Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D

Subject: Wabco HP Air Dryer Turbo Cut-off Valve
Models Affected: Specific Model years 2019-2020 Freightliner
122SD, Cascadia, Western Star 4900, 5700, and 6900 manufactured March 6, 2018, through June 7, 2019, and equipped with a
WABCO HP air dryer.

General Information
Daimler Trucks North America LLC, on behalf of its Freightliner Trucks Division and wholly owned subsidiary
Western Star Truck Sales, is initiating Field Service Campaign SF591A-D to modify the vehicles mentioned
above.
On certain vehicles, the WABCO HP air dryer may experience signal line freeze-up, resulting in the inability
of the compressor to properly charge the air system.
A revised turbo cut-off valve assembly will be installed and the signal line cleared of moisture.
There are approximately 18,300 vehicles involved.
Additional Repairs
Dealers must complete all outstanding field service campaigns prior to the sale or delivery of a vehicle. A
Dealer will be liable for any progressive damage that results from its failure to complete campaigns before sale
or delivery of a vehicle.
Owners may be liable for any progressive damage that results from failure to complete campaigns within a
reasonable time after receiving notification.
Please contact Warranty Campaigns for consideration of additional charges prior to performing the repair.

Work Instructions
Please refer to the attached work instructions. Prior to performing the campaign, check the vehicle for a
completion sticker (Form WAR261).

Replacement Parts
Replacement parts are now available and can be obtained by ordering the part number(s) listed below from
your facing Parts Distribution Center.
If our records show your dealership has ordered any vehicle(s) involved in campaign SF591, a list of the
customers and vehicle identification numbers will be available on DTNAConnect. Please refer to this list when
ordering parts for this campaign.
Table 1 - Replacement Parts for SF591
Campaign Number

Part Number

Part Description

Qty. per Kit

SF591A-D

WAB 432 480 005 2
WAR261

KIT-SERVICE,VALVE,TCO,WABCO HP
BLANK COMPLETION STICKER

1 ea

Table 1

Removed Parts
U.S. and Canadian Dealers, please follow Warranty Failed Parts Tracking shipping instructions for the
disposition of all removed parts. Export distributors, please destroy removed parts unless otherwise advised.

Page 1

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D

Labor Allowance
Table 2 - Labor Allowance
Campaign
Number

Procedure

Time Allowed
(hours)

SRT Code

Corrective Action

SF591A, C

Remove and replace the WABCO HP air dryer
turbo cut-off valve

1.2

996-F054A

12-Repair Recall/Campaign

SF591B, D

Remove and replace the WABCO HP air dryer
turbo cut-off valve

2.0

996-F054B

12-Repair Recall/Campaign

Table 2

IMPORTANT: When the campaign has been completed, locate the base completion label in the appropriate location on the vehicle, and attach the gray completion sticker provided in the field service kit (Form WAR261). If
the vehicle does not have a base completion label, clean a spot on the appropriate location of the vehicle and
first attach the base completion label (Form WAR259). If a field service kit is not required or there is no completion sticker in the kit, write the campaign number on a blank sticker and attach it to the base completion label.

Claims for Credit
You will be reimbursed for your parts, labor, and handling (landed cost for Export Distributors) by submitting
your claim through the Warranty system within 30 days of completing this campaign. Please reference the
following information in OWL:
• Claim type is Field Service Campaign.
• In the Campaign field, enter the campaign number and appropriate group (SF591-A, SF591-B, etc.).
• In the Primary Failed Part field, enter 25-SF591-000.
• In the Parts section, enter the appropriate kit number(s) as shown in the Replacement Parts Table.
• In the Labor section, enter the appropriate SRT from the Labor Allowance Table. Administrative time will
be included automatically as SRT 939-6010A for 0.4 hours for RVs or 0.3 hours for all other vehicles.
• The VMRS Component Code is F99-999-005 and the Cause Code is A1 - Campaign.
• This Field Service Campaign will terminate on September 30, 2020. Dealers will be notified of any
changes to the termination date via Important Campaign Information Letter posted on DTNAConnect.com.
IMPORTANT: OWL must be viewed prior to beginning work to ensure the vehicle is involved and the campaign
hasAll
not
previously
been
completed.
Also,
a completion
sticker30
before
work. date of the
claims
must be
submitted
within
30 check
days offorthe
repair and within
days beginning
of the termination
campaign. U.S. and Canadian Dealers: All excess inventory to be returned to the PDC following the conclusion
of the campaign must be returned in resaleable condition to the Memphis PDC within 90 days from the
termination date. Please submit a PAR to request return to the Memphis PDC. (Canadian dealers should return
the kits to their facing PDC.). Export Distributors: Excess inventory is not returnable.
For questions, U.S. and Canadian dealers, contact the Warranty Campaigns Department via Web inquiry at
DTNAConnect.com / WSC, or the Customer Assistance Center at (800) 385-4357, after normal business hours,
if you have any questions or need additional information. Export distributors submit a Web inquiry or contact
your International Service Manager.

Page 2

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D

Copy of Notice to Owners
Subject: Wabco HP Air Dryer Turbo Cut-off Valve
Daimler Trucks North America LLC (DTNA), on behalf of its Freightliner Trucks Division and wholly owned
subsidiary Western Star Truck Sales, is initiating Field Service Campaign SF591A-D to modify specific Model
years 2019-2020 Freightliner 122SD, Cascadia, Western Star 4900, 5700, and 6900 manufactured March
6, 2018, through June 7, 2019, and equipped with a Wabco HP air dryer.
On certain vehicles, the WABCO HP air dryer may experience signal line freeze-up, resulting in the inability
of the compressor to properly charge the air system.
A revised turbo cut-off valve assembly will be installed and the signal line cleared of moisture.
Please contact an authorized Daimler Trucks North America dealer to arrange to have the campaign performed
and to ensure that parts are available at the dealership. To locate an authorized dealer, go to
www.Daimler-TrucksNorthAmerica.com. On the menu tab, select “Contact,” scroll down to “Find a Dealer,” and
select the appropriate brand. The campaign will take approximately one to two hours depending on the repair,
and will be performed at no charge to you.
This Field Service Campaign will terminate on October 31, 2020. Please make sure the campaign is
completed prior to this date. Work completed after this date will be done at the customer’s expense.
As stated in the terms of your express limited warranty, Daimler Trucks North America LLC will not pay for any
damage caused by failure to properly maintain your vehicle. Daimler Trucks North America LLC considers the
work necessary under this campaign to be proper maintenance and will, therefore, not pay for any damage to
your vehicle caused by your failure to have the repairs that are the subject of this campaign performed in a
reasonable time.
Contact the Warranty Campaigns Department at (800) 547-0712, from 7:00 a.m. to 4:00 p.m. Pacific Time,
Monday through Friday, e-mail address [email protected], or the Customer Assistance
Center at (800) 385-4357, after normal business hours, if you have any questions or need additional
information.

WARRANTY CAMPAIGNS DEPARTMENT
Enclosure

Page 3

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D

Work Instructions
Subject: Wabco HP Air Dryer Turbo Cut-off Valve
Models Affected: Specific Model years 2019-2020 Freightliner
122SD, Cascadia, Western Star 4900, 5700, and 6900 manufactured March 6, 2018, through June 7, 2019, and equipped with a
WABCO HP air dryer.

General Information
Some WABCO HP air dryers have experienced freeze-up issues. Follow the instructions below to replace the
cut-off valve. Part number TDA S432 470 921 2 is superseded to WAB432 480 005 2.

Replacement Procedure
1.

Inspect the base label (Form WAR259) for a campaign completion sticker for SF591 (Form WAR261). If a
sticker is present for campaign SF591, no work is needed. If there is no sticker, proceed with the steps
below.

2.

Park the vehicle on a level surface, shut down the engine, and apply the parking brake. Chock the tires.

3.

Drain the air from the system.

4.

Open the hood.

5.

Remove the bumper. For instructions see Group 31 of the applicable workshop manual.

6.

Disconnect the air compressor signal line from the air dryer.

7.

Disconnect the air compressor signal line from the air compressor side of the line.

8.

Using 50 psi (345 kPa) shop air, clean the signal line.

9.

Connect the signal line to the air dryer.

10.

Connect the signal line to the air compressor side of the line.

Page 4

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D
11.

Remove the snap ring that holds the turbo cut-off valve to the air dryer. See Fig. 1.

08/07/2019

f422695

Fig. 1, Snap Ring Holes

Page 5

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D

12.

Remove the plastic cover (orange and white in color) from the turbo cut-off valve. See Fig. 2 and Fig. 3.

1

08/07/2019

f422696

08/06/2019

f422697

1. Plastic Cover
Fig. 2, Removing the Plastic Cover

Page 6

Fig. 3, Plastic Cover Removed

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D

13.

Install the snap ring. See Fig. 4.

14.

Using 15 psi (103 kPa) shop air through the signal port of the air dryer, dislodge the turbo cut-off valve.
See Fig. 5.

08/07/2019

f422698

Fig. 4, Snap Ring Installed

Page 7

08/06/2019

f422699

Fig. 5, Applying Shop Air to Dislodge the Valve

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D
15.

Remove the snap ring again. See Fig. 6

16.

Remove and discard the turbo cut off valve. See Fig. 7 for an example of the valve.

08/06/2019

f422701

Fig. 7, Old Valve Removed

08/06/2019

f422700

Fig. 6, Snap Ring is Removed a Second Time

17.

Clean the turbo cut off valve bore, then inspect for any debris or damage; repair as needed.

18.

Lubricate the turbo cut off valve bore with the supplied grease.

Page 8

Daimler Trucks
North America LLC

Field Service Campaign

September 2019
SF591A-D
19.

Install the new turbo cut-off valve on the air dryer. See Fig. 8 for an example of the valve.

20.

Install the snap ring. See Fig. 9.

1
08/06/2019

f422702

2
Fig. 8, New Valve to be Installed

08/06/2019

1. New Valve

f422703

2. Snap Ring

Fig. 9, Snap Ring and New Valve Installed on the Air
Dryer

21.

Start the engine and build system pressure. Verify proper purge from the air dryer and system cut-out.

22.

Install the bumper. For instructions see Group 31 of the applicable workshop manual.

23.

Close the hood.

24.

Clean a spot on the base label (Form WAR259) and attach a campaign completion sticker for SF591
(Form WAR261) indicating this work has been completed.

Page 9