Bulletin No.: PIC6447B
Published date: 02/7/2025

Preliminary Information
PIC6447B Water Leak - Passenger Side Carpeting May Be Wet When
Using the Air Conditioning
Models
Brand:

Model: Model Years:

Chevrolet Corvette 2020 - 2024

VIN:
Engine: Transmissions:
from to
All
All All
All

Involved
Region or
Country

North America and Export Regions

Condition

Some customers may comment that the passenger side carpeting may be
damp or wet after using the air conditioning for some time.

Cause

This issue may be the result of water leaking from the HVAC case into the
passenger compartment, on the passenger side of the vehicle.

Correction:
If the passenger side carpeting is found to be wet after the air conditioning has been used,
the cause of this may actually be one of two different scenarios, both explained below. It
is imperative that BOTH conditions are examined when a car comes in for this concern. If a
vehicle exhibits both issues but the servicing technician only addresses one of them,
assuming that the vehicle has been fully repaired, he may have a comeback shortly
thereafter with the same complaint, even though the leak may be coming from a separate
area.
Condition #1 - The AC drain tube on this vehicle is located on the RH side of the center
console. It is located behind the carpeting that runs vertically up the side of the center
console assembly. The possibility exists that the AC evaporator drain tube may be
partially or fully disconnected from the body panel. Refer to Service Update #
N212327740 for further information on this condition.
Condition #2 - As previously mentioned, even if an issue was found with Condition #1, all
service technicians should also inspect / water test the vehicle for BOTH conditions listed
in this document. Another leak point that has been identified on this vehicle is a seam
between two body panels that is located just fore and several inches below where the AC
drain tube exits the vehicle. This area can be seen in the photo below.

A gap in the seam sealer along this location may also allow water from the AC drain system
to leak back inside the vehicle. To correctly repair this leak, a two-step approach is taken.
First, the technician must seal the seam between the two body panels INSIDE the vehicle
with seam sealer, available from any local body shop. Once that has been done,
technicians are to seal the OUTSIDE of the vehicle to prevent water from getting to this
area in the first place. To begin, first lift the car and remove the Floor Panel Tunnel Panel
Front Reinforcement (currently found on SI document ID 5358807.) This is the long,
narrow panel that covers the area historically referred to as the "transmission tunnel."
This will allow access to the "outside" of the panels where the water is leaking in at.

Once this panel has been removed, stand in the middle of the vehicle facing the front of
the car. If you look upwards and to the right, you will see the AC drain tube exiting the
center console area of the vehicle. Just below this AC drain tube, the technician is to
inspect for the presence of a black mastic patch that is covering the seam between these
two body panels. This patch can be seen in the computer image seen below.

The patch may or may not be present on the particular vehicle that is being serviced. It
was not added at the assembly plant until later built vehicles. If the patch is not present,
obtain a large piece of mastic from the parts department and apply it to the body so that
this seam area is completely covered. Use the image above as a guide for size and
placement. Be sure to wet out the patch correctly, using a roller, or a large socket. This
will ensure that the adhesive is completely sealed to the body panels and no water may
enter the vehicle in this location. If there already is a black mastic patch present in this
location, it should be removed and replaced with a new one. Install the new patch

following the same directions as listed above. This two-step repair will provide assurance
that no further water leaks will occur in this area again.

Warranty Information
The correction for this concern may be one of several repairs described above.
For vehicles repaired under warranty, please use the appropriate warranty
labor operation based on the actual cause and repair.

Version History
Version

3

Modified

10/12/2021 - Created on.
7/15/2022 - Updated to add model year 2023.
02/07/2025 - Updated to add model year 2024

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