2004 INFINITI QX56 lock

BRAKE PIPING AND HOSE
BR-13
C
D
E
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MA
B
BR
Revision: August 20072004 QX56
INSTALLATION
1. Install brake hose by aligning with the protrusion on caliper
assembly, and tighten union bolt.
CAUTION:
Do not reuse copper washer.
2. Insert brake hose end through bracket, then secure it to bracket
with lock plate.
3. Install brake tube to brake hose, then tighten flare nut using a
flare nut wrench.
4. Refill brake fluid and bleed air. Refer to BR-11, "
Bleeding Brake
System" .
Removal and Installation of Rear Brake Hose EFS003PE
REMOVAL
1. Drain brake fluid. Refer to BR-10, "Drain and Refill" .
2. Using a flare nut wrench, remove brake tube from brake hose.
3. Remove lock plate and brake hose from bracket.
4. Remove union bolt, and then remove brake hose from caliper assembly.
INSTALLATION
1. Install brake hose by aligning with the protrusion on caliper
assembly, and tighten union bolt.
CAUTION:
Do not reuse copper washers.
2. Insert brake hose end through bracket, then secure it to bracket
with lock plate.
3. Install brake tube to brake hose, then tighten flare nut to using a
flare nut wrench.
4. Refill brake fluid and bleed air. Refer to BR-11, "
Bleeding Brake
System" .
LFIA0214E
LFIA0213E
LFIA0212E
LFIA0213E

BR-18
BRAKE BOOSTER
Revision: August 20072004 QX56
Removal and InstallationEFS003PK
REMOVAL
CAUTION:

Be careful not to deform or bend brake piping while removing and installing brake booster.

Replace clevis pin if it is damaged.

Be careful not to damage brake booster stud bolt threads. If brake booster is tilted or inclined dur-
ing installation, dash panel may damage the threads.

Attach the check valve in the correct direction.
1. Remove engine room cover with power tool. Refer to EM-11, "
Removal and Installation" .
2. Remove engine air duct assembly. Refer to EM-14, "
Removal and Installation" .
3. Remove brake piping from brake master cylinder.
4. Remove brake master cylinder. Refer to BR-15, "
Removal and Installation" .
5. Remove vacuum hose from brake booster. Refer to BR-20, "
VACUUM LINES" .
6. Disconnect active boost and delta stroke sensor harness connectors from brake booster assembly.
7. Remove brake pedal attachment snap pin and clevis pin from inside the vehicle.
8. Remove nuts on brake booster and brake pedal assembly.
9. Remove brake booster assembly from dash panel.
INSPECTION AFTER REMOVAL
Output Rod Length Inspection
1. Using a handy vacuum pump, apply a vacuum of – 66.7 kPa (–
500 mmHg, –19.69 inHg) to brake booster.
2. Check output rod length.
1. Reservoir tank 2. Brake master cylinder 3. Gasket
4. Brake pedal 5. Lock nut 6. Spacer block
7. Brake booster 8. Active booster 9. Delta stroke sensor
WFIA0233E
Standard dimension when
vacuum – 66.7 kPa (– 500
mmHg, – 19.69 inHg): 15.6 − 15.9 mm
(0.614 − 0.626 in)
SBR2 08 E

BRAKE BOOSTER
BR-19
C
D
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MA
B
BR
Revision: August 20072004 QX56
INSTALLATION
1. Loosen lock nut to adjust input rod length so that the length B (in
the figure) satisfies the specified value.
2. After adjusting “B”, temporarily tighten lock nut and install
booster assembly to the vehicle.

Install a gaskets and spacer block between booster assembly
and the dash panel.
3. Connect brake pedal with clevis of input rod.
4. Install pedal bracket mounting nuts and tighten them to the
specified torque.
5. Install brake piping from brake master cylinder to ABS actuator. Refer to BR-12, "
Hydraulic Circuit" .
6. Connect active boost and delta stroke sensor harness connectors to brake booster assembly.
7. Connect vacuum hose to brake booster.
8. Install master cylinder to booster assembly. Refer to BR-18, "
Removal and Installation" .
9. Adjust the height and play of brake pedal.
10. Tighten lock nut of input rod to the specified torque.
11. Install engine air duct assembly. Refer to EM-14, "
Removal and Installation" .
12. Install engine room cover with power tool. Refer to EM-11, "
Removal and Installation" .
13. Refill with new brake fluid and bleed air. Refer to BR-11, "
Bleeding Brake System" . Length “B” : 125 mm (4.92 in)
SGIA0060E

FRONT DISC BRAKE
BR-23
C
D
E
G
H
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K
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MA
B
BR
Revision: August 20072004 QX56
INSTALLATION
CAUTION:

Refill with new brake fluid. Refer to MA-10, "RECOMMENDED FLUIDS AND LUBRICANTS" .

Do not reuse drained brake fluid.
1. Install disc rotor.
2. Install torque member and tighten to specification. Refer to BR-21, "
Components" .
3. Install sliding pin bolts, if removed.
4. Install cylinder body, then tighten sliding pin bolts to the specified
torque. Refer to BR-21, "
Components" .
CAUTION:

When attaching cylinder body to the vehicle, wipe any oil
off knuckle spindle, washers and cylinder body attach-
ment surfaces.

Do not reuse cylinder body torque member bolts.
5. Install brake hose to cylinder body, if removed, then tighten
union bolt to the specified torque. Refer to BR-21, "
Compo-
nents" .
CAUTION:

Do not reuse copper washers for union bolt.

Attach brake hose to cylinder body together with union
bolt and washers.
6. Refill new brake fluid and bleed air. Refer to BR-11, "
Bleeding Brake System" .
7. Install wheel and tire. Refer to WT-6, "
Rotation" .
Disassembly and Assembly of Brake Caliper AssemblyEFS003PR
DISASSEMBLY
1. Remove sliding pin bolt, and then remove the pad, shim, shim cover, and pad retainer from the torque
member.
2. Remove sliding pins and sliding pin boots from torque member.
3. Place a wooden block as shown in the figure, and blow air from
union bolt mounting hole to remove pistons and piston boots.
CAUTION:
Do not get your fingers caught in piston.
LFIA0209E
LFIA0214E
MAA0272D

REAR DISC BRAKE
BR-29
C
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MA
B
BR
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

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.

OVERHEATING CAUSE ANALYSIS
CO-5
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MA
CO
Revision: August 20072004 QX56
Except cool-
ing system
parts mal-
function— Overload on engineAbusive drivingHigh engine rpm under no
load
Driving in low gear for
extended time
Driving at extremely high
speed
Powertrain system mal-
function
— Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flowBlocked bumper —
— Blocked radiator grilleInstalled car brassiere
Mud contamination or
paper clogging
Blocked radiator —
Blocked condenser
Blocked air flow
Installed large fog lamp Symptom Check items

WATER PUMP
CO-15
C
D
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F
G
H
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K
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MA
CO
Revision: August 20072004 QX56
WATER P UM PPFP:21020
Removal and InstallationEBS00I53
CAUTION:

When removing water pump, be careful not to get engine coolant on drive belt.

Water pump cannot be disassembled and should be replaced as a unit.
REMOVAL
1. Drain engine coolant so that no engine coolant comes out from water pump fitting hole. Refer to MA-12,
"DRAINING ENGINE COOLANT" .
CAUTION:
Perform when the engine is cold.
2. Remove the engine front undercover using power tool.
3. Remove the air duct and resonator assembly. Refer to EM-14, "
Removal and Installation" .
4. Remove the drive belt. Refer to EM-12, "
Removal and Installation" .
5. Remove the water pump pulley.
6. Remove the water pump.

Engine coolant will leak from the cylinder block, so have a receptacle ready below.
CAUTION:
Handle water pump vane so that it does not contact any other parts.
INSPECTION AFTER REMOVAL

Visually check that there is no significant dirt or rusting on the
water pump body and vane.

Make sure there is no looseness in the vane shaft, and that it
turns smoothly when rotated by hand.

If there are any unusual concerns, replace the water pump
assembly.
INSTALLATION
Installation is in the reverse order of removal.
KBIA2543E
1. Gasket 2. Water pump 3. Water pump pulley
KBIA2552E