torque INFINITI QX56 2011 Factory Owner's Manual

REAR DISC BRAKEBR-43
< REMOVAL AND INSTALLATION >
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DISASSEMBLY
BRAKE CALIPER ASSEMBLY : Removal and InstallationINFOID:0000000006222499
REMOVAL
WARNING:
Clean any dust from the brake caliper assembly an d brake pads with a vacuum dust collector. Never
blow with compressed air.
1. Brake caliper assembly
Refer to GI-4, "
Components" for symbols in the figure.
JPFIA0735GB
1. Cap 2. Bleeder valve 3. Cylinder body
4. Piston seal 5. Piston 6. Piston boot
7. Sliding pin 8. Bushing 9. Sliding pin boot
10. Torque member
: Apply rubber grease.
: Apply brake fluid
Refer to GI-4, "
Components" for symbols not described on the above.
JPFIA0736GB
Revision: 2010 May2011 QX56

BR-44
< REMOVAL AND INSTALLATION >
REAR DISC BRAKE
CAUTION:
 Never spill or splash brake fluid on painted surfaces. Brake fluid may seriously damage paint. Wipe it
off immediately and wash with wate r if it gets on a painted surface.
 Never depress the brake pedal. Brake fluid may splash while removing the brake hose.
 If the brake fluid or grease adheres to the brake calip er assembly and disc rotor, quickly wipe it off.
1. Remove tires with power tool.
2. Fix the disc rotor using wheel nuts.
3. Drain brake fluid. Refer to BR-10, "
Draining".
4. Separate brake hose from brake caliper assembly. Refer to BR-26, "
REAR : Removal and Installation".
5. Remove torque member mounting bolts, and remove brake caliper assembly. CAUTION:
Never drop brake pad and caliper assembly.
6. Remove disc rotor. Refer to RAX-7, "
Removal and Installation".
INSTALLATION
WARNING:
Clean any dust from the brake caliper assembly an d brake pads with a vacuum dust collector. Never
blow with compressed air.
CAUTION:
 Never spill or splash brake fluid on painted surfaces. Brake fluid may seriously damage paint. Wipe it
off immediately and wash with wate r if it gets on a painted surface.
 Never depress the brake pedal. Brake fluid may splash while removing the brake hose.
 If the brake fluid or grease adheres to the brake calip er assembly and disc rotor, quickly wipe it off.
1. Install disc rotor. Refer to RAX-7, "
Removal and Installation".
2. Install the brake caliper assembly to the axle hous ing and tighten the torque member mounting bolts to the
specified torque.
CAUTION:
Never spill or splash any grease and moisture on the brake caliper assembly mounting face,
threads, mounting bolts. Wipe out any grease and moisture.
3. Install brake hose to brake caliper assembly. Refer to BR-26, "
REAR : Removal and Installation".
4. Perform the air bleeding. Refer to BR-11, "
Bleeding Brake System".
5. Check a drag of rear disc brake. If any drag is found, refer to BR-45, "
BRAKE CALIPER ASSEMBLY :
Inspection".
6. Install tires with power tool. Refer to WT-64, "
Exploded View".
BRAKE CALIPER ASSEMBLY : Disassembly and AssemblyINFOID:0000000006222500
DISASSEMBLY
NOTE:
Never remove the torque member, brake pads and pad retainers when disassembling and assembling the cyl-
inder body.
1. Remove the sliding pin bolt, and remove the cylinder body from the torque member.
CAUTION:
Fix the brake pad at suitable tape so that the brake pad will not drop.
2. Remove sliding pin boots from torque member.
3. Remove bushing from sliding pin bolt.
4. Place a wooden block as shown in the figure, and blow air from brake hose mounting hole to remove piston and piston boot.
CAUTION:
Never get fingers caught in the piston.
MAA0272D
Revision: 2010 May2011 QX56

REAR DISC BRAKEBR-45
< REMOVAL AND INSTALLATION >
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5. Remove piston seal from cylinder body using suitable tool. CAUTION:
Be careful not to damage a cylinder inner wall.
6. Remove bleeder valve and cap.
7. Perform inspection after disassembly. Refer to BR-45, "
BRAKE
CALIPER ASSEMBLY : Inspection".
ASSEMBLY
1. Install bleeder valve and cap.
2. Apply rubber grease to piston seal (1), and install them to cylin-
der body.
CAUTION:
Never reuse piston seal.
3. Apply rubber grease to piston boot (1). Cover the piston (2) end with piston boot, and then install cylinder side lip on piston boot
securely into a groove on cylinder body.
CAUTION:
Never reuse piston boot.
4. Apply new brake fluid to piston (1). Push piston into cylinder body by hand and push piston boot (2) piston-side lip into the
piston groove.
CAUTION:
Press the piston evenly and var y the pressing point to pre-
vent cylinder inner wall from being rubbed.
5. Apply rubber grease to bushing, and install bushing to sliding pin bolt.
6. Apply rubber grease to sliding pin boots, and install sliding pin boots to torque member.
7. Apply rubber grease to sliding pin, and install the cylinder body.
8. Install sliding pin bolts and tighten it to the specified torque.Refer to BR-42, "
BRAKE CALIPER ASSEM-
BLY : Exploded View".
BRAKE CALIPER ASSEMBLY : InspectionINFOID:0000000006222501
INSPECTION AFTER DISASSEMBLY
Check the following items and replace if necessary.
Cylinder Body
Check the cylinder inner wall for rust, wear, cracks or damage.
JPFIA0738ZZ
JPFIA0039ZZ
JPFIA0739ZZ
JPFIA0034ZZ
Revision: 2010 May2011 QX56

BR-46
< REMOVAL AND INSTALLATION >
REAR DISC BRAKE
CAUTION:
Always clean with new brake fluid. Never clean with mineral oil such as gasoline and light oil.
Torque Member
Check the torque member for rust, wear, cracks or damage.
Piston
Check the surface of the piston for rust, wear, cracks or damage.
CAUTION:
A piston sliding surface is plat ed. Never polish with sandpaper.
Sliding Pin, Sliding Pin Boot and Bushing
Check the sliding pins, sliding pin boots and bushing for rust, wear, cracks or damage.
INSPECTION AFTER INSTALLATION
1. Check a drag of rear disc brake. If any dr ag is found, follow the procedure described below.
2. Remove brake pads. Refer to BR-41, "
BRAKE PAD : Removal and Installation".
3. Press the piston. Refer to BR-41, "
BRAKE PAD : Removal and Installation".
4. Install brake pads. Refer to BR-41, "
BRAKE PAD : Removal and Installation".
5. Depress the brake pedal several times.
6. Check a drag of rear disc brake again. If any drag is found, disassemble the caliper. Refer to BR-44,
"BRAKE CALIPER ASSEMBLY : Disassembly and Assembly".
7. Burnish contact surfaces brake pads and disc rotor after refinishing or replacing disc rotor, or if a soft pedal occurs at very low mileage. Refer to BR-18, "
DISC ROTOR : Inspection and Adjustment".
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

SYSTEMBRC-31
< SYSTEM DESCRIPTION > [WITH VDC]
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 During a cornering, brake force (brake fluid pressu re) is applied on front wheel and rear wheel on the inner
side of turn. Moment directing towards the inner side of turn is generated. Understeer is prevented.
 Applying braking during a cornering on a slippery road, when understeer tendency is judged large, engine
output is controlled as well as brake force (brake fluid pressure) of four wheels. Understeer tendency
decreases.
TCS FUNCTION
TCS FUNCTION : System DescriptionINFOID:0000000006222573
 Wheel spin status of drive wheel is detected by wheel sensor of 4
wheels. Engine output and transmission shift status is controlled
so that slip rate of drive wheels is in appropriate level. When wheel
spin occurs on drive wheel, ABS ac tuator and electric unit (control
unit) perform brake force control of LH and RH drive wheels (apply
brake force by increasing brake fluid pressure of drive wheel) and
decrease engine torque by engine torque control. Wheel spin
amount decreases. Engine torque is controlled to appropriate
level.
 TCS function can be switched to non-operational status (OFF) by
operating VDC OFF switch. In this case, VDC OFF indicator lamp
turns ON.
 TCS function is not operate when 4WD mode is “4L”. (Models with
4WD system)
 VDC warning lamp blinking while TCS function is in operation and indicates to the driver that the function is in operation.
 Slight vibrations are felt on the brake pedal and the operation noises occur, when TCS function operates. This is not a malfunc-
tion because it is caused by TCS function that is normally oper-
ated.
 CONSULT-III can be used to diagnose the system diagnosis.
 Fail-safe function is adopted. W hen a malfunction occurs in TCS
function, the control is suspended for VDC function, TCS function,
hill start assist function and brake limited slip differential (BLSD)
function. The vehicle status becomes the same as models without VDC function, TCS function, hill start
assist function and brake limited slip differential (B LSD) function. However, ABS function and EBD function
are operated normally. Refer to BRC-25, "
Fail-safe".
SYSTEM DIAGRAM
NOTE:
JPFIC0137GB
JPFIC0138GB
JPFIC0139GB
Revision: 2010 May2011 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-137
< REMOVAL AND INSTALLATION > [WITH VDC]
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ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Removal and InstallationINFOID:0000000006222676
REMOVAL
1. Remove hydraulic booster assembly. Refer to BR-29, "Removal and Installation".
CAUTION:
After replacing the hydraulic booster assembly or motor/accumulator assembly, always follow the
accumulator disposal procedure to discard the hydraulic booster assembly or motor/accumulator
assembly. Refer to BR-33, "
Disposal".
2. Remove ABS actuator and electric unit (control unit). Refer to BR-30, "
Disassembly and Assembly".
INSTALLATION
Note the following, and install in the reverse order of removal.
 When installing brake tube, tighten to the specified torque using a crowfoot and torque wrench so that flare
nut and brake tube are not damaged. Refer to BR-22, "
FRONT : Exploded View".
 Never remove and install hydraulic booster assembly by holding harness.
 Bleed air from brake piping after installation. Refer to BR-11, "
Bleeding Brake System".
 Never apply excessive impact to hydraulic booster assembly, such as by dropping it.
 Check that connector is fully locked after hydraul ic booster assembly harness connector is installed.
 Perform decel G sensor calibration when hydraulic boos ter assembly [ABS actuator and electric unit (control
unit)] is replaced. Refer to BRC-66, "
Work Procedure".
Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-143
< SYSTEM DESCRIPTION > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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Component DescriptionINFOID:0000000006248457
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of instrument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pressure cont rol signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (c
ontrol unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (c ontrol unit) controls the brake,
based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

BRC-150
< SYSTEM DESCRIPTION >[INTELLIGENT BRAKE ASSIST]
COMPONENT PARTS
Component Description
INFOID:0000000006248459
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of inst rument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pres sure control signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (control unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (control unit) controls the brake, based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

REPAIRING HIGH STRENGTH STEELBRM-5
< PRECAUTION >
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 The repair of reinforcements (such as side members) by heat- ing is not recommended, because it may weaken the compo-
nent. When heating is unavoidable, never heat HSS parts
above 550 °C (1,022 °F).
Verify heating temperature with a thermometer.
(Crayon-type and other similar type thermometer are appropri-
ate.)
 When straightening body panels, use caution in pul ling any HSS panel. Because HSS is very strong,
pulling may cause deformation in adjacent sections of the body. In this case, increase the number of
measuring points, and carefully pull the HSS panel.
 When cutting HSS panels, avoid gas (torch) cutting if possible.
Instead, use a saw to avoid weakening surrounding areas due
to heat. If gas (torch) cutting is unavoidable, allow a minimum
margin of 50 mm (1.97 in).
 When welding HSS panels, use spot welding whenever possi- ble in order to minimize weakening surrounding areas due to
heat.
If spot welding is impossible, use MIG. welding. Do not use
gas (torch) for welding because it is inferior in welding
strength.
 Spot welding on HSS panels is harder than that of an ordinary steel panel.
Therefore, when cutting spot welds on a HSS panel, use a low
speed high torque drill (1,000 to 1,200 rpm) to increase drill bit
durability and facilitate the operation.
PIIA0115E
PIIA0117E
PIIA0144E
PIIA0145E
Revision: 2010 May2011 QX56