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Service bulletin SF-421-F-K REV

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10036727
Published by NHTSA2011-04-11
Manufacturer's numberSF-421-F-K REV
Manufacturer's date2011-08-01
ReplacesSF-421F-M REV2
NHTSA componentUNKNOWN OR OTHER

NHTSA's summary

FREIGHTLINER: IITIATING FIELD SERVICE CAMPAIGN TO MODIFY THE VEHICLES MENTIONED. CERTAIN TRUCKS WITH EARLY PRODUCTION PARKSMART PARKED HVAC UNITS MAY NOT PERFORM OPTIMALLY UNDER ALL CONDITIONS. A RANGE OF UPDATES TO ENHANCE PARKED HVAC PERFORMANCE HAVE BEEN IMPLEMENTED SINCE THE START OF PARKSMART PRODUCTION. *PE UPDATED 10/3/11. *PE

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Vehicles listed
FREIGHTLINER CASCADIA2008, 2009, 2010

Listing a model year does not mean every vehicle of it is concerned: the document says which.