TTER RECOMMENDED MOS 22-JUL-2014 SL 737-SL-73-014 ENGINE RATING CHECK. SERVICE LETTER RECOMMENDED MOS 12-AUG-1998 - (s) SL 737-SL-73-017 HYDRO-MECHANICAL UNIT P/N 1853M56P08. SERVICE LETTER MOS 13-MAR-2002 - (s) SI. 737-SL-73-018 IMPROVED FUEL FILTER DIFFERENTIAL PRESSURE SWITCH. TO REDUCE FALSE ENGINE FUEL FILTER B