Bulletin No.:

Service Bulletin

Date:

18-NA-383
March, 2023

TECHNICAL
Subject:
Brand:

Chevrolet

GMC

Water Found in Rear Interior of Cab, Water Leak at Rear Sliding Window
Model:

Model Year:
from

to

Silverado 1500
(New Model)

2019

2019

Silverado 1500
Silverado 2
500HD/3500HD

2020

2020

Sierra 1500
(New Model)

2019

2019

Sierra 1500
Sierra2500HD/3500HD

2020

2020

Copyright 2023 General Motors LLC. All Rights Reserved.

VIN:
from

to

SOP

FLINT: #LF262557
FORT WAYNE: #LZ285396
SILAO: #LG333724

Engine:Transmission:AllAll

Page 2March, 2023

Bulletin No.: 18-NA-383

Involved Region or Country

North America, Europe, Middle East, Iraq, Israel, Palestine, Argentina, Brazil, Bolivia,Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay, Taiwan, Thailand, Singapore,Philippines, Australia, New Zealand, Egypt, Africa, South Africa

Additional Options (RPOs)

WINDOW RR-FULL WIDTH, SLIDING, POWER (A48)

Condition

Customer may comment on finding water in the rear interior of the cab.

5203798

Cause

5201854

Bulletin No.: 18-NA-383

March, 2023

Page 35201855

Note: The cracks can be in the left and/or right side of the rear sliding window plastic
upper rail glass guide which is covered by the roof rear spoiler. Examples of a left (1),then right side (2) visual crack (with the spoiler removed) are shown in the graphics
above.
The cause of the condition may be cracking in the rear sliding window plastic upper rail
glass guide. The plastic upper rail glass guide may develop small fractures/cracking
which allows water to pass through on the glass side of the urethane that attaches to thevehicle body.
Important: When verifying this condition, ensure that the water leak path is due tocracks in the rear sliding window plastic upper rail glass guide, and NOT a leak in
the primary urethane seal, between the window and the body; or from the spoiler
attachments to the truck cab which are in the same area. Please indicate power
sliding rear window crack in warranty claim verbiage.
Correction

A leak in the primary urethane seal should be addressed by removing andresealing the window, using the standard service procedure from SI.
R & R the roof rear spoiler and apply seam sealer to the rear sliding window top
encapsulate, following the steps in the Service Procedure below.
Note: If the vehicle underwent this bulletin repair, was released to the customer
and later returned for the same concern, replace the rear sliding window assembly.
Refer to Rear Window Replacement in SI, AND ensure that during application of theurethane to the new window, that the urethane covers the complete length of the
top encapsulation of the window.

Page 4March, 2023

Bulletin No.: 18-NA-383

Service Procedure
Important: Service agents must comply with all
International, Federal, State, Provincial, and/orLocal laws applicable to the activities it performs
under this bulletin, including but not limited tohandling, 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 thelaws that apply to your dealership, you must follow
those applicable laws.

5201856

Important: Discard the 8 original central roof spoiler
nuts, they are NOT reusable fasteners.
1. Lower the rear portion of the headliner (1) andremove the roof rear spoiler (2). Refer to Roof Rear
Spoiler Replacement, in SI.

5201858

2.1. First using shop cloths and glass cleaner, or
suitable equivalent, clean all grime, debris
and water from the cavity.
5201857

2. Clean and inspect the full length of the cavity
above the body to window urethane:Bulletin No.: 18-NA-383

March, 2023

Page 55201859

2.2. Then, using compressed air, blow away any
excess moisture and allow the area to dry
thoroughly.

5201860

Important: Cut the applicator tip to a larger opening
and use care to avoid getting the sealer on the upper/
visible surfaces of the glass.
3. Apply a generous bead of M Ultrapro Autobody
Clear Sealant - 08302, or Wurth Euroseal Gel
Clear 18920104, or equivalent, across thecomplete length of the urethane/encapsulate.
Allow the sealer to flow to a uniform thickness
across the complete top of the window.

Page 6March, 2023

Bulletin No.: 18-NA-383

Parts Information*We believe these sources and their products to bereliable, and recommend using either product. Theremay be additional manufacturers of such products/materials. General Motors does not endorse, indicate
any preference for, or assume any responsibility for theproducts or material from this firm or for any such items
that may be available from other sources.
To obtain information for your local retail location,please call 3M at 1-888-364-3577.
Contact Wurth though website www.wurthusa.com, bye-mail at www.customer.service@wurthusa.com, or bycalling 1-800-987-8487.
In Canada, contact Wurth though their website atwww.wurth.ca/, by e-mail at info@wurth.ca, by calling
1-800-263-5002, or your local Wurth representative.
Causal
PartDescriptionPartNumberQuantity orMaterialAllowance**

NUT W/ WASHER
AND SEAL

11611049

83M Ultrapro
Autobody ClearSealant

08302

Wurth Euroseal
Gel Clear (5 oz/148 ml)*

18920104(892.0104 inCanada)

5201861

Note: The graphic above is a top view of the sliding
window, while standing in the bed of the truck.
Important: The 8 central roof spoiler nuts are NOT
reusable fasteners. The original fasteners must bediscarded and replaced.
4. Allow a short time for the sealer to develop a skim
coat, then reinstall the spoiler and headliner. Referto Roof Rear Spoiler Replacement, in SI.
5. Allow at least 24 hours before running the truck
through any car wash.

N/A$30.00**Material Allowance intended to cover cost of 1 full tube perrepair. Submit as “Net Item Miscellaneous”.

Warranty Information
For vehicles repaired under the Bumper-to-Bumper
coverage (Canada Base Warranty coverage), use thefollowing labor operation. Reference the Applicable
Warranties section of Investigate Vehicle History (IVH)
for coverage information.
Labor Operation

Description

Labor Time

2081088*

R & R Roof Rear Spoiler, Apply Seam Sealer to Rear Sliding
Window

1.9 hr*This is a unique Labor Operation for Bulletin use only.

Bulletin No.: 18-NA-383

March, 2023

Page 7Version13

Modified

Released January 03, 2019
Revised February 01, 2019 – Added Important to Correction to Verify Failure.
Revised March 22, 2019 – Added Breakpoint and Revised Correction Important.
Revised May 30, 2019 – Updated the Labor Time in Warranty Information.
Revised December 10, 2019 – Removed Breakpoint, Added 2020 Model Years, andUpdated Export Countries.
Revised January 08, 2020 – Updated the Parts Information Section and Increased theMaterial Allowance.
Revised February 17, 2020 – Updated Correction Section with Note as Remedy for
Second Repair Attempt.
Revised March 12, 2020 – Added Important Statements before steps #1 and #4 of theService Procedure.
Revised April 03, 2020 – Increased Material Allowance and Added Option of Additional
Sealer supplier
Revised July 14, 2020 – Added Non-reusable Nut Part Numbers to Parts Table.
Revised August 04, 2020 – Corrected Procedure Referenced in Note, within theCorrection.
Revised October 23, 2020 – Added VIN Breakpoints.
Revised March 07, 2023 — Replaced Kent Product information with 3M productinformation and added Important Statement.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform thesetechnicians 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 ajob properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that yourvehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from theinformation.

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