TECHNICAL SERVICE BULLETIN
DEPARTMENT OF COMPLIANCE

VEHICLE SAFETY AND RECALL MANAGEMENT
BUILDING 11
423 N MAIN ST
MIDDLEBURY, INDIANA 46540-9218

Technical Service Bulletin: 410-1371
Expiration Date: August 31, 2022

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Integrity

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Safety

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Quality

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Customer Service

8/2/2021

This Notice applies to your vehicle VIN listed above.
Dear Forest River Customer:
Forest River is alerting you to an issue involving certain 2021 – COLUMBUS - CMF390RL, CMF390RLW, CMF392MB
AND CMF392MBW fifth wheel travel trailer recreational vehicles. Please see the information below which describes the
issue and provides you with details on the steps you should take to have your vehicle repaired.
WHAT IS THE ISSUE?
Possible poor seal insulation at the return air portion and/or air duct or trunk line of the air conditioner.
OWNERS: WHAT SHOULD YOU DO?
Please contact your dealer and request a service appointment to schedule the free repair within one year of receiving this
notice. This TSB will expire on August 31, 2022 or at the end of the Forest River’s Manufacture Warranty. The vehicle
Owner is responsible for making arrangements to have the work completed. Please state you have been notified by
Forest River of the issue and provide the TSB number (located at the top of this page) to the dealership. It is also helpful
to give the dealership a copy of this letter when you take your vehicle in for the repair.
You may visit www.forestriverinc.com to search for dealer locations.
HOW LONG WILL THE REMEDY PROCESS TAKE?
The estimated time of repair is 2.50 hours. However, the dealership may need to keep your vehicle or schedule an
appointment with you for a later date to fit into their regular service schedule.
DEALERS: WHAT SHOULD YOU DO?
Dealer Service Procedures are locate on Dealer Connect. If more time than 2.50 hrs.is needed, please submit for prior
authorization.
MAY FOREST RIVER ASSIST YOU FURTHER?
EMAIL
CONTACT
PHONE
COLUMBUS CUSTOMER SERVICE
(574) 821-1487
[email protected]
Repair Codes:
Pictures are required for the remedy and/or inspection after installation.
Pictures of the remedy are a condition of payment in which must be provided with a claim against the repair code(s).
TSB
NUMBER
410-1371

REPAIR CODE

DESCRIPTION

TIME

SB-431-19-00-004078

PERFORM REMEDY PER INSTRUCTIONS

2.50 HRS.

WHAT IF YOU HAVE PREVIOUSLY PAID FOR REPAIRS TO YOUR VEHICLE FOR THIS PARTICULAR CONDITION?
If you have already paid for a repair that is within the scope of this service bulletin, you may be eligible for a refund of
previously paid repairs. Refunds will only be provided within the scope of this Technical Service Bulletin.
Please send the service invoice to the following address:
Columbus
Forest River, Inc.
Attn: WARRANTY MANAGER
105 14th Ave.
Middlebury, IN 46540

Sincerely,
Forest River, Inc.
Office of Corporate Compliance
Page 1 of 1

TECHNICAL SERVICE BULLETIN 410-1371 REMEDY INSTRUCTIONS
Make(s): COLUMBUS FIFTH WHEEL
Model(s): MANY, SEE BELOW
Model Year(s): 2021
Concern:
POSSIBLE POOR SEAL INSULATION AT
THE RETURN AIR PORTION AND/OR AIR
DUCT OR TRUNK LINE OF THE AIR
CONDITIONER.

Repair Code: SB-431-19-00-004078
Allotted Time: 2.50 HRS.
Inspection Code: N/A
Allotted Time: N/A
Photo(s) Required: YES
Prior Authorization Required: SEE NOTE
Part(s) Number: N/A
Part(s) Return: N/A

Disconnect the vehicles’ battery Positive and Negative, disconnect any House battery(s) Positive and
Negative, if equipped with a generator ensure it is off and lastly, ensure the vehicle is disconnected from
shore power. Block any tires/wheels to prevent the vehicle from rolling. Failure to do so may result in
electrocution, fire or other personal injury, property damage and/or death.
MODES: CMF390RL, CMF390RLW, CMF392MB AND CMF392MBW

NOTE: IF MORE TIME THAN 2.50 HRS. IS NEEDED, PLEASE SUBMIT FOR PRIOR AUTHORIZATION.
PHOTOS OF THE SEALED OFF REAR OF THE AC BEFORE AND AFTER REPAIR IS A CONDITION OF PAYMENT
STEP 1: REMOVE THE PANEL ON THE BACKSIDE OF THE AIR CONDITIONER, WHICH IS ACCESSIBLE FROM THE REAR TRUNK DOOR.
CHECK TO SEE IF A 1.5” FOAM PIECE IS BEHIND PANEL. THIS INSULATES AND ADDS STRENGTH TO THE PANEL TO PREVENT
DAMAGE FROM STOWED ITEMS. ALSO, CHECK THAT FOAM WAS ADDED TO THE FRONT PORTION OF THE AIR CONDITIONER
HOUSING;

FOAM

STEP 2: REMOVE THE FOAM TO ACCESS THE DIVIDER PANEL. ENSURE THAT THE DIVIDER PANEL IS SEALED ON ALL FOUR SIDES;
STEP 3: CHECK ALL THE WAY AROUND THE AIR CONDITIONER,
ALONG THE BOTTOM, TO BE SURE THAT IT’S SEALED TO
THE MOUNTING FRAME. SCREWS IN THE FRAME CAN
CAUSE THE AIR CONDITIONER TO BE LIFTED SLIGHTLY,
ALLOWING AIR TO PASS THROUGH;

STEP 4: VACUUM OUT ANY FOAM BEADS THAT ARE LEFT IN THE
COMPARTMENT, AS THEY TEND TO GET PULLED INTO THE REAR
FINS OF THE AIR CONDITIONER.
Page 1 of 4

TECHNICAL SERVICE BULLETIN 410-1371 REMEDY INSTRUCTIONS
Make(s): COLUMBUS FIFTH WHEEL
Model(s): MANY, SEE BELOW
Model Year(s): 2021
Concern:
POSSIBLE POOR SEAL INSULATION AT
THE RETURN AIR PORTION AND/OR AIR
DUCT OR TRUNK LINE OF THE AIR
CONDITIONER.

Repair Code: SB-431-19-00-004078
Allotted Time: 2.50 HRS.
Inspection Code: N/A
Allotted Time: N/A
Photo(s) Required: YES
Prior Authorization Required: SEE NOTE
Part(s) Number: N/A
Part(s) Return: N/A

STEP 5: SEAL BETWEEN THE REAR FRAME AND THE REAR WALL OF THE UNIT. ALSO, SEAL BETWEEN THE REAR FRAME AND THE
FLOOR OF THE UNIT;

SEAL BETWEEN REAR FRAME
AND REAR WALL OF TRAILER
SEAL BETWEEN REAR FRAME
AND FLOOR

STEP 6: TAKE OFF THE EXTERIOR GRILL AND MAKE SURE THE TOP OF THE AIR CONDITIONER IS SEALED OFF TO THE RETURN AIR
AREA. IF IT IS SEALED WITH SILVER FOIL TAPE, IT NEEDS TO BE RESEALED WITH A BLACK FOAM SEAL OR CAULKING;

SEAL 3 SIDES OF A/C

STEP 7: CHECK TO SEE IF AIR IS ESCAPING OUT OF THE DUCTING IN THE AREA SHOWN. THERE HAVE BEEN ISSUES WITH
BUCKLING AT THE TOP AND AIR LEAKING. IF AIR IS LEAKING, SEE STEP 8 TO RESEAL;

UN-TAPE AND LOOSEN SEAM

Page 2 of 4

TECHNICAL SERVICE BULLETIN 410-1371 REMEDY INSTRUCTIONS
Make(s): COLUMBUS FIFTH WHEEL
Model(s): MANY, SEE BELOW
Model Year(s): 2021
Concern:
POSSIBLE POOR SEAL INSULATION AT
THE RETURN AIR PORTION AND/OR AIR
DUCT OR TRUNK LINE OF THE AIR
CONDITIONER.

Repair Code: SB-431-19-00-004078
Allotted Time: 2.50 HRS.
Inspection Code: N/A
Allotted Time: N/A
Photo(s) Required: YES
Prior Authorization Required: SEE NOTE
Part(s) Number: N/A
Part(s) Return: N/A

STEP 8: TO RESEAL, PUSH THE BOTTOM OF THE DUCT UP TO REVEAL THE TOP SEAM. RUN 1/2” (MAX) SCREWS THROUGH THE
UPPER SEAM INTO THE PLYWOOD FLOOR. BE SURE TO USE SCREWS 1/2” OR LESS TO PREVENT GOING THROUGH THE
FLOOR. AFTER THE SEAM IS SECURED, RESEAL THE BOTTOM;

PUSH BOTTOM OF DUST UP TO
EXPOSE TOP SEAM, RUN ½” LONG
(MAX.) PAN HEAD SCREWS INTO
UPPER SEAM

STEP 9: ENSURE THAT THE FRONT OUTBOARD FOAM IS SEALED TO THE FRONT BLACK PANEL OF THE AIR CONDITIONER HOUSING;
STEP 10: MAKE SURE THE DAMPER VENTS IN THE STORAGE AREA ARE
SHUT. IN EXTREME HOT WEATHER, THEY CAN BE TAPED OFF
TO COMPLETELY SEAL THEM FROM AIR ESCAPING;
STEP 11: CHECK ANY OTHER VISIBLE DUCTING IN THE STORAGE AREA
BY FEELING FOR AIR LEAKING WHILE THE AIR CONDITIONER
IS RUNNING.

SEAL ALL 4 SIDES

Page 3 of 4

TECHNICAL SERVICE BULLETIN 410-1371 REMEDY INSTRUCTIONS
Make(s): COLUMBUS FIFTH WHEEL
Model(s): MANY, SEE BELOW
Model Year(s): 2021
Concern:
POSSIBLE POOR SEAL INSULATION AT
THE RETURN AIR PORTION AND/OR AIR
DUCT OR TRUNK LINE OF THE AIR
CONDITIONER.

Repair Code: SB-431-19-00-004078
Allotted Time: 2.50 HRS.
Inspection Code: N/A
Allotted Time: N/A
Photo(s) Required: YES
Prior Authorization Required: SEE NOTE
Part(s) Number: N/A
Part(s) Return: N/A

STEP 12: FROM UNDERNEATH THE UNIT, LOCATE THE OPENING DIRECTLY UNDER THE AIR CONDITIONER. CAREFULLY CUT OUT AND
REMOVE THE SCREEN WITHOUT DAMAGING AIR CONDITIONER OR DUCTING AROUND IT. THE IMAGE TO THE RIGHT HAS THE
SCREEN ALREADY REMOVED.

REMOVED SCREEN

STEP 13: GET AN AMP DRAW FROM THE BLOWER MOTOR TO SEE IF THE BLOWER IS BEING RESTRICTED. ANYTHING BELOW 2.8 AMPS
WOULD INDICATE THAT THE BLOWER MOTOR RPMS ARE LOW, INDICATING RESTRICTIONS TO AIRFLOW.

STEP 14: COVER THE AIR CONDITIONER AND TEMPERATURE SENSORS IN A FOAM INSULATION WRAP LIKE THE PICTURE BELOW.

Page 4 of 4