Western Star 4800 and 4900 Radiator Mounting,
Update—EPA10
Constellation
Heritage
4700 Models

> 4800 Models
> 4900 Models

20-18
Western Star
Service Bulletin

5900 Models
6900 Models

Description of Revisions:This bulletin replaces the version dated
June 2014. All parts tables are replaced.

General Information
Some EPA10 compliant Western Star 4800 and 4900 vehicles manufactured March 2010 and later, with specific
combinations of engine operating parameters, may have radiator failures resulting in a coolant leak due to a
crack in the coolant tube. See Fig. 1. Leaks in other places (at the end tank, header, fittings, or any place other
than the coolant tubes) do not apply for this bulletin. If leaks occur in the coolant tubes, Western Star recommends a radiator update to an isolated engine-mounted radiator. Isolated engine-mounted radiators were production installed in 4800 and 4900 models beginning in August, 2012. This procedure is to replace a standard
engine-mounted radiator with an isolated engine-mounted radiator.

05/31/2005

f500383

Fig. 1, Crack in Coolant Tube

IMPORTANT: Before scheduling a vehicle for this procedure, determine if the vehicle to be serviced
has a set forward (SF) or set back (SB) axle configuration, then refer to Table 1 under "Parts" for a
listing of the required parts tables for each configuration.

Radiator Replacement
1. Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.
2. Remove the hood or remove the straps and open the hood while supporting it. For instructions, see Group
88 in the Western Star Workshop Manual.
3. Remove the bumper. For instructions, refer to Group 31 of the Western Star Workshop Manual.
4. Drain the coolant from the radiator and engine block.
5. Remove the charge air cooler (CAC) plumbing at the turbocharger outlet and the CAC inlet, and at the CAC
outlet and the engine inlet. See Fig. 2 and Fig. 3.

Western Star Service Bulletin, September 2014

Page 1

Western Star 4800 and 4900 Radiator Mounting,
Update—EPA10

20-18
Western Star
Service Bulletin

Constellation
Heritage
4700 Models

4

3

2

> 4800 Models
> 4900 Models

5900 Models
6900 Models

1

1
3

2
6
5

6

2

10/16/2012

1.
2.
3.
4.

4

f200767

CAC Inlet
Hose
Tube
Hose

5. Turbocharger Outlet
Pipe
6. Clamp

10/16/2012

f200768

1. CAC Outlet
2. Clamp

Fig. 2, CAC Plumbing, Turbocharger-to-CAC

3. Hose
4. Engine Inlet

Fig. 3, CAC Plumbing, CAC-to-Engine Inlet

6. Remove the upper radiator hose. See Fig. 4 for DDC engines, or Fig. 18 for Cummins engines.
7. Disconnect the surge tank vent line. See Fig. 6.
8. Remove the grille from the radiator.
9. Remove the baffles and mounting brackets located on both sides of the grille. See Fig. 7.
10. Loosen the A/C condenser and move it out of the way as follows.
10.1

Remove the receiver-drier and upper condenser-line mounting nuts, then free the receiver-drier. See
Fig. 8.

10.2

Remove the radiator baffle from the right side of the radiator.

NOTE: The A/C lines run through the right-side baffle. The baffle must be moved with the
condenser.
10.3

Unbolt the A/C condenser from the CAC. See Fig. 9.

NOTE: Wrap the condenser in cardboard to protect it while it is moved.
10.4

Carefully move the condenser around and set it on the right front tire. Secure it as needed. See Fig.
10 .

11. Remove the three radiator strut rods and discard them.
12. Unbolt the city horn from the side radiator channel if applicable.
13. Remove the upper fan shroud. See Fig. 11.
14. Remove the fan. For instructions, refer to Group 20 of the Western Star Workshop Manual.
15. Disconnect the lower radiator hose assembly at the radiator. See Fig. 12 for DDC engines, or Fig. 18 for
Cummins engines.

Page 2

Western Star Service Bulletin, September 2014

Western Star 4800 and 4900 Radiator Mounting,
Update—EPA10
Constellation
Heritage
4700 Models

> 4800 Models
> 4900 Models

20-18
Western Star
Service Bulletin

5900 Models
6900 Models

1

2

3

4

1
2

1
10/16/2012

1. Radiator
2. Upper Radiator Hose
3. Clamp

f200771

4. Clamp Fastener
5. Lower Radiator Hose

1
6

Fig. 4, Upper Radiator Hose Installation, DDC Engine

1
4
1

11/07/2013

1.
2.
3.
4.
5.
6.

3 1

5

f200830

Clamp
Upper Radiator Hose
Hose, Lower Radiator, Radiator to Tube
Lower Radiator Tube
Fastener
Hose, Lower Radiator Tube-to-Engine

Fig. 5, Radiator Hose Installation, Cummins Engine

16. Disconnect the transmission cooler lines from the radiator. Cap and/or plug the fittings to prevent spills.
17. Unbolt the radiator from the lower mounts.
18. Using an appropriate lifting device, remove the radiator assembly from vehicle. See Fig. 13.
19. Remove the lower fan shroud from the radiator. See Fig. 11.
20. Remove the upper radiator baffle.
21. Remove the CAC from the radiator.
22. Remove the transmission cooler fittings and the upper vent line fitting.
23. Install the transmission cooler fittings and upper vent line fitting on the new radiator.
24. Install the CAC on the new radiator.
25. Install the upper radiator baffle.

Western Star Service Bulletin, September 2014

Page 3

Western Star 4800 and 4900 Radiator Mounting,
Update—EPA10

20-18
Western Star
Service Bulletin

Constellation
Heritage
4700 Models

> 4800 Models
> 4900 Models

5900 Models
6900 Models

3
2
1

10/16/2012

f200769

1. Clamp
2. Line

3. P-Clamp
Fig. 6, Surge Tank Vent Line

1

2

1

3

2
02/01/2013

f880915

1. Baffle (one on each side of the grille)
2. Bracket (one on each side of the grille)
3. Grille
Fig. 7, Grille Assembly

11/28/2012

f200773

1. Upper Condenser
Line Mounting Nuts

2. Receiver-Drier
Mounting Nuts

Fig. 8, Receiver-Drier Installation (typical)

26. Apply sealant (48-00094-141) to the threads of the fasteners, then install the fan. Tighten 30 lbf·ft (41 N·m).
27. Install the fan shroud on the new radiator. See Fig. 11.
28. Remove the lower radiator mounting brackets from the engine.

Page 4

Western Star Service Bulletin, September 2014

Western Star 4800 and 4900 Radiator Mounting,
Update—EPA10
Constellation
Heritage
4700 Models

> 4800 Models
> 4900 Models

20-18
Western Star
Service Bulletin

5900 Models
6900 Models

2

3
4

1
05/24/2012

f200757

1. A/C Condenser
2. Isolator

3. Washer
4. Nut
Fig. 9, A/C Condenser Installation

29. Install the new lower radiator mounting brackets. See Fig. 14. Tighten 191 to 234 lbf·ft (260 to 317 N·m).
30. Install the lower radiator isolators on the mounting brackets. See Fig. 15.
31. Using an appropriate lifting device, position the new radiator assembly in the vehicle. Install the mounting
nuts, but do not tighten them at this time. See Fig. 15.
32. Install the lower radiator hose.
33. Connect the transmission cooler lines.
34. Install the new upper radiator hose. See Fig. 4 for DDC engines or Fig. 18 for Cummins engines.

IMPORTANT: On DD13 engines, the left strut rod attaches to the top of the bracket on the radiator.
On DD15/16 engines, the left strut rod attaches to the bottom of the bracket on the radiator.
35. Install the new isolated radiator strut rods. See Fig. 16 for DDC engine installations, or Fig. 17 for Cummins
engine installations. Tighten the radiator strut rod fasteners at the radiator 55 to 65 lbf·ft (75 to 90 N·m), and
at the engine block 125 to 139 lbf·ft (171 to 188 N·m) for DDC engines, or 55 to 65 lbf·ft (75 to 90 N·m) for
Cummins engines.
36. Tighten the radiator mounting nuts 140 to 170 lbf·ft (190 to 230 N·m).
37. Install the A/C condenser as follows.
37.1

Move the condenser into position and secure it temporarily. See Fig. 9.

37.2

Position the receiver-drier and upper A/C line on their respective brackets and install the mounting
nuts. See Fig. 8. Tighten the nuts 14 to 16 lbf·ft (19 to 22 N·m).

Western Star Service Bulletin, September 2014

Page 5

Western Star 4800 and 4900 Radiator Mounting,
Update—EPA10

20-18
Western Star
Service Bulletin

Constellation
Heritage
4700 Models

> 4800 Models
> 4900 Models

5900 Models
6900 Models

1

2
2

3
4
5

05/24/2012

f200760

1. Bungee Cord

2. Condenser

Fig. 10, Securing the A/C Condenser

1

10/04/2012

f200756a

1. Lower Fan Shroud
2. Upper Fan Shroud
3. Push Fastener

4. Washer
5. Screw

Fig. 11, Fan Shroud Installation

37.3

Tighten the condenser mounting nuts 112 to 144 lbf·in (1266 to 1627 N·cm).

37.4

Install the grille mounting brackets and baffle brackets.