brake INFINITI QX4 2001 Factory Owners Manual

SBR093A
b. Tighten the two bolts gradually.
SBR266CA
2. After removing shoe hold pin by rotating push retainer, remove
leading shoe then remove trailing shoe. Remove spring by
rotating shoes in direction arrow.
Be careful not to damage wheel cylinder piston boots.
3. Remove adjuster.
SBR267CA
4. Disconnect parking brake cable from toggle lever.
Be careful not to damage parking brake cable when separat-
ing it.
SBR093B
5. Remove retainer ring with a suitable tool. Then separate toggle
lever and brake shoe.
SBR816B
InspectionNBBR0040WHEEL CYLINDERNBBR0040S01ICheck wheel cylinder for leakage.
ICheck for wear, damage and loose conditions.
Replace if any such condition exists.
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REAR DRUM BRAKE
Removal (Cont'd)
BR-27

SBR215B
Wheel Cylinder OverhaulNBBR0041ICheck all internal parts for wear, rust and damage. Replace if
necessary.
IPay attention so as not to scratch cylinder when installing pis-
tons.
SBR095A
InspectionNBBR0042DRUMNBBR0042S01Maximum inner diameter: 296.5 mm (11.67 in)
Out-of-roundness: 0.03 mm (0.0012 in) or less
IContact surface should be fine finished with No. 120 to 150
emery paper.
IUsing a drum lathe, lathe brake drum if it shows scoring, par-
tial wear or stepped wear.
IAfter brake drum has been completely reconditioned or
replaced, check drum and shoes for proper contact pattern.
SBR021A
LININGNBBR0042S02Check lining thickness.
Standard lining thickness:
6.1 mm (0.240 in)
Lining wear limit (A):
1.5 mm (0.059 in)
SBR092B
InstallationNBBR0043Always perform shoe clearance adjustment. Refer to BR-31.
1. Fit toggle lever to brake shoe (trailing side) with retainer ring.
ABR371
2. Apply brake grease to the contact areas (indicated by arrows
and hatching) shown at left.
REAR DRUM BRAKE
Wheel Cylinder Overhaul
BR-28

SBR217B
3. Shorten adjuster by rotating it.
IPay attention to direction of adjuster.
Wheel Screw Depression
Left Left-hand thread Yes
Right Right-hand thread No
SBR279B
4. Connect parking brake cable to toggle lever.
5. Install all parts.
Be careful not to damage wheel cylinder piston boots.
6. Check all parts are installed properly.
Pay attention to direction of adjuster assembly.
7. Install brake drum.
8. When installing new wheel cylinder or overhauling wheel
cylinder, bleed air. Refer to ªBleeding Brake Systemº, BR-8.
9. Adjust parking brake. Refer to ªAdjustmentº, ªPARKING
BRAKE CONTROLº, BR-31.
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REAR DRUM BRAKE
Installation (Cont'd)
BR-29

ComponentsNBBR0044
SBR667E
SBR390D
Removal and InstallationNBBR00451. To remove parking brake cable, first remove center console.
2. Disconnect warning lamp connector.
3. Remove bolts, slacken off and remove adjusting nut.
SBR391D
4. Disconnect cable. Refer to ªRemovalº, ªREAR DRUM BRAKEº,
BR-26.
InspectionNBBR00461. Check control lever for wear or other damage. Replace if nec-
essary.
2. Check wires for discontinuity or deterioration. Replace if nec-
essary.
3. Check warning lamp and switch. Replace if necessary.
4. Check parts at each connecting portion and, if deformed or
damaged, replace.
PARKING BRAKE CONTROL
Components
BR-30

SBR042D
AdjustmentNBBR00471. Adjust clearance between shoe and drum as follows:
a. Release parking brake lever and loosen adjusting nut.
b. Depress brake pedal fully at least 10 times with engine run-
ning.
2. Pull control lever4-5notches. Then adjust control lever by
turning adjusting nut.
SBR073D
3. Pull control lever with specified amount of force. Check lever
stroke and ensure smooth operation.
Number of notches:6-8
4. Bend warning lamp switchplate to ensure:
IWarning lamp comes on when lever is lifted ªAº notches.
IWarning lamp goes out when lever is fully released.
Number of ªAº notches: 1 or less
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PARKING BRAKE CONTROL
Adjustment
BR-31

PurposeNBBR0087The 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.
1) Improves proper tracking performance through steering wheel operation.
2) Eases obstacle avoidance through steering wheel operation.
3) Improves vehicle stability.
OperationNBBR0088IWhen the vehicle speed is less than 10 km/h (6 MPH) this system does not work.
IThe 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 ªONº. After the engine is started, the ABS warning lamp
turns off. The system performs a test the first time the vehicle reaches 6 km/h (4 MPH). A mechanical noise
may be heard as the ABS performs this self-test. This is a normal part of the self-test feature. If a mal-
function is found during this check, the ABS warning lamp will stay on.
IWhile driving, a mechanical noise may be heard during ABS operation. This is a normal condition.
ABS Hydraulic CircuitNBBR0089
SBR859D
1. Inlet solenoid valve
2. Outlet solenoid valve
3. Reservoir4. Pump
5. Motor
6. Inlet valve7. Outlet valve
8. Bypass check valve
9. Damper
DESCRIPTIONABS
Purpose
BR-32

System ComponentsNBBR0090
SBR447EB
SBR124B
System DescriptionNBBR0091SENSORNBBR0091S01The 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 front sensors are installed on the front spindles
and the rear sensors are installed on the rear spindles. As the
wheel rotates, the sensor generates a sine-wave pattern. The fre-
quency and voltage increase(s) as the rotating speed increases.
SBR668E
CONTROL UNIT (BUILT-IN ABS ACTUATOR AND
ELECTRIC UNIT)
NBBR0091S02The 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-33.)
SBR482E
ABS ACTUATOR AND ELECTRIC UNITNBBR0091S03The ABS actuator and electric unit contains:
IAn electric motor and pump
ITwo relays
ISix solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
IABS control unit
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DESCRIPTIONABS
System Components
BR-33

This component controls the hydraulic circuit and increases, holds
or decreases hydraulic pressure to all or individual wheels. The
ABS actuator and electric unit is serviced as an assembly.
ABS Actuator OperationNBBR0091S0301
Inlet solenoid
valveOutlet solenoid
valve
Normal brake operation OFF (Open) OFF (Closed)Master cylinder brake fluid pressure is directly
transmitted to caliper via the inlet solenoid valve.
ABS operationPressure hold ON (Closed) OFF (Closed)Hydraulic circuit is shut off to hold the caliper
brake fluid pressure.
Pressure
decreaseON (Closed) ON (Open)Caliper brake fluid is sent to reservoir via the out-
let solenoid valve. Then it is pushed up to the
master cylinder by pump.
Pressure increase OFF (Open) OFF (Closed)Master cylinder brake fluid pressure is transmitted
to caliper.
G SENSOR (4WD MODELS ONLY)NBBR0091S05The 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 control unit.
SBR456E
The reed switch turns on when it is affected by a magnetic field.
During sudden deceleration (braking on a high  road), the weight
moves and the magnet in the weight moves away from the reed
switch. The magnetic field then diminishes and the reed switch
turns off.
DESCRIPTIONABS
System Description (Cont'd)
BR-34

Self-diagnosisNBBR0095FUNCTIONNBBR0095S01IWhen a problem occurs in the ABS, the warning lamp on the
instrument panel comes on. To start the self-diagnostic results
mode, ground the self-diagnostic (check) terminal located on
data link connector. The location of the malfunction is indicated
by the warning lamp flashing.
SELF-DIAGNOSIS PROCEDURENBBR0095S021. Drive vehicle over 30 km/h (19 MPH) for at least one minute.
2. Turn ignition switch OFF.
SBR665E
3. Ground terminal 9 of data link connector with a suitable har-
ness.
4. Turn ignition switch ON while grounding terminal 9.
Do not depress brake pedal.
SBR668E
5. After 3.0 seconds, the warning lamp starts flashing to indicate
the malfunction code No. (See NOTE.)
6. Verify the location of the malfunction with the malfunction code
chart. Refer to BR-54. Then make the necessary repairs fol-
lowing the diagnostic procedures.
7. After the malfunctions are repaired, erase the malfunction
codes stored in the control unit. Refer to BR-42.
8. Rerun the self-diagnostic results mode to verify that the mal-
function codes have been erased.
9. Disconnect the check terminal from the ground. The self-diag-
nostic results mode is now complete.
10. Check warning lamp for deactivation after driving vehicle over
30 km/h (19 MPH) for at least one minute.
11. After making certain that warning lamp does not come on, test
the ABS in a safe area to verify that it functions properly.
NOTE:
The indication terminates after 5 minutes.
However, when the ignition switch is turned from OFF to ON, the
indication starts flashing again.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONABS
Self-diagnosis
BR-41

DATA MONITOR MODENBBR0097S05
MONITOR ITEM CONDITION SPECIFICATION
FR RH SENSOR
FR LH SENSOR
RR RH SENSOR
RR LH SENSORDrive vehicle.
(Each wheel is rotating.)Wheel speed signal
(Almost the same speed as speedometer.)
STOP LAMP SW Brake is depressed.Depress the pedal: ON
Release the pedal: OFF
G-SWITCHHVehicle is driven.
Vehicle is stopped.
Brake is applied.During sudden braking while driving on high  roads (asphalt
roads, etc.): OFF
While vehicle is stopped or during constant-speed driving: ON
FR RH IN SOL
FR RH OUT SOL
FR LH IN SOL
FR LH OUT SOL
RR IN SOL
RR OUT SOL1. Drive vehicle at speeds
over 30 km/h (19 MPH) for at
least 1 minute.
2. Engine is running.Operating conditions for each solenoid valve are indicated. ABS
is not operating: OFF
MOTOR RELAYABS is not operating: OFF
ABS is operating: ON
ACTUATOR RELAY
Ignition switch is ON or
engine is running.Ignition switch ON (Engine stops): OFF
Engine running: ON
WARNING LAMPABS warning lamp is turned on: ON
ABS warning lamp is turned off: OFF
BATTERY VOLT Power supply voltage for control unit
ABS OPER SIGABS is not operating: OFF
ABS is operating: ON
H: 4WD model only
ACTIVE TEST MODENBBR0097S06
TEST ITEM CONDITION JUDGEMENT
FR RH SOLENOID
FR LH SOLENOID
RR SOLENOID
Engine is running.Brake fluid pressure control operation
IN SOL OUT SOL
UP (Increase): OFF OFF
KEEP (Hold): ON OFF
DOWN (Decrease): ON ON
ABS MOTORABS actuator motor
ON: Motor runs (ABS motor relay ON)
OFF: Motor stops (ABS motor relay OFF)
ABS OPER SIGIgnition switch is ON or
engine is running.ON: Set ABS OPER SIG ªONº (ABS is operating.)
OFF: Set ABS OPER SIG ªOFFº (ABS is not operating.)
G SWITCHHIgnition switch is ON.G SWITCH (G SENSOR)
ON: Set G SWITCH MONITOR ªONº (G switch circuit is
closed.)
OFF: Set G SWITCH MONITOR ªOFFº (G switch circuit is
open.)
H: 4WD models only
NOTE:
Active test will automatically stop ten seconds after the test starts. (TEST IS STOPPED monitor shows ON.)
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONABS
CONSULT-II Inspection Procedure (Cont'd)
BR-48