Infiniti Q45 (FY33). Manual — part 72

NVH Troubleshooting Chart

Use the chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.

Reference page

BR-18,

22

BR-18,

22,

28

BR-26

BR-19,

23

—

—

BR-20,

25

—

—

—

BR-21,

25

—

Refer

to

PD

section.

Refer

to

PD

section.

Refer

to

F

A

and

RA

sections.

Refer

to

F

A

section.

Refer

to

F

A

section.

Refer

to

RA

section.

Refer

to

ST

section.

Possible cause and
SUSPECTED PARTS

Linings

or

pads

-

damaged

Linings

or

pads

-

uneven

wear

Return

spring

damaged

Shims

damaged

Rotor

or

drum

imbalance

Rotor

or

drum

damage

Rotor

or

drum

runout

Rotor

or

drum

deformation

Rotor

or

drum

deflection

Rotor

or

drum

rust

Rotor

thickness

variation

Drum

out

of

round

PROPELLER

SHAFT

DIFFERENTIAL

AXLE

AND

SUSPENSION

TIRES

ROAD

WHEEL

DRIVE

SHAFT

STEERING

Symptom

BRAKE

Noise

X

X

X

X

X

X

X

X

X

X

X

Shake

X

X

X

X

X

X

X

Shimmy, Judder

X

X

X

X

X

X

X

X

X

X

X

X

X: Applicable

GI

MA

EM

LC

EC

FE

AT

PD

FA

RA

ST

RS

BT

HA

EL

IDX

NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING

BR-5

SBR451D

Checking Brake Fluid Level

I

Check fluid level in reservoir tank. It should be between Max.
and Min. lines on reservoir tank.

I

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

I

When brake warning lamp comes on even when parking brake
lever is released, check brake system for leaks.

SBR389C

Checking Brake Line

CAUTION:

If leakage occurs around joints, retighten or, if necessary,
replace damaged parts.
1.

Check brake lines (tubes and hoses) for cracks, deterioration
or other damage. Replace any damaged parts.

2.

Check for oil leakage by fully depressing brake pedal while
engine is running.

SBR419C

Changing Brake Fluid

CAUTION:

I

Refill with new brake fluid “DOT 3”.

I

Always keep fluid level higher than minimum line on res-
ervoir tank.

I

Never reuse drained brake fluid.

I

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.

1.

Clean inside of reservoir tank, and refill with new brake fluid.

2.

Connect a vinyl tube to each air bleeder valve.

3.

Drain brake fluid from each air bleeder valve by depressing
brake pedal.

4.

Refill until brake fluid comes out of each air bleeder valve.
Use same procedure as in bleeding hydraulic system to refill
brake fluid. Refer to “Bleeding Brake System”, BR-7.

Brake Burnishing Procedure

Burnish the brake contact surfaces according to the following pro-
cedure after refinishing or replacing drums or rotors, after replac-
ing pads or linings, or if a soft pedal occurs at very low mileage.

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).

ON-VEHICLE SERVICE

BR-6

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.

SBR995

Bleeding Brake System

SBR419C

CAUTION:

I

Carefully monitor brake fluid level at master cylinder dur-
ing bleeding operation.

I

If master cylinder is suspected to have air inside, bleed air
from master cylinder first. Refer to “Installation”, “MAS-
TER CYLINDER”, BR-14.

I

Fill reservoir with new brake fluid “DOT 3”. Make sure it is
full at all times while bleeding air out of system.

I

Place a container under master cylinder to avoid spillage
of brake fluid.

I

Turn ignition switch OFF and disconnect ABS actuator
connector or battery cable.

I

Bleed air in the following order:
Right rear brake

,

Left rear brake

,

Right front brake

,

Left

front brake.

1.

Connect a transparent vinyl tube to air bleeder valve.

2.

Fully depress brake pedal several times.

3.

With brake pedal depressed, open air bleeder valve to release
air.

4.

Close air bleeder valve.

5.

Release brake pedal slowly.

6.

Repeat steps 2. through 5. until clear brake fluid comes out of
air bleeder valve.

7.

Tighten air bleeder valve.

: 7 - 9 N

⋅

m (0.7 - 0.9 kg-m, 61 - 78 in-lb)

GI

MA

EM

LC

EC

FE

AT

PD

FA

RA

ST

RS

BT

HA

EL

IDX

ON-VEHICLE SERVICE

Brake Burnishing Procedure (Cont’d)

BR-7

SBR612D

SBR992

Removal

CAUTION:

I

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.

I

All hoses must be free from excessive bending, twisting
and pulling.

1.

Connect a vinyl tube to air bleeder valve.

2.

Drain brake fluid from each air bleeder valve by depressing
brake pedal.

3.

Remove flare nut securing brake tube to hose, then withdraw
lock spring.

4.

Cover openings to prevent entrance of dirt whenever discon-
necting hydraulic line.

Inspection

Check brake lines (tubes and hoses) for cracks, deterioration or
other damage. Replace any damaged parts.

Installation

CAUTION:

I

Refill with new brake fluid “DOT 3”.

I

Never reuse drained brake fluid.

SBR686C

1.

Tighten all flare nuts and connecting bolts.

Flare nut:

: 15 - 17 N

⋅

m (1.5 - 1.7 kg-m, 11 - 12 ft-lb)

Connecting bolt:

: 17 - 20 N

⋅

m (1.7 - 2.0 kg-m, 12 - 14 ft-lb)

2.

Refill until new brake fluid comes out of each air bleeder valve.

3.

Bleed air. Refer to “Bleeding Brake System”, BR-7.

BRAKE HYDRAULIC LINE

BR-8