2011 INFINITI QX56 Eco

BR-18
< PERIODIC MAINTENANCE >
REAR DISC BRAKE
REAR DISC BRAKE
BRAKE PAD
BRAKE PAD : Inspection and AdjustmentINFOID:0000000006222470
INSPECTION
Check the thickness of brake pad from the inspection hole (A) on
brake caliper assembly. Check use a scale if necessary.
ADJUSTMENT
CAUTION:
 Burnish contact surfaces between pads according to the following procedure after refinishing or
replacing brake pads, or if a soft pedal occurs at very low mileage.
 Be careful of vehicle speed because the brake does not operate firmly/securely until pads and disc
rotor are securely fitted.
 Only perform this procedure under safe road and traffic conditions. Use extreme caution.
1. Drive vehicle on straight, flat road.
2. Depress brake pedal with the power to stop vehicl e within 3 to 5 seconds until the vehicle stops.
3. Drive without depressing brake for a few minutes to cool the brake.
4. Repeat steps 1 to 3 until pad and disc rotor are securely fitted.
DISC ROTOR
DISC ROTOR : Inspec tion and AdjustmentINFOID:0000000006222471
INSPECTION
Appearance
Check surface of disc rotor for uneven wear, cracks, and serious damage. Replace it if necessary. Refer to
RAX-7, "
Removal and Installation".
Runout
1. Fix the disc rotor to the wheel hub and bearing assembly with wheel nuts (2 points at least).
2. Check the wheel bearing axial end play before the inspection. Refer to RAX-5, "
Inspection".
3. Inspect the runout with a dial indicator to measure at 10 mm (0.39 in) inside the disc edge.
4. Find the installation position that has a minimum runout by shift-
ing the disc rotor-to-wheel hub and bearing assembly installation
position by one hole at a time if the runout exceeds the limit
value.
5. Refinish the disc rotor if the runout is outside the limit even after performing the above operation. [When refinishing, use the Pro-
Cut PEM On-Car brake Lathe (Tool No. 38-PFM90.5) or equiva-
lent.]
CAUTION:
 Check in advance that the thickn ess of the disc rotor is wear thickness + 0.3 mm (0.012 in) or
more. Wear thickness : Refer to
BR-47, "
Rear Disc Brake".
JPFIA0720ZZ
Runout : Refer to BR-47, "Rear Disc Brake".
JPFIA0721ZZ
Revision: 2010 May2011 QX56

REAR DISC BRAKEBR-19
< PERIODIC MAINTENANCE >
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 If the thickness is less than wear thickness + 0. 3 mm (0.012 in), replace the disc rotor. Refer to
RAX-7, "
Removal and Installation".
Thickness
Check the thickness of the disc rotor using a micrometer. Replace
the disc rotor if the thickness is below the wear limit. Refer to RAX-7,
"Removal and Installation".
ADJUSTMENT
CAUTION:
 Burnish contact surfaces between pads according to the following procedure after refinishing or
replacing brake pads, or if a soft pedal occurs at very low mileage.
 Be careful of vehicle speed because the brake does not operate firmly/securely until pads and disc
rotor are securely fitted.
 Only perform this procedure under safe road and traffic conditions. Use extreme caution.
1. Drive vehicle on straight, flat road.
2. Depress brake pedal with the power to stop vehicl e within 3 to 5 seconds until the vehicle stops.
3. Drive without depressing brake for a few minutes to cool the brake.
4. Repeat steps 1 to 3 until pad and disc rotor are securely fitted. Wear thickness : Refer to
BR-47, "
Rear Disc Brake".
Wear thickness : Refer to BR-47, "
Rear Disc Brake".
JPFIA0722ZZ
Revision: 2010 May2011 QX56

BR-32
< REMOVAL AND INSTALLATION >
HYDRAULIC BOOSTER ASSEMBLY
 Apply new brake fluid to grommet of between reservoir tank and grommet and ABS actuator and electric unit
(control unit).
Inspection and AdjustmentINFOID:0000000006222486
ADJUSTMENT BEFORE INSTALLATION
Input Rod Length adjustment
1. Loosen the lock nut (1) and adjust the input rod (2) to the speci-
fied length (A).
2. Tighten the lock nut to the specified torque.
INSPECTION AFTER INSTALLATION
Operation Check
1. Turn the ignition switch OFF.
2. Depress the brake pedal 20 times or more. NOTE:
The pressure loss in the accumulator results in a large brake pedal stroke. In addition to this, the brake
pedal depression becomes lighter in initial stage.
3. Check that the fluid level in the reservoir tank is MAX line.
4. Position the selector lever in P range to release the parking brake.
5. Turn the ignition switch ON to check the time between motor activation and motor stop.
6. After the motor is stopped, check that the ABS warn ing lamp and the VDC warning lamp in the combina-
tion meter are OFF when the engine is started.
7. Stop the engine (ignition switch OFF).
8. Turn the ignition switch ON and depress the brake pedal 4 to 5 times to check the time between motor activation and motor stop.
9. Turn the ignition switch OFF. Turn the ignition swit ch ON again. Check that the VDC warning lamp turns
ON when the brake pedal is depressed 15 to 20 times.
10. Check that the VDC warning lamp turns ON when the brake pedal is depressed 15 to 20 times after the lapse of 120 seconds or more after the ignition switch is turned ON again.
11. Perform the self-diagnosis for “ABS” with CONSULT- III and erase all the stored self-diagnosis results.
Function Check
1. Turn the ignition switch OFF.
2. Depress the brake pedal 20 times or more.
NOTE:
The pressure loss in the accumulator results in a large brake pedal stroke. In addition to this, the brake
pedal depression becomes lighter in initial stage.
3. Turn the ignition switch ON with the brake pedal depr essed to check that the clearance between the brake
pedal and the dash lower panel decreases. A : Refer to
BR-47, "
Brake Booster".
JPFIA0728ZZ
Motor operating time : 18 seconds or less
Motor operating time : 2 − 11 seconds
Revision: 2010 May2011 QX56

SERVICE DATA AND SPECIFICATIONS (SDS)
BR-47
< SERVICE DATA AND SPECIFICATIONS (SDS)
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SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
General SpecificationINFOID:0000000006222502
Unit: mm (in)
Brake PedalINFOID:0000000006222503
Unit: mm (in)
Brake BoosterINFOID:0000000006222504
Unit: mm (in)
Front Disc BrakeINFOID:0000000006222505
Unit: mm (in)
Rear Disc BrakeINFOID:0000000006222506
Unit: mm (in)
Front brake Cylinder bore diameter 50.8 (2.000)
× 2
Pad length × width × thickness 151.6 (5.97) × 56.5 (2.224) × 12.0 (0.472)
Rotor outer diameter × thickness 350 (13.78) × 30.0 (1.181)
Rear brake Cylinder bore diameter 48.1 (10894)
Pad length
× width × thickness 110.0 (4.43) × 41.0 (1.614) × 9.0 (0.354)
Rotor outer diameter × thickness 350 (13.78) × 20.0 (0.787)
Control valve Valve type Electric brake force distribution
Recommended brake fluid Refer to MA-10, "
Fluids and Lubricants".
Item Standard
Brake pedal height 168.5 (6.63) – 178.5 (7.03)
Depressed brake pedal height
[Depressing 490 N (50 kg, 110 lb) while turning the engine ON] 100 (3.94) or more
Clearance between stop lamp switch and brake switch threaded end and the
brake pedal bracket 0.2 (0.008) – 1.96 (0.0772)
Brake pedal play 3 (0.12) – 11 (0.43)
Item Standard
Input rod length 202.2 (7.96)
Item Limit
Brake pad Wear thickness 1.5 (0.059)
Disc rotor Wear thickness 28.5 (1.122)
Thickness variation (measured at 8 positions) 0.015 (0.0006)
Runout (with it attached to the vehicle) 0.053 (0.0021)
Item Limit
Brake pad Wear thickness 2.0 (0.079)
Disc rotor Wear thickness 18.0 (0.709)
Thickness variation (measured at 8 positions) 0.015 (0.0006)
Runout (with it attached to the vehicle) 0.05 (0.0020)
Revision: 2010 May2011 QX56

BRC-6
< PRECAUTION >[WITH VDC]
PRECAUTIONS
5. When the repair work is completed, re-connect bot
h battery cables. With the brake pedal released, turn
the push-button ignition switch from ACC position to ON position, then to LOCK position. (The steering
wheel will lock when the push-button igniti on switch is turned to LOCK position.)
6. Perform self-diagnosis check of all control units using CONSULT-III.
Precaution for Procedure without Cowl Top CoverINFOID:0000000006228176
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Brake SystemINFOID:0000000006222556
WARNING:
Clean any dust from the front brake and rear brake using a vacuum dust collector. Never blow by com-
pressed air.
 Brake fluid use refer to MA-10, "
Fluids and Lubricants".
 Never reuse drained brake fluid.
 Never spill or splash brake fluid on painted surfaces. Brake fluid may seriously damage paint. Wipe it off
immediately and wash with water if it gets on a painted surface.
 Always confirm the specified tightening torque when installing the brake pipes.
 After pressing the brake pedal more deeply or harder t han normal driving, such as air bleeding, check each
item of brake pedal. Adjust brake pedal if it is outside the standard value.
 Never use mineral oils such as gasoline or light oil to clean. They may damage rubber parts and cause
improper operation.
 Always loosen the brake tube flar e nut with a flare nut wrench.
 Tighten the brake tube flare nut to the specified torque with a crow-
foot (A) and torque wrench (B).
 Always connect the battery terminal when moving the vehicle.
 Turn the ignition switch OFF and disconnect the ABS actuator and
electric unit (control unit) harness connector or the battery negative
terminal before performing the work.
 Check that no brake fluid leakage is present after replacing the parts.
Precaution for Brak e Control SystemINFOID:0000000006222557
 Slight vibrations are felt on the brake pedal and the operation noises occur, when VDC function, TCS func-
tion, ABS function, EBD function, hill start assist function or brake limited slip differential (BLSD) function
operates. This is not a malfunction because it is caus ed by VDC function, TCS function, ABS function, EBD
function, hill start assist function or brake limited sl ip differential (BLSD) function that is normally operated.
 When starting engine or when starting vehicle just after starting engine, brake pedal may vibrate or motor
operating noise may be heard from engine compartment. This is normal condition.
 Brake stopping distance may become longer than models without ABS function depending on the road con-
ditions, when ABS function is operated on slippery r oad like rough road, gravel road or snowy road.
 When a malfunction is indicated, always collect info rmation from the customer about conditions of occur-
rence, estimate cause and perform operation. Check brake booster operation, brake fluid level and brake
fluid leakage, as well as electrical system.
 The optimum performance is achieved by control for V DC function, TCS function, ABS function, EBD func-
tion, hill start assist function or brake limited slip di fferential (BLSD) function when all of brakes, suspensions
PIIB3706J
JPFIA0001ZZ
Revision: 2010 May2011 QX56

PRECAUTIONSBRC-7
< PRECAUTION > [WITH VDC]
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and tires installed on the vehicle are the specified si ze and parts. Brake performance and controllability may
be negatively affected when other parts than the specified are installed.
 Brake stopping distance may become longer and steering stability may be negatively affected, when tires in
different size and combination or other parts than the specified are used.
 When a radio (including wiring), antenna and antenna lead line are located near ABS actuator and electric
unit (control unit), a malfunction or improper operation ma y occur for the control of VDC function, TCS func-
tion, ABS function, EBD function, hill start assist func tion or brake limited slip differential (BLSD) function.
 When the following items are replaced by other parts than genuine parts or modified, ABS warning lamp, brake warning lamp and VDC warning lamp may turn ON, and the control may not operate normally for VDC
function, TCS function, ABS function, EB D function, hill start assist function or brake limited slip differential
(BLSD) function.
- Suspension component parts (shock absorber, spring, bushing and others)
- Tire and wheel (other than the specified size)
- Brake component parts (brake pad, disc rotor, brake caliper and others)
- Engine component parts (ECM, muffler and others)
- Body reinforcement component parts (rollover bar, tower bar and others)
 When suspension, tire and brake component parts are excessively worn or deteriorated and the vehicle is
driven, ABS warning lamp, brake warning lamp and VDC warning lamp may tu\
rn ON, and the control may
not operate normally for VDC function, TCS function, ABS function, EBD function, hill start assist function or
brake limited slip differential (BLSD) function.
 ABS warning lamp, brake warning lamp and VDC warning lamp may turn ON, when only front wheel or rear wheel is rotated using a free roller. This is not a ma lfunction, because it is caused by wheel speed difference
between wheel that is rotated and wheel that is not rota ted. In this case, perform self-diagnosis, check self-
diagnosis results, and erase memory.
 When power supply voltage is not normal, ABS warning lamp, brake warning lamp and VDC warning lamp
turn ON. ABS actuator and electric unit (control unit) st ops control for VDC function, TCS function, ABS func-
tion, EBD function, hill start assist function or brake limited slip differential (BLSD) function. Ordinary brake
operates. After power supply returns to normal, ABS warning lamp, brake warning lamp and VDC warning
lamp turn OFF. The control becomes operative for VD C function, TCS function, ABS function, EBD function,
hill start assist function or brake li mited slip differential (BLSD) function.
 VDC warning lamp may turn ON and VDC function or TCS function may not normally operate, when driving
on a special road the is extremely slanted (bank in a circ uit course). This is not a malfunction if the status
returns to normal for VDC function or TCS function after the engine is started again. In this case, perform
self-diagnosis, check self-diagnosis results, and erase memory.
 A malfunction in yaw rate/side/decel G sensor syste m may be detected when the vehicle sharply turns dur-
ing a spin turn, acceleration turn or drift driving while VDC function or TCS function are OFF (VDC OFF
switch is pressed and VDC OFF indicator lamp is in ON st atus). This is not a malfunction if the status returns
to normal for VDC function or TCS function after the engine is started again. In this case, perform self-diag-
nosis, check self-diagnosis results, and erase memory
Precaution for Harness RepairINFOID:0000000006222558
 Solder the repair part, and wrap it with tape. [Twisted wire fray must be 110 mm (4.33 in) or less.]
SKIB8766E
Revision: 2010 May2011 QX56

BRC-24
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
Rear LH caliper Being returned to reservoir tank through ABS OUT valve, fluid pressure of rear LH caliper is decreased.
Component Parts and Function
*: Models with Advanced Driver Assistance System
CONDITION FOR TURN ON THE WARNING LAMP
ABS Warning Lamp
 Turns ON at the same time as VDC warning lamp
when either ABS function or EBD function is malfunction-
ing.
 Turns ON when ignition switch turns ON and turns OFF when the system is normal, for bulb check purposes.
Brake Warning Lamp
 Turns ON at the same time as ABS warning lamp and VDC warning lamp when EBD function, motor/accu- mulator assembly or motor system is malfunctioning.
 Turns ON when ignition switch turns ON and turns OFF when the system is normal, for bulb check purposes.
Component Function
Pump Operates the pump drive according
to signals from ABS actuator and electric unit (control unit) by
the motor.
Motor Operates the motor driv e according to signals from ABS actuator and electric unit (control unit).
Accumulator The accumulator accumulates brake fluid conveyed by the motor and pump.
ABS IN valve Increases, holds or decreases the fluid pressure of each caliper according to signals from ABS ac-
tuator and electric unit (control unit).
ABS OUT valve Increases, holds or decreases the fluid pressure of each caliper according to signals from ABS ac-
tuator and electric unit (control unit).
Cut valve 1
Cut valve 2 Shuts off the ordinary brake line fr
om master cylinder to signals from ABS actuator and electric unit
(control unit).
Suction valve 1 Suction Valve 1 switches the brake line to convey accumulator pressure to the front system, accord-
ing to a signal transmitted from the ABS ac
tuator and electric unit (control unit).
Suction valve 2 Suction valve 2 releases
accumulator pressure, acco rding to a signal transmitted from the ABS ac-
tuator and electric unit (control unit).
Control pressure sensor
*Detects the brake fluid pressure of rear brake caliper and transmits a signal to ABS actuator and
electric unit (control unit).
Accumulator pressure sensor The accumulator pressure sensor detects brake fluid pressure accumulated in the accumulator and
conveys the detected result to the ABS actuator and electric unit (control unit).
Master cylinder pressure sensor Detects the brake fluid pressure of master cylinder part and transmits a signal to ABS actuator and
electric unit (control unit).
Condition (status) ABS warning lamp
Ignition switch OFF OFF
For approx. 1 seconds after the ignition switch is turned ON ON
Approx. 1 seconds after ignition switch is turned ON (when the
system is in normal operation) OFF
ABS function is ma lfunctioning ON
EBD function is malfunctioning ON
Condition (status) Brake warning lamp
Ignition switch OFF OFF
For approx. 1 seconds after the ignition switch is turned ON ON
Approx. 1 seconds after ignition switch is turned ON (when the
system is in normal operation) OFF
After engine starts OFF
When parking brake operates (parking brake switch ON) ON
Revision: 2010 May2011 QX56

SYSTEMBRC-25
< SYSTEM DESCRIPTION > [WITH VDC]
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VDC Warning Lamp
 Turns ON when either VDC function,
TCS function, ABS function or EBD function, hill start assist function or
brake limited slip differential (BLSD) function is malfunctioning.
 Turns ON when ignition switch turns ON and turns OFF when the system is normal, for bulb check purposes.
CONDITION FOR TURN ON THE INDICATOR LAMP
VDC OFF Indicator Lamp
 Turns ON when VDC function and TCS function are s witched to non-operational status (OFF) by VDC OFF
switch.
 Turns ON when ignition switch turns ON and turns OFF when the system is normal, for bulb check purposes.
*: Models with 4WD system
Fail-safeINFOID:0000000006228184
VDC FUNCTION, TCS FUNCTION, hill start assi st FUNCTION AND BRAKE LIMITED SLIP DIFFER-
ENTIAL (BLSD) FUNCTION
VDC warning lamp in combination meter turn ON w hen a malfunction occurs in system [ABS actuator and
electric unit (control unit)]. The control is suspended for VDC function, TCS function, hill start assist function
and brake limited slip differential (BLSD) function. T he Vehicle status becomes the same as models without
VDC function, TCS function, hill star t assist function and brake limited slip differential (BLSD) function. How-
ever, ABS function and EBD f unction are operated normally.
When brake fluid is less than the specified level (brake fluid level
switch ON) ON
ABS function is malfunctioning OFF
EBD function is malfunctioning ON
Accumulator is low pressure ON
Motor system is malfunctioning ON
Ignition power supply system is malfunctioning ON Condition (status) Brake warning lamp
Condition (status) VDC warning lamp
Ignition switch OFF OFF
For approx. 1 seconds after the ignition switch is turned ON ON
Approx. 1 seconds after ignition switch is turned ON (when the
system is in normal operation) OFF
VDC function is malfunctioning ON
TCS function is malfunctioning ON
ABS function is malfunctioning ON
EBD function is malfunctioning ON
hill start assist function is malfunctioning ON
Brake limited slip differential (BLSD) function is malfunctioning ON
VDC function is operating Blinking
TCS function is operating Blinking
Condition (status) VDC OFF indicator lamp
Ignition switch OFF OFF
For approx. 1 seconds after the ignition switch is turned ON ON
Approx. 1 seconds after ignition switch is turned ON (when the
system is in normal operation) OFF
When VDC OFF switch is ON (VDC function and TCS function are
OFF) ON
4WD mode: 4L
*ON
Revision: 2010 May2011 QX56