SB 449

Service Bulletin No. 449
MODEL
TYPE
J4500
SECTION/GROUP
Field Change Program
DATE
3-Body
April 13, 2017
SUBJECT
RH DASH ASSEMBLY DEFROSTER VENTS
CONDITIONS
Customer Complaint:
Motor Coach Industries ("MCI") has become aware that the J4500 series coaches listed in this bulletin may
experience damage to the RH dash assembly defroster ( diffuser ) vents as a result of passenger contact
entering and exiting the coach cabin.
Cause:
Existing defroster vent composite strength.
Corrective Action:
As a result, MCI strongly urges owners of the MY 2015, MY 2016 and MY2017 J4500 model coaches listed in this
bulletin to implement the steps in this procedure as soon as possible
66972 to 68228
Parts
Qty.
New P/N
Description
1
16-14-1678
Vent, Defroster / Diffuser, Dash
2
16-14-1679
Vent, Defroster / Diffuser, Dash
6
19-01-1895
Screw
Service Procedure:
Read this entire procedure before beginning work.
Use Safe Shop Practices At All Times.
Service Bulletin No. 449
Date Apr. 13, 2017
Page 2
1. Turn the main battery disconnect to the OFF position.
2. Chock both sides of the tires.
3. Enter the coach cabin.
4. Locate the three ( 3 ) defroster vents on the RH dash assembly shown in Figure 1.
3
3
2
1
Figure 1. Defroster vents located on upper face of the RH dash assembly.
Item
Figure 1 Description
1
RH dash assembly
2
Defroster vent, p/n 16-14-1678. Larger profile opening.
3
Defroster vent, p/n 16-14-1679. Smaller profile opening.
5. Carefully remove and discard the defroster vent mounting screws. Carefully lift upwards to remove the
defroster vent from the RH dash assembly. Discard the defroster vent.
6. Orient the new defroster vent, p/n 16-14-1678, in the larger open cavity shown as Item 2 in Figure 1.
Using new screws, p/n 19-01-1895, secure the defroster vent to the RH dash assembly. Tighten screws
to secure.
7. Repeat Steps 5 and 6 to the new defroster vents, p/n 16-14-1679, in the smaller open cavity shown as Item
3 in Figure 1.
Procedure Complete.
Service Bulletin No. 449
Date Apr. 13, 2017
Page 3
Field Change Program Conditions:
The parts required for this rework will be supplied without charge.
No labor allowance will be granted for this rework on affected J4500 model coaches.
This program will end on October 31, 2017.
Motor Coach apologizes for any inconvenience resulting from this campaign, but urges you to implement this
change as soon as possible.
Sincerely,
Motor Coach Industries