FORD F-250 - Manual (Page 193)

Use only fluid that meets Ford specifications. Refer to the Capacities
and specifications chapter.
AIR FILTER MAINTENANCE
Refer to the Scheduled Maintenance Guide for the appropriate intervals
for changing the air filter element.
When changing the air filter element, use only the Motorcraft air filter
element listed. Refer to Motorcraft Part Numbers in the Capacities and
specifications chapter.
Do not start your engine with the air cleaner removed and do
not remove it while the engine is running.
Changing the air filter element
1. Loosen the clamp that secures
the air filter element in place.
Maintenance and care
193