2004 INFINITI QX56 Air

BR-10
BRAKE FLUID
Revision: August 20072004 QX56
BRAKE FLUIDPFP:KN100
On-board InspectionEFS003P9
LEVEL CHECK

Make sure the fluid level in reservoir tank is within the standard
(between MAX and MIN lines).

Visually check around reservoir tank for fluid leaks.

If fluid level is excessively low, check brake system for leaks.

If brake warning lamp remains illuminated after parking lever is
released, check brake system for fluid leakage.
Drain and RefillEFS003PA
CAUTION:

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

Do not reuse drained brake fluid.

Do not let brake fluid splash on the painted surfaces of the body. This might damage the paint, so
when splashing it, immediately wipe off the area and wash away with water.

Before servicing, disconnect actuator connector or battery negative cable.
1. Connect a vinyl tube to each bleed valve.
2. Depress brake pedal, loosen each bleed valve, and gradually
remove brake fluid.
3. Make sure there is no foreign material in reservoir tank, and refill
with new brake fluid.
4. Rest foot on brake pedal. Loosen bleed valve. Slowly depress
pedal until it stops. Tighten bleed valve. Release brake pedal.
Repeat this process a few times, then pause to add new brake
fluid to master cylinder. Continue until new brake fluid flows out.
Bleed air from brake system. Refer to BR-11, "
Bleeding Brake
System" .
LFIA0225E
SBR4 19 C
SBR9 95

BRAKE FLUID
BR-11
C
D
E
G
H
I
J
K
L
MA
B
BR
Revision: August 20072004 QX56
Bleeding Brake SystemEFS003PB
CAUTION:
While bleeding, pay attention to master cylinder fluid level.
1. Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector or battery
negative cable.
2. Connect a vinyl tube to the rear right bleed valve.
3. Fully depress brake pedal 4 to 5 times.
4. With brake pedal depressed, loosen bleed valve to let the air out, and then tighten it immediately.
5. Repeat steps 3 and 4 until no more air comes out.
6. Tighten bleed valve to the specified torque. Refer to BR-21, "
Components" (front disc brake), BR-27,
"Components" (rear disc brake).
7. Repeat steps 2 through 6, with master cylinder reservoir tank filled at least half way, bleed air from the
front left, rear left, and front right bleed valve.

BRAKE PIPING AND HOSE
BR-13
C
D
E
G
H
I
J
K
L
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-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
G
H
I
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