22-NA-026

Bulletin No.:
Service Bulletin
Date:
22-NA-026
February, 2024
INFORMATION
Subject:
Information on Brake Pulsation, Noise and/or Visible Pitting Condition to Brake Rotor
Surface
Brand:
Model:
Chevrolet
Corvette
Model Year:
VIN:
from
to
from
to
2020
2024
—
—
Engine:
Transmission:
All
All
Involved Region or Country
North America, Europe, Middle East, Japan, Australia/New Zealand
Additional Options (RPO’s)
Equipped with Performance Brakes (RPO J55 or J56)
Note: This condition may more commonly appear after the vehicle sits for an extended
period of time, especially in high humidity.
Condition
Copyright 2024 General Motors LLC. All Rights Reserved.
Some customers may comment on feeling a brake pulsation or hearing a noise when
applying the brakes. They may also comment on seeing a pitting condition with the brake
rotor's surface.
Following the information below will be helpful with reducing the surface corrosion.
Page 2
February, 2024
Bulletin No.: 22-NA-026
5969661
Cause
5969664
The cause of this condition may be corrosion pad spotting and surface grooving on the
brake rotor surface.
Correction
To help restore optimal braking performance and reduce noise, complete the Procedure
noted below.
Bulletin No.: 22-NA-026
February, 2024
Page 3
Procedure
If you encounter a vehicle with the above concern,
complete the following procedure:
Caution: Performing the brake burnish procedure on
JL9 base brake system can result in brake damage.
Caution: The new vehicle break-in period should be
completed before performing the brake burnishing
procedure or damage may occur to the powertrain/
engine. In the Owner Manual, refer to New Vehicle
Break-In.
Caution: Brake fade can occur during this burnish
procedure and can cause brake pedal travel and force
to increase. This could extend stopping distance until
the brakes are fully burnished.
Important: Perform this procedure only on dry
pavement, in a safe manner, and in compliance with all
local and state ordinances/laws regarding motor
vehicle operation.
Note: Completing the following procedure as
instructed will not damage the brakes. The brake pads
may smoke and produce an odor. The braking force
and pedal travel may increase. After the procedure, the
brake pads may appear white at the rotor contact.
5992650
1. The customer or technician should use the
Instrument Cluster’s DIC performance menu’s
friction bubble that calls out longitudinal G forces to
determine braking forces. Use the Friction Bubble
in the DIC display to determine the correct
deceleration rates. Apply the brakes 10 times
starting at 100 km/h (60 mph) to 50 km/h (30 mph)
while decelerating at 0.4g. This a medium brake
application. Drive for at least 0.5 km (0.3 mi)
between applying the brakes.
2. If further cleanup of the brake discs is needed,
repeat this procedure with 0.7g applications.
Tip: As with all high performance brake systems, some
amount of brake squeal is normal.
Version
3
Modified
Released January 28, 2022
Revised February 22, 2022 – Added the 2020 Model Year and corrected Step #1 in the
Procedure.
Revised February 13, 2024 – Added 2023-2024 Model Years and Additional Options
(RPOs) to table.
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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