21-NA-142 Service Bulletin/Repair Instructions

Bulletin No.:
Service Bulletin
Date:
21-NA-142

February, 2023
TECHNICAL

Subject:
Front Brake Grind/Groan Noise After Sitting Overnight

This bulletin replaces PIT5805B. Please discard PIT5805B.
Brand:
Model:
Buick
Enclave
Cadillac

Chevrolet

GMC
Model Year:

from
VIN and DATE Breakpoints:
to
from
to
2020
5GAERBKW8LJ296460
5GAERBKW3PJ183456
SOP
1GYKNAR42PZ158345
2021
SOP
1GYKPCRS1PZ157966
XT5

XT6

Blazer
2023
Traverse
2020
1GNERKKW5LJ296020
1GNERGKW1PJ183457
Acadia
2021
SOP
1GKKNRL49PZ161180
Engine:
Transmission:
All
All
North America, Russia, Middle East, Palestine, Japan, South Korea, Bolivia, Ecuador,

Chile, Colombia, Peru, GM Korea, Uzbekistan.
Involved Region or Country

Additional Options (RPOs)

Condition
Some customers may comment on hearing a brake noise on the first few stops. They may

describe it as a grind/groan sound, and it may feel like ABS is active, but it is not.
Cause
The cause of the condition may be the front disc brake pad material.
Correction
Verify the condition is present and verify the pad number stamp on the top edge of

the pad.

If you see GM9130 or GM9140 For Non-LSY applications ONLY

1. Replace the front disc brake pads with the parts listed below, refer to Front Disc

Brake Pads Replacement in the Service Manual

2. Scuff the rotors.

3. Perform the Brake Pad and Rotor Burnishing procedure. Refer to Brake Pad and

Rotor Burnishing in the Service Manual Complete a minimum of 20 stop events.

Procedure for LSY vehicles is still under development.
Parts Information

Causal

Part
Description
Part

Number
Qty
X
Pad Kit-Frt

Disc Brk
85619135
1
Copyright 2023 General Motors LLC. All Rights Reserved.
Page 2
February, 2023
Bulletin No.: 21-NA-142
Warranty Information

Repairs made for the specific concern within this

bulletin will be covered for a period of 24 months or

24,000 miles or 40,000 km, whichever occurs first.

Labor Operation
2486308*
Description
Base Labor Time
Front Disc Brake Pads Replacement and Scuff Both Front

Rotors
Enclave – 1.1 hr

Traverse – 1.1 hr

Blazer – 1.1 hr

Acadia – 1.2 hr

XT5 – 1.1 hr

XT6 – 1.6 hr
*This is a unique Labor Operation for Bulletin use only.
Version
9
Modified
Released June 21, 2021

Revised June 30, 2021 – Replaced LTG Labor Operation with Unique Bulletin Labor

Operation

Revised July 13, 2021 – Updated Parts Information with New Replacement Service Part

# 85520396.

Revised January 27, 2022 – Updated Breakpoints

Revised March 09, 2022 – Changed Blazer End Breakpoint from Date to VIN.

Revised April 14, 2022 – Added Note to Cause, Updated Correction, Increased Labor

Time and Replaced Labor Operation Number.

Revised August 23, 2022 – Added 2023 Model Year to All Models Except Colorado and

Canyon.

Revised December 14, 2022 – Updated Note in Cause Section.

Revised January 30, 2023— Removed Colorado and Canyon Models, Updated

Correction, Updated Part Number and Added Ending Breakpoints and changed

Labor Op#.
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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