ªBleeding Brake
Systemº, BR-8.
7. Install front LH tire.
Removal and Installation (Built-in type)NBBR0117Always replace together with master cylinder as an assembly.
IRefer to ªMASTER CYLINDERº, BR-16.
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
ST
RS
BT
HA
SC
EL
IDX
PROPORTIONING VALVE (2WD)
Inspection
BR-11

SBR379DC
1. Tighten all flare nuts and mounting bolts.
Flare nut:
: 15 - 17 N´m (1.5 - 1.8 kg-m, 11 - 13 ft-lb)
2. Refill until new brake fluid comes out of each air bleeder valve.
3. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
ST
RS
BT
HA
SC
EL
IDX
LOAD SENSING VALVE (4WD)
Removal and Installation (Cont'd)
BR-13

RemovalNBBR0019CAUTION:
IBe careful not to splash brake fluid on painted areas; it
may cause paint damage. If brake fluid is splashed on
painted areas, wash it away with water immediately.
IIn the case of brake fluid leakage from the master cylinder,
disassemble the cylinder. Then check piston cups for
deformation or scratches and replace necessary parts.
1. Connect a vinyl tube to air bleeder valve.
2. Drain brake fluid from each air bleeder valve, depressing brake
pedal to empty fluid from master cylinder.
3. Remove brake pipe flare nuts.
4. Remove master cylinder mounting nuts.
SBR879D
SBR938A
DisassemblyNBBR00201. Bend claws of stopper cap outward.
MASTER CYLINDER
Removal
BR-16

ABR190
InstallationNBBR0023CAUTION:
IRefill with new brake fluid ªDOT 3º.
INever reuse drained brake fluid.
1. Place master cylinder onto brake booster and secure mount-
ing nuts lightly.
2. Torque mounting nuts.
: 12 - 15 N´m (1.2 - 1.5 kg-m,9-11ft-lb)
3. Fill up reservoir tank with new brake fluid.
4. Plug all ports on master cylinder with fingers to prevent air
suction while releasing brake pedal.
5. Have driver depress brake pedal slowly several times until no
air comes out of master cylinder.
6. Fit brake lines to master cylinder.
7. Tighten flare nuts.
: 15 - 17 N´m (1.5 - 1.8 kg-m, 11 - 13 ft-lb)
8. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
MASTER CYLINDER
Installation
BR-18