2004 INFINITI QX56 torque

FRONT DISC BRAKE
BR-25
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Revision: August 20072004 QX56
2. Apply brake fluid to piston and piston boot, then install piston
boot in to piston groove.
CAUTION:
Do not reuse piston boot.
3. Insert into cylinder body by hand and insert piston boot piston-side lip into piston groove.
CAUTION:
Press piston evenly and vary the pressing point to prevent cylinder body inner wall from being
rubbed.
4. Install sliding pins and sliding pin boots to torque member.
CAUTION:
Trailing/upper sliding pin must be replaced at each service.
5. Install cylinder body. Tighten sliding pin bolt to the specified torque. Refer to BR-21, "
Components" .
DISC ROTOR INSPECTION
Visual Inspection
Check surface of disc rotor for uneven wear, cracks, and serious damage. If any of them is detected, replace
applicable part.
Runout Inspection
1. Using wheel nuts, fix disc rotor to wheel hub at 2 or more positions.
2. Inspect runout using a dial gauge. (Measured at 10 mm (0.39 in)
inside the disc edge.)
NOTE:
Make sure that wheel bearing axial end play is within the specifi-
cations before measuring runout. Refer to FA X -5 , "
WHEEL
BEARING INSPECTION" .
3. If runout is outside the limit, find the minimum runout point by
shifting mounting positions of disc rotor and wheel hub by one
hole.
4. If runout still out of specification, turn rotor with on-car brake
lathe.
Thickness Inspection
Using a micrometer, check thickness of disc rotor. If thickness is
either at or below the wear limit, or exceeds maximum uneven wear,
replace disc rotor.
BRAKE BURNISHING PROCEDURE
Burnish brake contact surface according to the following procedure after refinishing or replacing rotors, after
replacing pads, or if a soft pedal occurs at very low mileage.
WFIA0211E
Runout limit (on vehicle) : 0.04 mm (0.0016 in)
BRA0013D
Standard thickness : 26.0 mm (1.024 in)
Repair limit thickness : 24.5 mm (0.965 in)
Maximum uneven wear
(Measured at 8 positions): 0.015 mm (0.0006 in)
SBR0 20 B

BR-28
REAR DISC BRAKE
Revision: August 20072004 QX56
CAUTION:

While removing cylinder body, never depress brake pedal because piston will pop out.

It is not necessary to remove bolts on torque member and brake hose except for disassembly or
replacement of cylinder body assembly. In this case, hang cylinder body with a wire so as not to
stretch brake hose.

Do not damage piston boot.

Burnish brake contact surface after refinishing or replacing rotors, after replacing pads, or it a soft
pedal occurs at very low mileage. Refer to BR-31, "
BRAKE BURNISHING PROCEDURE" .
Removal and Installation of Brake PadEFS003PU
REMOVAL
1. Remove tires from vehicle with power tool.
2. Remove mounting bolt from the top mount.
3. Swing cylinder body open, and remove pads.
INSTALLATION
1. Push piston in so that pad is firmly attached and mount cylinder body to torque member.
NOTE:
Using a disc brake piston tool (commercial service tool), makes it easier to push in the piston.
CAUTION:
By pushing in piston, brake fluid returns to master cylinder reservoir tank. Watch the level of the
surface of reservoir tank.
2. Install pads to cylinder body.
3. Install top mounting bolt and tighten to specification.
4. Check brake for drag.
5. Install tires to the vehicle. Refer to WT-6, "
Rotation"
Removal and Installation of Brake Caliper Assembly and Disc RotorEFS003PV
REMOVAL
1. Remove tires from vehicle with power tool.
2. Drain brake fluid as necessary. Refer to BR-10, "
Drain and Refill" .
NOTE:
Do not remove union bolt unless removing cylinder body from vehicle.
3. Remove mounting bolts and cylinder body.
NOTE:
Position cylinder body aside using suitable wire, as necessary.
4. Remove disc rotor.
INSTALLATION
CAUTION:

Refill with recommended brake fluid. Refer to MA-10, "RECOMMENDED FLUIDS AND LUBRI-
CANTS" .

Do not reuse drained brake fluid.
1. Install disc rotor.
2. Install cylinder body to the vehicle, and tighten mounting bolts to specification. Refer to BR-27, "
Compo-
nents" .
CAUTION:
Before installing cylinder body to the vehicle, wipe off mounting surface of cylinder body.
LFIA0211E

REAR DISC BRAKE
BR-29
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Revision: August 20072004 QX56
3. Install brake hose to cylinder body and tighten union bolt to specification as necessary. Refer to BR-27,
"Components" .
CAUTION:

Do not reuse copper washers.

Securely attach brake hose to protrusion on cylinder body.
4. Refill with new brake fluid and bleed air as necessary. Refer to BR-11, "
Bleeding Brake System" .
5. Install tires to the vehicle. Refer to WT-6, "
Rotation"
Disassembly and Assembly of Brake Caliper AssemblyEFS003PW
DISASSEMBLY
1. Remove pads from cylinder body.
2. Remove sliding sleeve and boot from cylinder body body.
3. Place a wooden block as shown in the figure, and blow air from
union bolt mounting hole to remove piston and piston boot.
CAUTION:
Do not get your fingers caught in piston.
4. Using a flat-bladed screwdriver, remove piston seal from cylin-
der body.
CAUTION:
Be careful not to damage cylinder body inner wall.
CALIPER INSPECTION
Cylinder Body
CAUTION:

Use new brake fluid to clean. Do not use mineral oils such as gasoline or kerosene.

Check inside surface of cylinder body for score, rust wear, damage or foreign materials. If any of
the above conditions are observed, replace cylinder body.

Minor damage from rust or foreign materials may be eliminated by polishing surface with a fine
emery paper. Replace cylinder body if necessary.
Torque Member
Check for wear, cracks, and damage. If damage or deformation is present, replace the affected part.
Piston
CAUTION:

Piston sliding surface is plated, do not polish with emery paper even if rust of foreign materials
are stuck to sliding surface.

Check piston for score, rust, wear, damage or presence of foreign materials. Replace if any of the
above conditions are observed.
Sliding Pin Bolts and Sliding Pin Boots
Make sure there is no wear, damage, or cracks in sliding sleeve and sliding sleeve boots, and if there are,
replace them.
BRD0041D
PFIA0269E

PRECAUTIONS
BRC-3
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EFS0062W
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WA RN ING:

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 inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI 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 SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for Brake System EFS003QB
CAUTION:

Always use recommended brake fluid. Refer to MA-10, "RECOMMENDED FLUIDS AND LUBRI-
CANTS" .

Never reuse drained brake fluid.

Be 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.

To clean or wash all parts of master cylinder and disc brake caliper, use clean brake fluid.

Never use mineral oils such as gasoline or kerosene. They will ruin rubber parts of the hydraulic
system.

Use flare nut wrench when removing and installing brake
tube.

If a brake fluid leak is found, the part must be disassembled
without fail. Then it has to be replaced with a new one if a
defect exists.

Turn the ignition switch OFF and remove the connector of
the ABS actuator control unit or the battery terminal before
performing the work.

Always torque brake lines when installing.

Burnish the brake contact surfaces after refinishing or
replacing rotors, after replacing pads, or if a soft pedal
occurs at very low mileage.
Refer to BR-25, "
BRAKE BURNISHING PROCEDURE" (front disc brake) or BR-31, "BRAKE BUR-
NISHING PROCEDURE" (rear disc brake).
WA RN ING:

Clean brake pads and shoes with a waste cloth, then wipe with a dust collector.
Precautions When Using CONSULT-IIEFS003QC
When connecting CONSULT-II to data link connector, connect them through CONSULT-II CONVERTER.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
CHECK POINTS FOR USING CONSULT-II
1. Has CONSULT-II been used without connecting CONSULT-II CONVERTER on this vehicle?
SBR6 86 C

BRC-6
[VDC/TCS/ABS]
PREPARATION
Revision: August 20072004 QX56
PREPARATIONPFP:00002
Special Service ToolEFS003QG
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEFS003QH
Tool number
(Kent-Moore No.)
Tool nameDescription
(J-45741)
ABS active wheel sensor testerChecking operation of ABS active wheel sen-
sors
WFIA0101E
Tool nameDescription
1. Flare nut crowfoot
2. Torque wrenchRemoving and installing brake piping
a: 10mm (0.39 in)/12mm (0.47 in)
S-NT360

BRC-8
[VDC/TCS/ABS]
SYSTEM DESCRIPTION
Revision: August 20072004 QX56
ABS FunctionEFS003QJ

The Anti-Lock Brake System detects wheel revolution while braking and improves handling stability during
sudden braking by electrically preventing wheel lockup. Maneuverability is also improved for avoiding
obstacles.

If the electrical system malfunctions, the Fail-Safe function is activated, the ABS becomes inoperative and
the ABS warning lamp turns on.

The electrical system can be diagnosed using CONSULT-II.

During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.

Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel,
or snow-covered (fresh, deep snow) roads.
EBD FunctionEFS003QK

Electronic Brake Distribution is a function that detects subtle slippages between the front and rear wheels
during braking, and it improves handling stability by electronically controlling the brake fluid pressure
which results in reduced rear wheel slippage.

If the electrical system malfunctions, the Fail-Safe function is activated, the EBD and ABS become inoper-
ative, and the ABS warning lamp and BRAKE warning lamp are turned on.

The electrical system can be diagnosed using CONSULT-II.

During EBD operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.
TCS FunctionEFS003QL

Spinning of the drive wheels is detected by the ABS actuator and electric unit (control unit) using inputs
from the wheel speed sensors. If wheel spin occurs, the drive wheel right and left brake fluid pressure
control and engine fuel cut are activated while the throttle value is restricted to reduce the engine torque
and decrease the amount of wheel spin. In addition, the throttle opening is controlled to achieve the opti-
mum engine torque.

Depending on road condition, the vehicle may have a sluggish feel. This is normal, because optimum trac-
tion has the highest priority during TCS operation.

TCS may be activated during sudden vehicle acceleration, wide open throttle acceleration, sudden trans-
mission shifts or when the vehicle is driven on a road with a varying surface friction coefficient.

The SLIP indicator lamp flashes to inform the driver of TCS operation.
VDC FunctionEFS003QM

In addition to the ABS/TCS function, the driver steering amount and brake operation amount are detected
from the steering angle sensor and front and rear pressure sensors, and the vehicle's driving status
(amount of under steering/over steering) is determined using inputs from the yaw rate sensor/side G sen-
sor, wheel speed sensors, etc. and this information is used to improve vehicle stability by controlling the
braking and engine torque application to the wheels.

The SLIP indicator lamp flashes to inform the driver of VDC operation.

During VDC operation, the vehicle body and brake pedal may vibrate lightly and a mechanical noise may
be heard. This is normal.

The ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp may turn on when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the
engine is running or on a steep slope. In this case, restart the engine on a normal road and if the ABS
warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn off, there is no problem.
Fail-Safe FunctionEFS003QN
CAUTION:
If the Fail-Safe function is activated, perform the Self Diagnosis for ABS/TCS/VDC system.

TROUBLE DIAGNOSIS
BRC-23
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
Basic InspectionEFS003QU
BRAKE FLUID LEVEL, FLUID LEAK, AND BRAKE PAD INSPECTION
1. Check fluid level in the brake fluid reservoir. If fluid level is low, add fluid.
2. Check the brake piping and around the ABS actuator and electric unit (control unit) for leaks. If there is
leaking or seeping fluid, check the following items.

If ABS actuator and electric unit (control unit) connection is loose, tighten the piping to the specified
torque and recheck for leaks.

If there is damage to the connection flare nut or ABS actuator and electric unit (control unit) threads,
replace the damaged part and recheck for leaks.

When there is fluid leaking or seeping from a fluid connection, use a clean cloth to wipe off the fluid and
recheck for leaks. If fluid is still seeping out, replace the damaged part. If the fluid is leaking at the ABS
actuator and electric unit (control unit), replace the ABS actuator and electric unit (control unit) assem-
bly.
CAUTION:
The ABS actuator and electric unit (control unit) cannot be disassembled and must be replaced
as an assembly.
3. Check the brake pads for excessive wear.
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION
Make sure the battery positive cable, negative cable and ground connection are not loose. In addition, make
sure the battery is sufficiently charged.
ABS WARNING LAMP, SLIP INDICATOR LAMP AND VDC OFF INDICATOR LAMP INSPECTION
1. Make sure ABS warning lamp, SLIP indicator lamp and VDC OFF indicator lamp (when VDC OFF switch
is off), turn on for approximately 2 seconds when the ignition switch is turned ON. If they do not, check the
VDC OFF indicator lamp and the VDC OFF switch. Refer to BRC-56, "
VDC OFF SWITCH" . Check CAN
communications. If there are no errors with the VDC OFF switch or CAN communication system, check
combination meter. Refer to DI-5, "
COMBINATION METERS" .
2. Make sure the lamps turn off approximately 2 seconds after the ignition switch is turned ON. If the lamp
does not turn off, conduct self-diagnosis.
3. With the engine running, make sure the VDC OFF indicator lamp turns on and off when the VDC OFF
switch is turned on and off. If the indicator lamp status does not correspond to switch operation, check the
VDC OFF switch. Refer to BRC-56, "
VDC OFF SWITCH" .
4. Make sure ABS warning lamp, SLIP indicator lamp and VDC OFF indicator lamp turn off approximately 2
seconds after the engine is started. If ABS warning lamp, SLIP indicator lamp or VDC OFF indicator lamp
have not turned off 10 seconds after the engine has been started, conduct self-diagnosis of the ABS actu-
ator and electric unit (control unit).
5. After conducting the self-diagnosis, be sure to erase the error memory. Refer to BRC-28, "
CONSULT-II
Function (ABS)" .

BRC-64
[VDC/TCS/ABS]
WHEEL SENSORS
Revision: August 20072004 QX56
WHEEL SENSORSPFP:47910
Removal and InstallationEFS003RO
REMOVAL
1. Remove wheel sensor mounting screw.

When removing the front wheel sensor, first remove the disc rotor to gain access to the front wheel sen-
sor mounting bolt. Refer to BR-22, "
Removal and Installation of Brake Caliper and Disc Rotor" .

When removing the rear wheel sensor, first remove the rear hub and bearing assembly to gain access
to the rear wheel sensor mounting bolt. Refer to RAX-5, "
Removal and Installation" .
2. Pull out the sensor, being careful to turn it as little as possible.
CAUTION:

Do not pull on the sensor harness.
3. Disconnect wheel sensor harness electrical connector, then remove harness from mounts.
INSTALLATION
Installation is in the reverse order of removal. Tighten wheel sensor bolt to the specified torque.
CAUTION:
Installation should be performed while paying attention to the following.

Inspect wheel sensor O-ring, replace sensor assembly if damaged.

Before installing wheel sensor, make sure no foreign materials (such as iron fragments) are
adhered to the pick-up part of the sensor, to the inside of the sensor mounting hole or on the rotor
mounting surface.

Apply a coat of suitable grease to the wheel sensor O-ring and mounting hole.
WFIA0240E