Service Bulletin No. 548 A

Diaphragm-Type Fuel Pump Inspection/Replacement

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August 31, 2005


New, rebuilt and overhauled engines from Lycoming with fuel pumps P/N LW-15399, LW-15472, LW-15473, and LW-16335 shipped between February 1, 2000 and September 15, 2005. Engine models affected are O- 235; O-290; O-340; (L)O and IO-320, -360, -540; AIO-320, -360; AEIO-320, -360, -540; HO-360; HIO-360; and TO-360.

Fuel pumps P/N LW-15399, LW-15472, LW-15473, and LW-16335 purchased through distribution between February 22, 2000 and September 15, 2005.


Compliance is required within 180 calendar days from the date of this Service Bulletin, or as specified below, whichever occur first:

1. Inspect within 50 hours of operation:

2. If affected, replace within 100 hours of operation or earlier at owner’s discretion.

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