Drain Main Engine Crankcase.
Drain engine oil only when hot after operation.
Periodically, a sample of oil shall be sent to the AOAP laboratory for analysis.
Oil is to be drained after every 25 hours of operation or every 30 days,
whichever comes first (refer to TB 430210). If laboratory is not available, hard
time intervals will apply.
When AOAP laboratory support is not available, drain and refill transmission
oil at 1500 miles (2414 km), 150 hours, or semiannually if OE/HDO is used (750
miles [1207 km], 75 hours, or quarterly if OEA is used).
Coordinate any seasonal change of oil weight with this service.
Ensure vehicle is on level ground.
Remove oil cooler vent cap screw and open oil filter drain valve.
Remove six screws (19) and six lockwashers (20) from engine drain plate (21) and remove drain plate and