Bulletin No.: 10-05-23-001C
Date: Oct-2012

Subject:

Brake Induced Pulsation/Vibration Felt in Steering Wheel, Rumble Noise from Underbody During Downhill
Descent (Verify Condition and Replace Front Brake Pads)

Models:

2008 Chevrolet Silverado Light Duty (LD)
2008 GMC Sierra Light Duty (LD)
2nd-Design Only – w/ Pad Spreading Spring Clips (Refer to PIT4611 for Design Identification)
Equipped with Disc/Drum Brakes (RPO JF3) and Stabilitrak (RPO JL4)

2009-2013 Chevrolet Silverado Light Duty (LD)
2009-2013 GMC Sierra Light Duty (LD)
Equipped with Disc/Drum Brakes (RPO JF3 or JF7) and Stabilitrak (RPO JL4)
This bulletin is being revised to add the 2013 model year. Please discard Corporate Bulletin Number 10-05-23-001B (Section
05 – Brakes).

Condition
Some customers may comment on a pulsation or vibration mostly concentrated in the steering wheel during downhill descent as specifically described. This
condition will most often begin as an increasing rumbling noise coming from the underbody or the front of the vehicle. This condition is exhibited mostly in
mountainous regions.
Note: Use care to ensure the following diagnosis and repair are only attempted if the conditions and concern match those listed, and if the concern can be
duplicated under the same conditions.

This condition occurs ONLY under the following conditions:

•

When the vehicle is driven as follows:

•
•
•
•

On a downhill descent on a fairly steep grade (approximately 5% or greater).
On taller hills (roughly 1.5♦km [1♦mi] road length or greater), without sharp turns.
At speeds above 64♦km/h (40♦mph).
Using the brakes just enough to maintain the speed limit when moving downhill.

•

Typically, a rumbling noise will be heard first, building in intensity, followed by increasing pulsation, or vibration, felt in the steering wheel, then typically felt in
the floor panel.

•

The condition will be eliminated once the vehicle is driven on relatively flat ground, typically for 1.5-3♦km (1-2 mi).

Cause
This condition may be caused by interaction between the front brake lining material and the front brake rotors.

Correction
Important: DO NOT attempt any repairs on the vehicle until you verify the specific condition is present by following the steps below:
1.

Warm up the vehicle by driving approximately 8♦km (5♦mi).
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2.

Drive the vehicle in the lane closest to the side of the fairly steep grade (roughly 5♦percent or greater), taller hill (roughly 1.5♦km [1♦mi] road length or
greater), without sharp turns, and with a speed limit of 64♦km/h (40♦mph) or greater, with the side windows down.

3.

While in Drive, descending downhill, apply the brakes naturally, only as needed, to maintain the speed limit.

4.

Observe for noise, followed by pulsation/vibration. Observe where the noise, pulsation and/or vibration are most noticeable.

5.

Drive the vehicle on relatively flat ground for 1.5-3♦km (1-2♦mi) to verify that the condition goes away completely.

Note: If the Front Pad Kit listed is used to correct any condition other than the condition described in this bulletin, the vehicle could experience higher mileage
corrosion-induced brake pulsation.
If the condition described HAS NOT been verified, or if the condition observed IS NOT most noticeable through the steering wheel, the observed condition may
have a different cause, such as a tire/wheel or rear brake issue, etc. Refer to SI for any further related diagnostics.
If the condition described has been verified, and if the condition is most noticeable through the steering wheel, and if the condition was eliminated after driving
the vehicle on relatively flat ground, typically for 1.5-3♦km (1-2 mi), perform the following inspections and repairs.
Important:

•

It is critical to use the proper OEM brake rotors. Use of Non-OEM rotors may prevent the condition from being corrected long term.

•

If Non-OEM rotors are identified, these rotors are NOT covered under the GM New Vehicle Limited Warranty.

1.

Inspect the front brake rotors to ensure that they are OEM rotors.

•

Remove the brake rotor from the vehicle.

•

Inspect the back side of the rotor for the Bosch Logo. If the Bosch logo IS NOT present, replace with OEM GM rotors, P/N♦25819670.

2.

Inspect the front brake rotors for Assembled Lateral Runout (LRO) and thickness variation. Follow SI procedures.

3.

Inspect the front brake rotors for minimum thickness. Follow SI procedures.

4.

If the rotors are within specifications, DO NOT refinish or replace the rotors.

5.

If the rotors are out of specifications, refinish the rotors on a qualified lathe, or replace the rotors as appropriate. Follow SI procedures.

2

Note: To prevent a noise concern, follow the brake pad insulator preparation and seating instructions as referenced in Front Brake Pad Replacement
(1500) in SI.
6.

Install the specified front pad kit, GM♦P/N♦25910432. Follow SI procedures.

7.

Ensure that the condition has been eliminated under the same conditions.

Parts Information
Part Number

Description

25910432

Pad Kit-Frt Disc Brk

25819670

Rotor-Frt Brk

Warranty Information
For vehicles repaired under warranty, use:
Note: H9745 includes time for road testing and for removal of 1 rotor to inspect for OEM markings.
Labor
Operation

Description

Labor Time

H9745*

Pads, Disc Brake-Front – R&R
Or Replace & Diagnose

1.2♦hrs

Add

To Refinish Rotor - One

0.3♦hr

Add

To Refinish Rotor - Both

0.6♦hr

Add

To Replace Rotor - One

0.1♦hr

Add

To Replace Rotor - Both

0.3♦hr

*This is a unique labor operation for bulletin use only. It will not be
published in the Labor Time Guide.

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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