24-NA-221 Service Bulletin/Repair Instructions

Bulletin No.: 24-NA-221
Service Bulletin
Date: November, 2025
TECHNICAL

Subject:
Brand:
Chevrolet
Brake Squeal or Squeak Noise Intermittently on Initial Brake Applies

(Maintenance Reminder)

Model:
Corvette
Model Year:
VIN:
from
to
from
to
2025
2026
—
—
Engine:
Transmission:
All
All
Involved Region or Country
North America, Europe, Middle East, Israel, Palestine, Thailand, Japan, Australia/New

Zealand
Condition
Some customers may comment on a squeal, or squeak noise from the brakes. This

condition normally only occurs on initial brake applications after the vehicle has sat for an

extended time. The condition occurs typically under light braking at speeds under 16

km/h (10 mph). After 1-6 brake applies, or after braking at higher speeds, the noise no

longer occurs. This condition may occur more often in high humidity conditions.
Cause
Metal on metal contact causes the noise. The lubrication naturally wears away over time

with use, car washes, and environmental conditions.
Correction
Apply a coat of copper paste to completely cover the pad backing plate abutments on

each end. This maintenance item is not covered under warranty and is the financial

responsibility of the customer, as described in the Corvette owner's manual in the Vehicle

Care section, sub-section Brakes.
Service Procedure

Important: Service agents must comply with all International, Federal, State, Provincial, and/or Local laws

applicable to the activities it performs under this bulletin, including but not limited to handling, deploying,

preparing, classifying, packaging, marking, labeling, and shipping dangerous goods. In the event of a

conflict between the procedures set forth in this bulletin and the laws that apply to your dealership, you

must follow those applicable laws.

Important: The use of wheel cleaners or power washers directly pointed at the brake caliper may wash the copper

paste off of the brake pads. It may be necessary to apply the copper paste again if the lubricant is washed away.

The copper paste should be applied whenever the brake pads are removed or replaced.

To help reduce squeal, the brake pads are treated with an anti-squeal paste that may need to be reapplied periodically as part of normal vehicle maintenance. The anti-squeal paste will dissipate over time. Also, the use of wheel

cleaners or power washers directly on the brake calipers may remove the anti-squeal paste from the brake pads. It

may be necessary to reapply the anti-squeal paste if it is removed during cleaning.

If brake squeal is excessive, the anti-squeal paste should be reapplied. The anti-squeal paste should always be

reapplied whenever the brake pads are removed or replaced.

Apply a coat of copper paste to completely cover the pad backing plate abutments on each end. The paste should

not extend onto the friction material. Follow the instructions listed below.
Copyright 2025 General Motors. All Rights Reserved.
Page 2
November, 2025
Bulletin No.: 24-NA-221
3326987
(1) Abutment Area
5926095
(1) Cleaned Abutment Area

(2) Correct Amount of Copper Paste

(3) Incorrect Amount of Copper Paste

1. Remove the front disc brake pads. Refer to Front Disc Brake Pads Replacement in SI.

Note: Do not attempt to remove brake pad wear sensors. Support the harness during repair as needed to not stress

the wiring.

2. Remove the rear disc brake pads. Refer to Rear Disc Brake Pads Replacement in SI.
Bulletin No.: 24-NA-221
November, 2025
Page 3
4337633
3. Using acrysol Kent Industries Part# P2005 or equivalent, wipe clean both ends of the abutment area on the front

and rear pads and calipers.

4. Apply enough paste to the abutment area to match the picture above. Up to 2 grams of paste per vehicle corner

may be needed for larger Corvette brake systems (1 packet per corner).

Note: Ensure that the ends of the brake pads have enough copper paste applied. If not, it could result in the noise

condition returning.
4364263
Page 4
November, 2025
Bulletin No.: 24-NA-221
4364283
5. Reinstall the disc brake pads. Refer to Front Disc Brake Pads Replacement in SI.
4337814
Important: DO NOT remove the silencers (1) on the pads.

Important: Always replace brake pads with Brembo GM OEM pads (2). Aftermarket pads could result in the braking

performance changing in many ways.

6. Reinstall the rear disc brake pads. Refer to Rear Disc Brake Pads Replacement in SI.
Bulletin No.: 24-NA-221
November, 2025
Page 5
Parts Information
6313566
Description
Part Number
Qty
Molykote Lubricant Antiseize Paste*
19303310

(in

Canada, 193

03311)
N/A
*We believe this source and their products to be reliable.

There may be additional manufacturers of such products/

materials. General Motors does not endorse or indicate

any preference for or assume any responsibility for the

products or material from this firm or for any such items

that may be available from other sources.

Version
3
Modified
Released October 07, 2024

Revised August 11, 2025 – Added the 2026 Model Year and Australia/New Zealand to

Involved Region or Country section.

Revised November 07, 2025 – Updated Involved Regions/Countries, added Cause

section, added Note after Step 1 and updated Step 4.
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.
WE SUPPORT VOLUNTARY

TECHNICIAN

CERTIFICATION

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