SB-49-12
Service Bulletin/Repair Instructions
WESTERN STAR: AROUND THE DIESEL EXHAUST FLUID (DEF) AN EXCESSIVE AMOUNT OF CRYSTAL OR POWDER BUILT UP INDICATES A LEAK CAUSED BY EVAPORATION OF DEF EXPOSED TO AIR AND/OR DAMPNESS. *PE
Vehicle report
Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.
SB-49-12
WESTERN STAR: AROUND THE DIESEL EXHAUST FLUID (DEF) AN EXCESSIVE AMOUNT OF CRYSTAL OR POWDER BUILT UP INDICATES A LEAK CAUSED BY EVAPORATION OF DEF EXPOSED TO AIR AND/OR DAMPNESS. *PE
SB-88-11
WESTERN STAR TRUCK: SOME TRUCKS (4900FA, 123BBC) WITH HOOD SALES CODE 644-002, MAY DEVELOP CRACKS AT THE INNER FENDER, NEAR THE NUTPLATE FOR THE HOOD GUIDE. THE STEEL PIVOT STRUCTURE CAN ALSO CRACK, OUTBOARD OF THE HOOD PIVOT CLEVIS. NO MODEL YEARS LISTED. *PE
Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.