ITB00024F

Classification :
Reference:
Dat e:
BR00-005f
ITB00-024f
July 23, 2013
ALL INFINITI; BRAKE NOISE/JUDDER/PEDAL FEEL DIAGNOSIS AND REPAIR
This bulletin has been amended to include vehicles built up to the publication date.
No other changes were made. Please discard all previous versions of this bulletin.
APPLIED VEHICLES: All Infiniti
SERVICE INFORMATION
•
This bulletin is to assist you in responding to customer questions about brake operation, and provides
diagnostic and repair information for each item listed, if any should occur.
•
Most brake issues fall into the following categories:
a. Brake Noise: A squeak, squeal, clunk, or groan that occurs when the brakes are applied or released.
b. Brake Judder: A vibration that can be felt in the vehicle, steering wheel, or brake pedal when the
brakes are applied.
c. Pedal Feel: The effort needed to operate the brakes is too high or too low.
SERVICE PROCEDURE
1. Verify the condition by road testing the vehicle with the customer.
2. Determine the specific brake issue based on the description in the Service Information above.
3. Follow the appropriate repair procedure(s), listed on the following pages, for your specific issue.
Infiniti Bulletins are intended for use by qualified technicians, not 'do-it-yourselfers'. Qualified technicians are properly trained
individuals who have the equipment, tools, safety instruction, and know-how to do a job properly and safely. NOTE: If you believe
that a described condition may apply to a particular vehicle, DO NOT assume that it does. See your Infiniti dealer to determine if this
applies to your vehicle.
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BRAKE NOISE
• Brakes can make a range of noises when applied or released. Some noises are normal and no repair
action should be taken.
• Use the following descriptions to identify the specific type of brake noise and the appropriate repair:
Squeak noise when the brakes are cold:
• Usually occurs during the first few stops in the morning.
• This is a normal condition. No service action is necessary
Squeak noise with the brakes at normal operating temperatures:
• Refer to technical bulletins specific to the model of vehicle regarding this issue.
• If there are no bulletins for the car you are working on, install OE type pads using the information listed
under Brake Service on page 5 of this bulletin and the appropriate Service Manual procedures.
Notes about brake pads and brake noise:
Original Equipment (OE) brake pads are installed on all current Infiniti vehicles at the factory.
• The OE pads use a Non-asbestos Organic (NAO) compound. The NAO material provides state of the
art resistance to squeal noise.
• These pads are available as service parts and must be used if replacing brake pads under the terms of
the Infiniti new car warranty.
Loud continuous squeak/squeal noise:
• Occurs with or without braking.
• This is a normal brake function. It occurs when the brake pad wear indicators contact the rotor.
• It indicates the brake pads are worn out and need to be replaced. Install new brake pads using the
information listed under Brake Service on page 5 of this bulletin and the appropriate Service Manual
procedures.
Groan noise when slightly releasing the brakes after coming to a stop:
• This is sometimes called “creep groan”.
• It is a normal condition. No repair or service is necessary.
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Groan noise during stopping:
• Usually caused by glazing of the rotor’s surface as a result of heavy or frequent braking.
• Refer to technical bulletins specific to the model of vehicle regarding this issue.
• Replace the brake pads, then resurface the rotors and finish them with sand paper. Refer to Brake
Service on page 5 for additional detail.
Single clunk noise from front suspension when applying the brakes:
• The noise is a result of the brake pads shifting in the direction of rotor rotation when the brakes are
applied.
• Can be duplicated by lightly touching the brake pedal.
• If the brake pedal is pushed hard, the noise is less likely to occur.
• Make sure the brake pads and pad hardware (shims, springs, clips, etc) are installed correctly.
• Refer to ASIST for vehicle specific brake service information.
• Refer to Brake Service on page 5 for additional detail.
Multiple clunk noise and/or pedal pulsation that occurs only one time after the engine is started:
• This is a normal ABS Self Check noise. No service action is necessary.
• The vehicle’s ABS system performs a self check. On some models, this self check occurs with the first
application of the brakes after the engine is started. On other models, the self check occurs the first
time the vehicle reaches 5 mph after the engine is started.
Rear Brake Squeal:
• Usually due to an accumulation of brake dust and dirt between the pads/shoes and rotors or drums.
• Clean all dust and dirt from the brake shoes, backing plates and related components.
WARNING: Brake dust may be hazardous if inhaled. Refer to the Service Manual (ESM) for brake
dust precautions and use approved brake cleaning equipment.
• Refer to ASIST (Service Bulletins and ESM) for correct installation and lubrication of brake pads,
caliper parts, and hardware.
CAUTION: Do not get grease on the brake pad friction surface.
BRAKE JUDDER
•
Brake Judder is caused by rotor thickness variation and/or rotor run out.
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Rotor Thickness Variation: When the inner and
outer surface of the rotor are not flat and not
parallel, the brake pads will travel in and out as
they follow the low and high spots on the rotor
(see Figure 1).
Figure 1
Rotor Run Out: If the brake rotor is not true to
the hub center, the brake pads contact one point
on each side of the rotor with each wheel
rotation, even if the brakes are not applied. Over
time, this point contact will cause the rotor to
wear more in these areas and cause rotor
thickness variation (see Figure 2).
Figure 2
• This motion of the brake pads is transferred through the caliper pistons and is felt in the brake pedal as a
pulsation. In severe cases it can also cause a back and forth oscillation in the steering wheel.
Vehicle Storage:
• If the vehicle is not operated for periods of time, the area of the brake rotors not covered by the brake
pads will rust.
• The friction characteristics between the rusted and un-rusted areas of the rotor braking surface will be
different.
• This difference may cause brake judder at low and/or high mileage, even after the rust wears off.
Lug Nut Overtorque:
• Another contributor of brake judder is lug nut overtorque. This can occur if the lug nuts are over
tightened, especially with an air impact wrench.
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Brake Judder Repair
• Brake judder issues must be corrected by turning the rotors with a ProCut™ PFM series On-Car Brake
Lathe.
• Refer to ITB04-038 for additional information on using this lathe.
• If the rotors are replaced, make sure you index them to the axle hub to ensure minimum runout (see
Rotor Indexing on page 7).
PEDAL FEEL
•
Some customers may say that the brake pedal feels too high or low when applying the brakes.
•
This may indicate the brake system needs service or it may be the result of the customer comparing the
feel of the brakes in a new car with the feel of the brakes in a previous car.
•
Road test the vehicle with the customer. Compare brake operation to a “known good” vehicle, and
determine if brake service is necessary. If so, refer to the following service items:
a. Inspect the brake calipers and make sure they are correctly installed and sliding freely.
b. Inspect the front and rear brakes and make sure the brake pads and/or shoes are properly installed.
c. Bleed all air from the brake system.
d. Make sure the brake pedal stroke and free play are adjusted correctly. Refer to the appropriate section
of the ESM which covers brakes.
NOTE: Use Essential Tool J-46532 (Brake Pedal Height Tool) for brake pedal height check and
adjustment. This tool is available from TECH-MATE at 1-800-662-2001.
BRAKE SERVICE
To ensure a high quality brake service be sure to:
1. Finish rotors properly.
•
This is one of the most important aspects of preventing and eliminating brake noise.
•
Use the ProCut™ PFM series on-car brake lathe. It has been chosen as the approved tool for rotor
resurfacing (refer to ITB04-038 for additional information).
2. Correctly install pads and shims.
IMPORTANT: Correct installation and lubrication of brake pads and all caliper parts and hardware is
essential for proper brake operation and will help dampen noise-causing movement and vibrations.
• Refer to ASIST (Service Bulletins and ESM) for correct installation and lubrication of brake pads,
caliper parts, and hardware.
CAUTION: Do Not get grease on the brake pad friction surface.
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3. Perform the following post-installation checks.
• Confirm that brake pads fit snugly in the calipers. Replace worn components as necessary.
• Test drive after repairs and burnish the new brakes. This will influence brake performance, including
noise.
a. Drive the vehicle on a straight smooth road at about 30 mph (50 kph).
b. Use medium brake pedal/foot effort to bring the vehicle to a complete stop from about 30 mph
(50 kph). Adjust your pedal/foot pressure so that the vehicle stopping time is 3-5 seconds.
c. Cool the brake system by driving at about 30 mph (50 kph) for approximately one minute without
stopping.
d. Repeat steps 1, 2, and 3 ten times to complete the burnishing process.
4. Follow-up to ensure customer satisfaction, safety, and proper brake performance.
• Confirm the procedures described in steps 2 - 4 above have been strictly followed.
ROTOR INDEXING
When installing a new rotor, a rotor that has been surfaced off the car, or a rotor that has been removed for any
reason, use the following indexing procedure to ensure the minimum amount of rotor run-out.
1. Make sure the rotor is fully contacting the hub. Clean the rotor-to-hub surface if it is rusty.
NOTE: For cleaning the hub surface, specifically around the wheel studs, it is recommended to use the
Wheel Hub Cleaning Kit #J-42450-A, which can be ordered from Nissan TECH-MATE at 1-800-662-2001.
2. Install the rotor and all lug nuts. Tighten the lug nuts to 40 ft-lbs (for this indexing process only).
3. Place a reference mark on the rotor and hub.
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Dial Indicator
(Measure Runout)
4. Measure rotor run-out with a dial indicator. If
the run-out is above limit continue with step 5.
• For more detail of the run-out limit, refer to
the ESM.
Brake Rotor
TP030606b
Figure 3
5. Remove the lug nuts and shift the position of the rotor one lug clockwise, then reinstall the lug nuts and
torque to 40 ft-lbs (again, for this indexing process only).
• Repeat step 4 and 5 until the rotor is positioned with the least amount of runout.
6. After you find the position with the least amount of runout, if the runout is still more than the limit you’ll need
to turn (resurface) the new rotors using the ProCut™ PFM Series on-car brake lathe.
CLAIMS INFORMATION
Please reference the current Infiniti "Warranty Flat Rate Manual" and submit your claim(s) using the Operation
Code (Op Code) or combination of Op Codes that best describes the operations performed.
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