200 INFINITI QX56 2009 Factory Service Manual

BR-24
< ON-VEHICLE REPAIR >
BRAKE TUBE AND HOSE
1. Check brake lines (tubes and hoses), and connections for fluid leaks, damage, twist, deformation, contact
with other parts, and loose connections. Replace any parts as necessary. Refer to BR-13, "
Hydraulic Cir-
cuit".
2. While depressing brake pedal under a force of 785 N (80 kg-f, 177 lb-f) with engine running for approxi- mately 5 seconds, check each part for fluid leaks.
Revision: December 20092009 QX56

BRAKE MASTER CYLINDERBR-25
< ON-VEHICLE REPAIR >
C
DE
G H
I
J
K L
M A
B
BR
N
O P
BRAKE MASTER CYLINDER
Removal and InstallationINFOID:0000000004042336
REMOVAL
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.
• Before removing brake master cylinder, depress the brake pedal 5-6 times with the key OFF to deplete vacuum in the booster.
1. Remove brake reservoir cap.
2. Disconnect harness connectors for fluid level sensor, front and rear pressure sensors.
3. Using suitable tool, disconnect brake tube from master cylinder assembly.
4. Remove master cylinder assembly nuts, and remove master cylinder assembly.
INSTALLATION
Installation is in the reverse order of removal.
• Refill brake fluid and bleed air. Refer to BR-17, "
Bleeding Brake System".
CAUTION:
• Refill with new brake fluid. Refer to MA-12, "
Fluids and Lubricants".
• Do not reuse drained brake fluid.
• Adjust brake pedal. Refer to BR-15, "
Inspection and Adjustment" .
1. Reservoir cap 2. Fluid level sensor 3. Grommet
4. Master cylinder assembly 5. Rear pressure sensor6. Front pressure sensor
7. Seal 8. Reservoir tankB. Brake fluid
R. Rubber grease
AWFIA0415GB
Revision: December 20092009 QX56

BR-26
< ON-VEHICLE REPAIR >
BRAKE BOOSTER
BRAKE BOOSTER
Removal and InstallationINFOID:0000000005890851
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 during
installation, dash panel may damage the threads.
• Attach the check valve in the correct direction.
REMOVAL
1. Remove air duct and resonator assembly. Refer to EM-25, "Removal and Installation".
2. Remove cowl top extension. Refer to EXT-18, "
Removal and Installation".
3. Remove master cylinder assembly from brake booster. Refer to BR-25, "
Removal and Installation".
4. Remove vacuum hose from brake booster. Refer to BR-28, "
Removal and Installation".
5. Disconnect active booster harness connector and delta stroke sensor harness connectors from brake booster.
6. Remove the instrument lower panel LH. Refer to IP-12, "
Exploded View".
7. Remove brake pedal to clevis attachment snap pin and clevis pin from inside the vehicle.
8. Remove brake booster to brake pedal assembly nuts.
9. Reposition the A/C line out of the way.
10. Remove brake booster and spacer block from dash panel.
INSPECTION AFTER REMOVAL
Output Rod Length Inspection
1. Reservoir tank 2. Master cylinder assembly3. Gasket
4. Brake pedal 5. Lock nut 6. Spacer block
7. Brake booster 8. Active booster harness connector 9. Delta stroke sensor
AWFIA0416GB
Revision: December 20092009 QX56

BRAKE BOOSTERBR-27
< ON-VEHICLE REPAIR >
C
DE
G H
I
J
K L
M A
B
BR
N
O P
1. Using a hand vacuum pump, apply a vacuum of – 66.7 kPa (– 500 mmHg, –19.69 inHg) to brake booster.
2. Check output rod length.
INSTALLATION
1. Loosen lock nut to adjust input r od length so that the length (B)
is set at the specified value.
2. After adjusting length (B), temporarily tighten lock nut and install brake booster and spacer block.
• Install the gaskets and spacer block between brake boosterand dash panel.
3. Connect brake pedal to clevis on the input rod.
4. Install brake booster to brake pedal assembly nuts and tighten to the specified torque.
5. Connect active booster harness connector and delta st roke sensor harness connectors to brake booster.
6. Connect vacuum hose to brake booster.
7. Install master cylinder assembly to brake booster. Refer to BR-25, "
Removal and Installation".
8. Adjust the height and play of brake pedal. Refer to BR-15, "
Inspection and Adjustment".
9. Tighten lock nut of input rod to specification.
10. Install the instrument lower panel LH. Refer to IP-12, "
Exploded View".
11. Secure A/C line into clips.
12. Install cowl top extension. Refer to EXT-18, "
Removal and Installation".
13. Install air duct and resonator assembly. Refer to EM-25, "
Removal and Installation".
14. Refill with new brake fluid and bleed air. Refer to BR-17, "
Bleeding Brake System".
Output rod length : Refer to
BR-46, "
Brake
Booster".
SBR208E
Input rod length (B) : Refer to BR-46, "Brake
Booster".
WFIA0382E
Revision: December 20092009 QX56

BR-28
< ON-VEHICLE REPAIR >
VACUUM LINES
VACUUM LINES
Removal and InstallationINFOID:0000000003772441
REMOVAL
1. Remove engine room cover.
2. Disconnect vacuum hose from hose clip.
3. Release clamps and disconnect vacuum hose.
4. Remove check valve from brake booster.
INSTALLATION
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.
1. Hose clip2. Clamp3. Vacuum hose
4. Check valve
LFIA0216E
SBR225B
Revision: December 20092009 QX56

FRONT DISC BRAKEBR-29
< ON-VEHICLE REPAIR >
C
DE
G H
I
J
K L
M A
B
BR
N
O P
FRONT DISC BRAKE
Exploded View of Brake PadsINFOID:0000000005856027
Removal and Installation of Brake PadsINFOID:0000000005856028
WARNING:
Clean dust on caliper and brake pad with a vacuum dust collector to minimize the hazard of air borne
particles or other materials.
CAUTION:
• While removing cylinder bod y, do not depress brake pedal because piston will pop out.
• It is not necessary to remove bolts on torque member and brake hose except for disassembly or replacement of caliper assembly. In this case, hang cylinder body with a wire so as not to stretch
brake hose.
• Do not damage piston boot.
• If any shim is subject to serious corrosion, replace it with a new one.
• Always replace shims and shim covers as a set when replacing brake pads.
• Keep rotor free from brake fluid.
• Burnish the brake pads and disc rotor mutually contacting surfaces, after refinishing or replacing rotors, after replacing pads, or if a so ft pedal occurs at very low mileage.
REMOVAL
1. Partially drain brake fluid. Refer to BR-17, "Drain and Refill".
2. Remove front wheel and tires using power tool.
3. Remove lower sliding pin bolts.
1. Inner shim cover 2. Inner shim3. Inner pad
4. Pad wear sensor 5. Pad retainer6. Outer pad
7. Outer shim 8. Outer shim cover Molykote AS-880N grease
AWFIA0675ZZ
Revision: December 20092009 QX56

BR-30
< ON-VEHICLE REPAIR >
FRONT DISC BRAKE
4. Hang cylinder body with a wire, and remove pads, pad retainers,shims, and shim covers from torque member.
CAUTION:
When removing the pad retainer from the torque member,
lift it in the direction indi cated by the arrow as shown so
that it does not deform.
INSTALLATION
1. Push piston in using suitable tool.
CAUTION:
In the case of replacing a pad with new one, ch eck the brake fluid level in the reservoir tank
because brake fluid returns to reservoir tank when pressing piston in.
NOTE:
Use a suitable tool to easily press piston.
2. Apply Molykote AS-880N grease or equivalent to between shim cover and shim. Install inner shim, inner shim cover to inner pad, and install outer shim, outer shim cover to outer pad.
3. Install pad retainers and pads to torque member. CAUTION:
• Securely assemble pad retainers so that they ar e not being lifted up from torque member.
• Both inner and outer pads have a pad return system on the pad retainer. Install pad return lever
securely to pad wear sensor.
4. Install cylinder body to torque member.
5. Install sliding pin bolts, and tighten it to the specified torque. Refer to BR-29, "
Removal and Installation of
Brake Pads".
6. Check front disc brake for drag and correct as necessary.
7. Install front wheel and tires. Refer to WT-41, "
Adjustment".
8. Check brake fluid level. Refer to BR-17, "
On Board Inspection".
Brake Burnishing ProcedureINFOID:0000000005856029
Burnish contact surfaces between disc rotors and pads according to following procedure after refinishing or
replacing rotors, after replacing pads, or if a soft pedal occurs at very low mileage.
CAUTION:
• Be careful of vehicle speed because the brake does not operate easily until pad and disc rotor are securely seated.
• 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 vehicle 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 through 3 until pad and disc rotor are securely seated.
SBR556E
Revision: December 20092009 QX56

FRONT DISC BRAKEBR-31
< ON-VEHICLE REPAIR >
C
DE
G H
I
J
K L
M A
B
BR
N
O P
Exploded View of Brake CaliperINFOID:0000000005856030
Removal and Installation of Brake Caliper and RotorINFOID:0000000005856031
WARNING:
Clean dust on caliper and brake pad with a vacuum dust collector to minimize the hazard of air borne
particles or other materials.
CAUTION:
• While removing cylinder bod y, do not depress brake pedal because piston will pop out.
• It is not necessary to remove bolts on torque member and brake hose except for disassembly or
replacement of caliper assembly. In this case, hang cylinder body with a wire so as not to stretch
brake hose.
• Do not damage piston boot.
• If any shim is subject to serious corrosion, replace it with a new one.
• Always replace shim and shim cover as a set when replacing brake pads.
• Keep rotor free from brake fluid.
• Burnish the brake pads and disc rotor mutually contacting surfaces, after refinishing or replacing rotors, after replacing pads, or if a so ft pedal occurs at very low mileage.
REMOVAL
1. Remove front wheel and tires using power tool.
2. Fasten disc rotor using wheel nut.
3. Drain brake fluid. Refer to CO-11, "
Changing Engine Coolant".
4. Remove union bolt, and then disconnect brake hose from caliper assembly.
1. Sliding pin bolt 2. Bleed valve 3. Cap
4. Union bolt 5. Brake hose 6. Copper washer
7. Torque member bolt 8. Sliding pin boot 9. Torque member
10. Sliding pin 11. Piston boot 12. Piston
13. Piston seal 14. Cylinder body B: Brake fluid
R: Rubber grease
AWFIA0683GB
Revision: December 20092009 QX56

BR-32
< ON-VEHICLE REPAIR >
FRONT DISC BRAKE
NOTE:
Discard the copper washers, do not reuse.
5. Remove torque member bolts, and remove brake caliper assembly.
CAUTION:
Do not drop brake pad.
6. Apply matching marks to disc rotor and wheel hub assembly as shown if the disc rotor is to be reused, then remove disc rotor.
CAUTION:
Put matching marks on wheel hub assembly and disc rotor
if the disc rotor is to be reused.
INSTALLATION
1. If reusing the disc rotor, use the matching marks to align discrotor on the wheel hub assembly as shown, then install disc
rotor using a wheel nut to hold it in place.
CAUTION:
Use matching marks on wheel hub assembly and disc rotor
if the disc rotor is to be reused.
2. Install brake caliper assembly, and tighten torque member bolts to the specified torque.
CAUTION:
Do not allow oil or any moisture on all contact surfaces
between steering knuckle and caliper assembly, bolts, and
washer.
SFIA2437E
SDIA2608E
SDIA2608E
SFIA2437E
Revision: December 20092009 QX56

FRONT DISC BRAKEBR-33
< ON-VEHICLE REPAIR >
C
DE
G H
I
J
K L
M A
B
BR
N
O P
3. Install brake hose to brake caliper assembly using new copper washers. Align the brake hose to the projection as shown and
tighten union bolts to the specified torque.
4. Refill with new brake fluid and bleed air. Refer to BR-17, "
Drain and Refill".
5. Check front disc brake for drag and correct as necessary.
6. Install front wheel and tires.
SFIA2431E
Revision: December 20092009 QX56