INFINITI QX56 2004 Factory Service Manual

BR-12
BRAKE PIPING AND HOSE
Revision: August 20072004 QX56
BRAKE PIPING AND HOSEPFP:46210
Hydraulic CircuitEFS003PC
CAUTION:

All hoses and tubes must be free from excessive bending, twisting and pulling.

Make sure there is no interference with other parts when turning steering both clockwise and
counterclockwise.

The brake piping is an important safety part. If a brake fluid leak is detected, always disassemble
the parts. Replace applicable part with a new one, if necessary.

Be careful not to splash brake fluid on painted areas; it way cause paint damage. If brake fluid is
splashed on painted areas, wash it away with water immediately.

Do not bend or twist brake hose sharply, or strongly pull it.

When removing components, cover connections so that no dirt, dust, or other foreign matter gets
in.

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

Do not reuse drained brake fluid.
Removal and Installation of Front Brake Hose EFS003PD
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.
1. Actuator 2. Master cylinder 3. Brake booster
4. Connector
WFIA0278E

BRAKE PIPING AND HOSE
BR-13
C
D
E
G
H
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K
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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-14
BRAKE PIPING AND HOSE
Revision: August 20072004 QX56
Inspection After InstallationEFS003PF
CAUTION:
If a leak is detected at the connections, retighten it or, if necessary, replace the damaged part.
1. Check brake tubes and hose connections for fluid leaks, damage, twist, deformation, contact with other
parts, and loose connections. Replace any damage parts.
2. While depressing brake pedal under a force of 785 N (80 kg, 177 lb) with engine running for approximately
5 seconds, check for fluid leakage from each part.

BRAKE MASTER CYLINDER
BR-15
C
D
E
G
H
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J
K
L
MA
B
BR
Revision: August 20072004 QX56
BRAKE MASTER CYLINDERPFP:46010
On-board InspectionEFS003PG
LEAK INSPECTION

Check for leaks at brake master cylinder to brake booster attachment point, reservoir tank, and brake tube
connections.
Removal and InstallationEFS003PH
CAUTION:
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.
REMOVAL
1. Drain brake fluid. Refer to BR-10, "Drain and Refill" .
2. Disconnect harness connectors for fluid level sensor and pressure sensors.
3. Using a flare nut wrench, disconnect brake tube from brake master cylinder.
4. Remove brake master cylinder mounting nuts, and master cylinder assembly.
1. Reservoir cap 2. Fluid level sensor 3. Grommet
4. Master cylinder sub-assembly 5. Front pressure sensor 6. Rear pressure sensor
7. Reservoir tank 8. Seal
WFIA0378E

BR-16
BRAKE MASTER CYLINDER
Revision: August 20072004 QX56
INSTALLATION

Installation is in the reverse order of removal.

Refill brake fluid and bleed air. Refer to BR-11, "Bleeding Brake System" .
CAUTION:

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

Do not reuse drained brake fluid.

Adjust brake pedal. Refer to BR-7, "ADJUSTMENT" .
Disassembly and AssemblyEFS003PI
DISASSEMBLY
CAUTION:

Master cylinder cannot be disassembled.

Remove reservoir tank only when absolutely necessary.
Pull reservoir tank off master cylinder sub-assembly, then remove grommets from master cylinder sub-assem-
bly body.
ASSEMBLY
CAUTION:

Never use mineral oil such as kerosene, gasoline during the cleaning and assembly process.

Do not drop parts. If a part is dropped, do not use it.
1. Apply brake fluid or rubber grease to new grommets, then insert into master cylinder sub-assembly. Refer
to GI-45, "
RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS" .
CAUTION:
Do not reuse grommet.
2. Install reservoir tank onto master cylinder sub-assembly.

BRAKE BOOSTER
BR-17
C
D
E
G
H
I
J
K
L
MA
B
BR
Revision: August 20072004 QX56
BRAKE BOOSTERPFP:47200
On-Vehicle ServiceEFS003PJ
OPERATING CHECK
With engine stopped, change the vacuum to the atmospheric pres-
sure by depressing brake pedal several times. Then with brake
pedal fully depressed, start engine and when the vacuum pressure
reaches the standard, make sure the clearance between brake pedal
and floor panel decreases.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
AIRTIGHT CHECK

Run engine at idle for approximately 1 minute, and stop it after
applying vacuum to booster. Depress brake pedal normally to
change the vacuum to the atmospheric pressure. Make sure dis-
tance between brake pedal and floor panel gradually increases.

Depress brake pedal while engine is running and stop engine
with pedal depressed. The pedal stroke should not change after
holding pedal down for 30 seconds.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
BRA0037D
SBR3 65 AA

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
E
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H
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J
K
L
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

BR-20
VACUUM LINES
Revision: August 20072004 QX56
VACUUM LINESPFP:41920
Removal and InstallationEFS003PL
1. Disconnect vacuum hose from hose clip.
2. Release clamps and disconnect vacuum hose.
3. Remove check valve from brake booster.
4. Installation is in the reverse order of removal.
CAUTION:

Insert vacuum hose for at least 24 mm (0.94 in).

Do not use lubricating oil during assembly.
InspectionEFS003PM
VISUAL INSPECTION
Check for improper assembly, damage and deterioration.
CHECK VALVE INSPECTION
Airtightness Inspection
Use a suitable vacuum pump to check. Connect to brake booster
side of check valve.
1. Hose clip 2. Clamp 3. Vacuum hose
4. Check valve
LFIA0216E
SBR2 25 B
Check
valve
specifi-
cation: Vacuum decrease should be within 1.3
kPa (10 mmHg, 0.39 inHg) for 15 seconds
under a vacuum of – 66.7 kPa (– 500 mmHg,
– 19.69 inHg)
LFIA0217E

FRONT DISC BRAKE
BR-21
C
D
E
G
H
I
J
K
L
MA
B
BR
Revision: August 20072004 QX56
FRONT DISC BRAKEPFP:41000
On-vehicle InspectionEFS003PN
PAD WEAR INSPECTION

Inspect the thickness of pad through cylinder body inspection
hole. Use a scale for inspection if necessary.
ComponentsEFS003PO
Standard thickness : 11.88 mm (0.468 in)
Repair limit thickness : 1.0 mm (0.039 in)
BRA0010D
1. Upper sliding pin 2. Sliding pin boot 3. Torque member bolt
4. Torque member 5. Piston seal 6. Piston
7. Inner pad 8. Pad retainer 9. Outer pad
10. Piston boot 11. Union bolt 12. Copper washer
13. Sliding pin bolt 14. Bleed valve 15. Cylinder body
16. Cap 17. Brake hose 18. Lower sliding pin
WFIA0393E