Beginning with coach unit number 53455, MCI modified the coach air system by installing a coalescing filter and bypass valve to all "D/DL" model coaches. The purpose of this filter is to improve the coach air quality and the valve assembly is used to bypass the air dryer in the case of freeze-up during cold weather.
MCI Service Parts has put together a retrofit kit for use on D/DL models prior to unit 53455. This kit includes all parts for adding the filter/bypass valve assembly, and tell tale light mounted on the dash. Part numbers are 4L-7-129 for the Bypass Retrofit Kit and 7L-14-0145 for the Electrical Installation Kit.
MCI Publications has issued a Service Bulletin #2790, which includes the installation instructions for retrofitting your coach.
If you have any questions, please call the MCI Customer Support Center at (800) 241-2947.
Motor Coach Industries - A New Flyer company: Corporate Address 200 East Oakton Street, Des Plaines, Illinois 60018 | Phone: 866-MCICOACH
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