83-161

Heater Hose Clearance
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado

Freightliner
Service Bulletin

> Business Class M2
Cascadia
108SD/114SD
New Cascadia

General Information
Some Business Class M2 106 vehicles built from January 2017 through June 2021 may have a heater hose
installed too close to the electric horn. This applies to Business Class M2 106 vehicles with a 160 mm cab
equipped with Cummins ISB engines and either single or dual horns. It also applies to heater systems with or
without automatic shut-off valves. Horn failures have been reported due to high heat produced by the heater
hose. In some cases, the horn comes in direct contact with the heater hose. See Fig. 1.

1

2

08/11/2021

1. Electric Horn

f832232

2. Heater Hose

Fig. 1, Heater Installation with Close Proximity to
Electric Horn

Heater Hose Modification
1. Park the vehicle on a level surface, shut down the engine, and apply the parking brake. Chock the tires.
2. With the ignition switch ON, check for proper operation of the horn(s). If the horn does not sound, or sound
is weak, dull or abnormal, replace the horn(s) following the Horn Replacement procedure below.
3. Disconnect the batteries.
4. Open the hood to access the heater hose installation.
5. Drain the coolant.
6. Remove the coolant hose as follows.
6.1

Remove the clamp opposite the 45 degree fitting, as shown in Fig. 2.

Freightliner Service Bulletin, 08/25/2021

Page 1

83-161
Freightliner
Service Bulletin

Heater Hose Clearance
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado

> Business Class M2
Cascadia
108SD/114SD
New Cascadia

2
1

08/05/2021

f832233

1. Coolant Hose Clamp
2. 45° Hose Fitting
Fig. 2, Original Heater Hose Installation

6.2

Remove the 45 degree fitting, shown in Fig. 2. Use a wrench to hold the end of the heater coolant
supply tube as you remove the fitting.

7. Install the tube reflecting sleeve (part number BEN 476445028) on the heater hose and secure it with tie
straps. See Fig. 3.

08/11/2021

f832234

Fig. 3, Tube Reflecting Sleeve

Page 2

Freightliner Service Bulletin, 08/25/2021

83-161

Heater Hose Clearance
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado

Freightliner
Service Bulletin

> Business Class M2
Cascadia
108SD/114SD
New Cascadia

NOTE: The additional 90 degree fitting is not required if the heater coolant system is equipped with
an optional supply shut-off valve. In this case, only install the tube reflecting sleeve.
8. Attach the 90 degree fitting (part number 210503 000027) under the 45 degree fitting. See Fig. 4.

08/05/2021

f832235

The completed assembly is shown without the tube
reflecting sleeve for clarity, so that the 90 degree fitting
can be seen.
Fig. 4, Updated Heater Hose Installation

8.1

To prevent coolant leaks, apply Loctite® 592 thread sealant to both the 90 degree fitting and the 45
degree fitting before assembly. See Fig. 5.

08/16/2021

f832236

Fig. 5, Loctite 592 Thread Sealant

8.2

Tighten the fitting assembly by hand.

8.3

Using a wrench to hold the end of the coolant supply tube, attach the fitting assembly to the tube.
Tighten the fitting assembly 40 lbf·ft (54 N·m).

Freightliner Service Bulletin, 08/25/2021

Page 3

83-161

Heater Hose Clearance

Freightliner
Service Bulletin

8.4

FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado

> Business Class M2
Cascadia
108SD/114SD
New Cascadia

Attach the heater hose to the fitting assembly and secure it with a clamp (part number 23-09796309).

Parts
See Table 1 for a list of required parts.

Part Number
BEN 476445028
210503 000027
23-09796-309

Parts Table
Part Description
TUBE-RFLT SLEEVE,1.50",HTSHD
ELB-ST 90 08 MPT X 08 F
CLAMP-CABLE TIE,1-3/4X8

Quantity
1.3 feet
1
4

Table 1, Parts Table

Horn Replacement
If the horn inspection indicates that horn replacement is necessary, perform the following steps.
1. Unplug the horn harness.
2. Remove the two fastener and washer hardware sets. See Fig. 6.

1

2

1

2

08/18/2021

1. Horn Harness

f547602

2. Fastener and Washer Hardware
Fig. 6, Single- and Dual-Horn Installation

3. Replace the single or dual horn part numbers with same part number, or replacement part, per available
Paragon information. Use removed hardware to install. Tighten the fasteners 48 to 60 lbf·in (542 to 678
N·cm).

Warranty
This procedure is warrantable only if the described condition exists and the repair is performed within the
applicable base or extended coverage warranty period. If a failure is not found, this procedure is considered
preventive and warranty does not apply.

Page 4

Freightliner Service Bulletin, 08/25/2021

83-161

Heater Hose Clearance
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado

> Business Class M2
Cascadia
108SD/114SD
New Cascadia

Freightliner
Service Bulletin

Normal warranty applies. See Table 2 for OWL VMRS codes and labor allowance information. Enter this service
bulletin number in the Service Bulletin # field.

Primary Failed
Part
66-01788-002/
003/004/005

OWL VMRS Codes and Labor Allowance
Component
Correction
Cause Code
SRT Code
Description
Code
Code
03 38 REPLACE 726-6010A HORN, ELEC, R/R
054-001-042
SHORTED
WITH NEW

Time: Hours
0.3

Table 2, OWL VMRS Codes and Labor Allowance

Freightliner Service Bulletin, 08/25/2021

Page 5