IDX INFINITI QX4 2001 Factory Service Manual

SBR231C
2. Remove piston stopper while piston is pushed into cylinder.
3. Remove piston assemblies.
If it is difficult to remove secondary piston assembly, gradu-
ally apply compressed air through fluid outlet.
4. Draw out reservoir tank.
InspectionNBBR0021Check master cylinder inner wall for pin holes or scratches.
Replace if damaged.
SBR354C
AssemblyNBBR00221. Insert secondary piston assembly. Then insert primary piston
assembly.
IPay attention to direction of piston cups in figure at left.
Also, insert pistons squarely to avoid scratches on cylin-
der bore.
IPay attention to alignment of secondary piston slit with
valve stopper mounting hole of cylinder body.
SBR940A
2. Install stopper cap.
Before installing stopper cap, ensure that claws are bent
inward.
3. Push reservoir tank seals into cylinder body.
4. Push reservoir tank into cylinder body.
SBR435B
5. Install valve stopper while piston is pushed into cylinder.
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MASTER CYLINDER
Disassembly (Cont'd)
BR-17

SBR002A
SBR365AA
On-vehicle ServiceNBBR0024OPERATING CHECKNBBR0024S011. Depress brake pedal several times with engine off. After
exhausting vacuum, make sure there is no change in pedal
stroke.
2. Depress brake pedal, then start engine. If pedal goes down
slightly, operation is normal.
AIRTIGHT CHECKNBBR0024S021. Start engine, and stop it after one or two minutes. Depress
brake pedal several times slowly. Booster is airtight if pedal
stroke is less each time.
2. Depress brake pedal while engine is running, and stop engine
with pedal depressed. The pedal stroke should not change
after holding pedal down for30 seconds.
SBR368DA
RemovalNBBR0025CAUTION:
IBe 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.
IBe careful not to deform or bend brake pipes, during
removal of booster.
SBR208E
InspectionNBBR0026OUTPUT ROD LENGTH CHECKNBBR0026S011. Apply vacuum of þ66.7 kPa (þ500 mmHg, þ19.69 inHg) to
brake booster with a hand vacuum pump.
2. Add preload of 19.6 N (2.0 kg, 4.4 lb) to output rod.
3. Check output rod length.
Specified length:
10.275 - 10.525 mm (0.4045 - 0.4144 in)
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BRAKE BOOSTER
On-vehicle Service
BR-19

SBR382D
Vacuum HoseNBBR0028
SBR225B
Removal and InstallationNBBR0029CAUTION:
When installing vacuum hoses, pay attention to the following
points.
IDo not apply any oil or lubricants to vacuum hose and
check valve.
IInsert vacuum tube into vacuum hose as shown.
SBR498A
IInstall check valve, paying attention to its direction.
InspectionNBBR0030HOSES AND CONNECTORSNBBR0030S01Check vacuum lines, connections and check valve for airtightness,
improper attachment chafing and deterioration.
SBR943A
CHECK VALVENBBR0030S02Check vacuum with a vacuum pump.
Connect to booster side Vacuum should exist.
Connect to engine side Vacuum should not exist.
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VACUUM PIPING
Vacuum Hose
BR-21

SBR383D
1. Remove master cylinder reservoir cap.
2. Remove lower pin bolt.
SBR384D
3. Open cylinder body upward. Then remove pad retainers, and
inner and outer shims.
Standard pad thickness:
11.0 mm (0.433 in)
Pad wear limit:
2.0 mm (0.079 in)
Carefully monitor brake fluid level because brake fluid will
return to reservoir when pushing back piston.
RemovalNBBR0033WARNING:
Clean brake pads with a vacuum dust collector to minimize the
hazard of airborne particles or other materials.
CAUTION:
Suspend caliper assembly with wire so as not to stretch brake
hose.
SBR386D
Remove torque member fixing bolts and connecting bolt.
It is not necessary to remove connecting bolt except for dis-
assembly or replacement of caliper assembly. In this case,
suspend caliper assembly with wire so as not to stretch brake
hose.
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FRONT DISC BRAKE
Pad Replacement (Cont'd)
BR-23

SBR020B
ThicknessNBBR0035S0202Thickness variation (At least 8 positions):
Maximum 0.015 mm (0.0006 in)
If thickness variation exceeds the specification, turn rotor with on-
car brake lathe.
Rotor repair limit:
26.0 mm (1.024 in)
SBR574
AssemblyNBBR00361. Insert piston seal into groove on cylinder body.
2. With piston boot fitted to piston, insert piston boot into groove
on cylinder body and install piston.
3. Properly secure piston boot
SBR387D
InstallationNBBR0037CAUTION:
IRefill with new brake fluid ªDOT 3º.
INever reuse drained brake fluid.
1. Install caliper assembly.
2. Install brake hose to caliper securely.
3. Install all parts and secure all bolts.
4. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
Brake Burnishing ProcedureNBBR0086When experiencing soft brake pedal feel at very low mileage, or
after replacing the rotor, burnish the brake pad contact surfaces
according to the following procedures.
CAUTION:
Only perform this procedure under safe road and traffic con-
ditions. Use extreme caution.
1. Drive the vehicle on a straight smooth road at 50 km/h (31
MPH).
2. Use medium brake pedal/foot effort to bring the vehicle to a
complete stop from 50 km/h (31 MPH). Adjust brake pedal/foot
pressure such that vehicle stopping time equals 3 to 5 sec-
onds.
3. To cool the brake system, drive the vehicle at 50 km/h (31
MPH) for 1 minute without stopping.
4. Repeat steps 1 to 3 10 times or more to complete the burnish-
ing procedure.
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FRONT DISC BRAKE
Inspection (Cont'd)
BR-25

SBR093A
b. Tighten the two bolts gradually.
SBR266CA
2. After removing shoe hold pin by rotating push retainer, remove
leading shoe then remove trailing shoe. Remove spring by
rotating shoes in direction arrow.
Be careful not to damage wheel cylinder piston boots.
3. Remove adjuster.
SBR267CA
4. Disconnect parking brake cable from toggle lever.
Be careful not to damage parking brake cable when separat-
ing it.
SBR093B
5. Remove retainer ring with a suitable tool. Then separate toggle
lever and brake shoe.
SBR816B
InspectionNBBR0040WHEEL CYLINDERNBBR0040S01ICheck wheel cylinder for leakage.
ICheck for wear, damage and loose conditions.
Replace if any such condition exists.
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REAR DRUM BRAKE
Removal (Cont'd)
BR-27

SBR217B
3. Shorten adjuster by rotating it.
IPay attention to direction of adjuster.
Wheel Screw Depression
Left Left-hand thread Yes
Right Right-hand thread No
SBR279B
4. Connect parking brake cable to toggle lever.
5. Install all parts.
Be careful not to damage wheel cylinder piston boots.
6. Check all parts are installed properly.
Pay attention to direction of adjuster assembly.
7. Install brake drum.
8. When installing new wheel cylinder or overhauling wheel
cylinder, bleed air. Refer to ªBleeding Brake Systemº, BR-8.
9. Adjust parking brake. Refer to ªAdjustmentº, ªPARKING
BRAKE CONTROLº, BR-31.
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REAR DRUM BRAKE
Installation (Cont'd)
BR-29

SBR042D
AdjustmentNBBR00471. Adjust clearance between shoe and drum as follows:
a. Release parking brake lever and loosen adjusting nut.
b. Depress brake pedal fully at least 10 times with engine run-
ning.
2. Pull control lever4-5notches. Then adjust control lever by
turning adjusting nut.
SBR073D
3. Pull control lever with specified amount of force. Check lever
stroke and ensure smooth operation.
Number of notches:6-8
4. Bend warning lamp switchplate to ensure:
IWarning lamp comes on when lever is lifted ªAº notches.
IWarning lamp goes out when lever is fully released.
Number of ªAº notches: 1 or less
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PARKING BRAKE CONTROL
Adjustment
BR-31

System ComponentsNBBR0090
SBR447EB
SBR124B
System DescriptionNBBR0091SENSORNBBR0091S01The sensor unit consists of a gear-shaped sensor rotor and a sen-
sor element. The element contains a bar magnet around which a
coil is wound. The front sensors are installed on the front spindles
and the rear sensors are installed on the rear spindles. As the
wheel rotates, the sensor generates a sine-wave pattern. The fre-
quency and voltage increase(s) as the rotating speed increases.
SBR668E
CONTROL UNIT (BUILT-IN ABS ACTUATOR AND
ELECTRIC UNIT)
NBBR0091S02The control unit computes the wheel rotating speed by the signal
current sent from the sensor. Then it supplies a DC current to the
actuator solenoid valve. It also controls ON-OFF operation of the
valve relay and motor relay. If any electrical malfunction should be
detected in the system, the control unit causes the warning lamp
to light up. In this condition, the ABS will be deactivated by the
control unit, and the vehicle's brake system reverts to normal
operation. (For control unit layout, refer to ABS ACTUATOR AND
ELECTRIC UNIT, BR-33.)
SBR482E
ABS ACTUATOR AND ELECTRIC UNITNBBR0091S03The ABS actuator and electric unit contains:
IAn electric motor and pump
ITwo relays
ISix solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
IABS control unit
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DESCRIPTIONABS
System Components
BR-33

Component Parts and Harness Connector
Location
NBBR0092
SBR669E
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DESCRIPTIONABS
Component Parts and Harness Connector Location
BR-35