20-NA-079 Service Bulletin/Repair Instructions

Service Bulletin
Bulletin No.:
20-NA-079
Date:
May, 2022
TECHNICAL

Subject:
Front Brake Squeal Noise Heard During Light Brake Pedal Application
Brand:
Model:
Buick

Chevrolet
Model Year:

from
to
Encore GX
2020
2021
Trailblazer

(VIN M)
2021
2021
Date Breakpoint

from
to
SOP
March 20, 2020
Engine:
Transmission:
All
All
Involved Region or Country
United States, Canada, Except China
Condition
Some customers may comment on hearing a squeal noise originating from the front of the

vehicle during light brake pedal application.
Cause
The squeal noise can occur during light brake pedal application at low vehicle speed

when the brakes are first applied or lightly applied, such as exiting a parking lot.

Occasionally this noise may appear from the front, while in Reverse, after a period of nonuse such as overnight, or cold brakes and/or in high humidity conditions.

Note: Some brake noises are normal characteristics of all brake systems. These noises

cannot be avoided and may not indicate improper operation of the brake system. Refer to

Disc Brake System Description and Operation in the Service Manual.
Correction
For vehicles within the range of SOP to March 20, 2020, replace the front brake pads and

sensors, and apply grease following the steps in the Service Procedure below.

Note: For vehicles built after March 20, 2020, and before February 15, 2022, see Service

Bulletin # 22-NA-095.
Service Procedures

New Replacement Front Brake Disc Pads and

Sensors (if equipped) Service Procedure

Important: Only the Encore GX Models are equipped

with brake wear sensors. The Trailblazer Models are

NOT equipped with these sensors.

1. Remove the front brake disc pads and sensors (if

equipped). Refer to Front Disc Brake Pads

Replacement in the Service Manual.
6077243
Note: There are 4 Pad abutments per caliper.
Copyright 2022 General Motors LLC. All Rights Reserved.
Page 2
May, 2022
Bulletin No.: 20-NA-079
6077247
Note: The green area shown above designates the

required grease positions.
Bulletin No.: 20-NA-079
May, 2022
Page 3
6077250
Note: The above graphics are actual grease adding

examples.

2. Clean the pad spring abutment area on the caliper

and anti-rattle clip.

Note: The recommended grease volume is about 1.1 g

per caliper.

3. Apply Molykote M-77 Grease (GM P/N 19356408)

on caliper pad spring abutment and clip as shown

in the graphic above.

4. Install new front brake disc pads and sensors (if

equipped). Refer to Front Disc Brake Pads

Replacement in the Service Manual.

5. Verify brake noise has been eliminated.
Parts Information

Causal

Part
Description
Part

Number
Qty
X
PAD KIT, FRT

DISC BRK
42747910
1
42726383
1
19356408

(in Canada,

19356409)
As needed
N/A

N/A
FRT DISC BRK

PAD WEAR

SENSOR

(Encore GX Only)

MOLYKOTE

LUBRICANT,

MULTIPURPOSE

M-77 PASTE
Warranty Information

For vehicles repaired under the Bumper-to-Bumper

coverage (Canada Base Warranty coverage), use one

of the following appropriate Labor Operations.

Reference the Applicable Warranties section of

Investigate Vehicle History (IVH) for coverage

information.

Labor

Operation

2486218*
Description
Labor Time
Front Disc Brake Pads and

Sensor Replacement, Apply

Grease
1.0 hr
*This is a unique Labor Operation for bulletin use only.
Page 4
May, 2022
Bulletin No.: 20-NA-079
Version
5
Modified
Released July 16, 2020

January 19, 2022 – Added Trailblazer Model, added 2022 Model Year, updated Service

Procedures, Parts Information and Warranty Information.

March 23, 2022 – Added Date Breakpoint and a Second Note to the Correction.

May 13, 2022 – Added designations that only Encore GX Models are equipped with brake

wear sensors, Trailblazer models are Not equipped with sensors. Moved later Breakpoint

and repair to New Bulletin # 22–NA-095, corrected Model Years.

May 20, 2022 – Replaced incorrectly sized graphics and rearranged Notes above Service

Procedure step # 2.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these

technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper

service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a

job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your

vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the

information.
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TECHNICIAN

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