BULLETIN NOTES
This service alert supersedes the previously issued service alert(s) listed below. The changes are noted in Red.
Previous SAs:

Date(s) Issued:

SA-016/24

03/08/24 and 06/06/24

SA-003/23

01/11/23 and 09/15/23

SA-078/22

12/20/22

SA-019/20

01/29/20

APPLICABLE MODEL(S)/VINS:
2016-2021 CX-3
2020-2025 CX-30
2013-2025 CX-5
2023-2025 CX-50
2025 CX-70
2016-2023 CX-9
2024-2025 CX-90
2013-2025 Mazda3
2014-2021 Mazda6
2022-2023 MX-30
2016-2024 MX-5
DESCRIPTION
Some vehicles exhibit brake related concerns such as brake noise, brake judder or brake dragging. If you encounter a
customer complaint for any one of these symptoms, refer to the following information to understand why symptoms may
occur, and to better assist the customer in resolving their specific brake concern.
NOTE: Prior to following this Service Alert repair procedure, ensure published TSBs in MGSS have been completed per
model year.
Some suggested simple MGSS search terms to use are:

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Brake noise
Brake sticking
Brake drag
Brake vibration

REPAIR PROCEDURE
BEST PRACTICES FOR BRAKE INSPECTION / REPAIR:

Always follow best practices during brake inspection or repair:
• Do not use grinding wheels or air-powered tools.
• Do not use air-powered tools to install wheels. Using power tools to tighten wheel nuts may cause a repeat brake
failure.
• When installing the wheels and tires, tighten the wheel nuts using a torque wrench.
• When performing any brake inspection or repair, always inspect the brake pad thickness first.
• Brake pad thickness of 2mm is 0% and should be replaced.
• Brake rotors should be machined whenever brake pads are replaced.
• Before replacing brake rotors, always take measurements and verify if they are within the tolerance that allows for
machining.
• When performing a repair requiring refinishing or replacement of the brake pads, lightly sand (use grit #80) or
machine the brake rotors using an on-car or bench brake lathe to remove old pad material.
• Brake pad replacement procedure for every model includes locations that require grease for noise dampening. Be
sure to apply grease at specified grease points according to MGSS online.

WHEEL AND TIRE INSTALLATION:

• DO NOT use air-powered tools to install wheels. Using power tools to tighten wheel nuts may cause repeat brake
failure.
• When installing the wheels and tires, tighten the wheel nuts using a torque wrench. Wheel nut tightening torque
can be found on MGSS online (GENERAL PROCEDURES (BRAKE)).

Click the link below for the appropriate symptom and repair section:
• BRAKE NOISE
• BRAKE JUDDER OR VIBRATION
• BRAKE DRAGGING OR STICKING

BRAKE NOISE:

There are various types of brake noise and many different conditions that can cause noise. The frictional coefficient
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between brake pads and rotors varies depending on pad material, temperature, humidity, braking force, etc. During
braking, the brake pads are pressed with great force against the brake rotor. This generates friction to bring the vehicle
to a stop.
• If the brake pads are of a soft compound, a larger amount of brake dust will appear on the wheels and the pads
will wear more rapidly, but there will be less chance of brake noise.
• If the brake pads are of a hard compound (as used in high-performance applications), less brake dust will appear,
the pads will last longer, and braking performance will be improved. However, the drawback is that brake noise
can occur more easily than with softer compounds.
Finding a balanced compound with the qualities of both hard and soft compounds is difficult.
• If you encounter a customer complaint for brake noise, first determine which wheel the noise is located at and
repair the cause of the noise. After the repair is complete, explain to the customer that it is very difficult to
completely eliminate brake noise from any vehicle, and that the noise could return with increased time and
mileage.
Groan Or Squeak Noise:
• If the noise is a groan or squeak while the brakes are applied, refinish the brake pads (provided they have
adequate thickness) using sandpaper (grit #80) or replace the brake pads with new parts.
Brake Dragging Noise:
• If the noise is due to brake dragging, check the caliper and sliders to ensure they are not seized. Rebuild or
replace the caliper and sliders as necessary. Clean off rust from all machined surfaces.
Rattle Or Clunk Noise:
• If a rattle or clunk noise is present, replace the brake pad shims/mounting hardware or replace the pads after
inspecting the fit of all parts and determining the cause of the excessive clearance. Clean off rust from all
machined surfaces.
When performing a repair requiring refinishing or replacement of the brake pads, lightly sand (use grit #80) or machine
the brake rotors using an on-car or bench brake lathe to remove old pad material.
NOTE:
• Do not use grinding wheels or air power tools.
• In most cases, brake rotor replacement is not necessary to remedy a brake noise condition, machine the rotors
using an on-car or bench brake lathe.
• Refer to MGSS online service information for lateral run-out, minimum rotor, and minimum pad thickness
specifications for the subject vehicle.
• Apply locally sourced CRC Disc Brake Quiet to the pad backing plates before each of the above repairs and
during brake replacement due to wear to reduce the occurrence of noise. The pad replacement procedure for
every model includes locations that require grease for dampening noises. These grease points are NOT for
lubrication. Use the CRC product in these locations. The image below is an example; the location will vary by
brake design and will be shown in MGSS for the model you are working on.
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BRAKE JUDDER OR VIBRATION:

Brake judder (or warping) is caused by uneven thickness (run-out) of the brake rotor. During braking, the clearance
between the pads and rotor becomes wider and narrower. This causes force onto the pads and may create a vibration.
Vibration is transferred through the brake hydraulic system and/or suspension and can be felt by the customer through
the brake pedal, vehicle floor and/or steering wheel. Even micron-size unevenness may cause brake judder. Brake
judder is more noticeable when slowing from a higher speed.
In most cases when brake judder is diagnosed, the rotors can be machined using an on-car or bench brake lathe and the
pads can be refinished using sandpaper to restore braking performance.
It is not necessary to replace the rotors and pads unless:
• Excessive unevenness (run-out) of the rotors is present that cannot be remedied by resurfacing without exceeding
the minimum thickness of the rotor.
• Excessive heat damage to the rotor (may include heat cracking).
• Excessive heat damage to the pads.
When you encounter a customer complaint about a brake judder, discuss the customer’s driving and vehicle storage
habits. Identify which wheel is causing the judder and visually inspect the rotors and pads to identify the cause.
NOTE: Refer to MGSS online service information for lateral run-out, minimum rotor, and minimum pad thickness
specifications for the subject vehicle.
Rust:
• If rust on the rotors and/or brake pads is identified as the cause of the unevenness, measure the lateral run-out
and machine the rotors using an on-car or bench brake lathe; refinish the pads with sandpaper (grit #80).
• If machining the rotors does not correct the brake judder, replace the rotors.
Excessive Heat Damage:
• If the rotors have excessive heat damage or cracking, replace them.
NOTE: Signs of rotor heat damage include blue spots or hard spots.
• If the rotors do not have excessive heat damage or cracking, measure the lateral run-out and machine the rotors
using an on-car or bench brake lathe. If machining the rotors does not correct the brake judder, replace the rotors.
• If the brake pads are heat damaged, replace them.
NOTE: Signs of brake pad heat damage include shiny surfaces or backing plate paint flaking.
• If the brake pads are not heat damaged, refinish them with sandpaper (grit #80).
Brake Pad Dragging:
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A dragging brake pad will cause excessive heat and may warp the rotors. This may result in brake judder. Perform the
inspection and repair for Excessive Heat Damage.
NOTE: During rotor replacement, ensure the hub is free from any foreign substances that may prevent the rotor from
fitting flush against the hub. A rotor that does not fit flush against the hub may experience a repeat brake judder.
BACK TO TOP

BRAKE DRAGGING OR STICKING:

This procedure will assist in finding the cause and appropriate repair for the brake dragging.
Inspection:
1. Check for DTCs, including pending DTCs.
NOTE: The source of the brake "drag" might not be a mechanical failure.
2. Safely raise the vehicle on a hoist.
3. Determine which wheel the brake dragging is coming from.
4. Remove the wheel, then rotate the brake rotor by hand to confirm the brake dragging.
5. Loosen, but do not remove the two (2) bolts securing the caliper to the bracket.
6. Remove the bottom bolt and rotate the caliper upwards.
7. Rotate the rotor by hand again and confirm if brake dragging is still present.
If brake dragging is still present, check for the following:
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Brake pads seized in the mounting support/hardware.
Contact between the brake rotor and other components.
A seized wheel bearing.
The brake booster push-rod is out of adjustment.
A seized or slow-to-return caliper piston.
A seized caliper slide pin(s).
The lateral run-out of the rotor exceeds specification.

Inspection Results & Repair:
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If seized brake pads are found, clean the mounting support/hardware and brake pads before reinstalling.
If contact between the brake rotor and other components is found, repair as necessary.
If a seized wheel bearing is found, replace it according to MGSS online service information.
If the brake booster push rod is out of adjustment, readjust it according to MGSS online service information.
If a problem is found with the caliper piston return, check for the possibility of water entry due to caliper piston boot
breakage or poor sealing, etc. Review the vehicle maintenance and repair history before deciding on whether to
rebuild or replace the caliper.
• If seized caliper slide pin(s) are found, remove the pins. Clean and lubricate the pins, then reinstall.
• If a brake rotor run-out problem is found, machine the rotors using an on-car or bench brake lathe and refinish the
brake pads using sandpaper (grit #80).
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PARTS INFORMATION
Locally Sourced Parts

CRC Disc Brake Quiet
CRC® Disc Brake Quiet, 4 Wt Oz

CRC® Disc Brake Quiet, 9 Wt Oz

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