Service bulletin 04-004-20-3679

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10171845
Published by NHTSA	2020-02-29
Manufacturer's number	04-004-20-3679
Manufacturer's date	2020-02-20
NHTSA component	SERVICE BRAKES, HYDRAULIC

NHTSA's summary

Some vehicles may exhibit a click noise from the front brakes under one of the following conditions: When first moving the vehicle forward or reverse from a stop. When first applying the brakes while the vehicle is moving forward at slow speeds. Due to deteriorated grease between the brake pads and the shim, the front brake pads move upward/downward along with the brake rotors during brake application. When the vehicle moves or the brakes are applied the next time, the front brake pads move to the other side, which causes a click noise.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Brakes

Vehicles listed
MAZDA CX-9	2019, 2020

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
SA-029-26	2026-05-05. Service bulletin. This Service Alert supersedes the previously issued SA listed below: The changes are noted in Red. SA-011/24 02/12/24, 06/06/24, 07/29/24 DESCRIPTION Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. SCHEDULED MAINTENANCE Refer to the applicable Workshop Manual or Owner's Manual for vehicle -specific manufacturer scheduled maintenance. Workshop Manual - Refer to section 00-00 SCHEDULED MAINTENANCE. Owner's Manual - Refer to section 8 Maintenance and Care. b. Note: Please refer to the information below outlining the services not included in Mazda's Factory Scheduled Maintenance: IMPORTANT: Recommending fluid flushes when not necessary can lead to customer confusion and dissatisfaction. Fluid flushing for preventive maintenance purposes is strongly discouraged, unless otherwise specified in a published procedure (Owner’s Manual, Workshop Manual, Technical Service Bulletin, etc.).
SA-055-25	2025-12-05. Service bulletin. 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: Before following this Service Alert repair procedure, ensure published TSBs in MGSS have been completed per model year.
SA-016-24c	2024-11-04. Service bulletin. 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.
SA-016-24b	2024-09-04. Service bulletin. 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.
SA-016-24a	2024-07-05. Other. 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.
SA-016-24	2024-04-03. Service bulletin. 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.
SA-011-24	2024-03-06. Service bulletin. Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers.
SA-003-23a	2023-10-05. Service bulletin. 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.
SA-003/23	2023-02-02. Service bulletin. 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.
04-005-22	2023-01-05. Service bulletin. Front Brake Noise Symptom 1: Some vehicles may exhibit a click noise when first moving forward or reverse from a stop OR when first applying the brakes while moving forward at slow speeds. This is caused by deteriorated grease between the brake pads and the shim, the front brake pads move upward/downward along with the brake rotors during brake application. When the vehicle moves or the brakes are applied the next time, the front brake pads move to the other side, which causes a click noise. Front Brake Noise Symptom 2: Some vehicles may exhibit the brakes having an unusual noise or vibration when applying the brake. This is caused by rust on the brake disc plate’s surface. Rear Brake Noise Symptom 1: Some vehicles may exhibit grooves in rear brake disc plate(s). This concern is mostly found on new or low mileage vehicles, when the brakes are new. The grooves may be caused through abrasion from the accumulation of metal particles from the rear brake disc plates. The metal particles get caught between the brake pads and disc plates causing groove damage. To eliminate this concern, the disc plate surface honing process has been changed to reduce metal particle formation. Rear Brake Noise Symptom 2: Some vehicles equipped with an electric parking brake (EPB) may exhibit a grinding noise from the rear brakes when braking. This may be caused by the rear brake pads not having the capability to remove the rust from the rear brake discs. This is caused by rust on the brake disc plate’s surface. NOTE: The red rust accumulated on the discs is exposed to high temperatures during braking, and consequently the rust turns black. As the black rust is too hard to be removed by the brake pads, the rust progress is accelerated, resulting in the grinding noise.