FORD 2011 F-550 v.2 - Manual (Page 219)

6. Visually inspect the tires to make sure there are no nails or other
objects embedded that could poke a hole in the tire and cause an air
leak.
7. Check the sidewalls to make sure there are no gouges, cuts or bulges.
Tire inflation information
All tires with Steel Carcass Plies (if equipped):
This type of tire utilizes steel cords in the sidewalls. As such, they
cannot be treated like normal light truck tires. Tire service, including
adjusting tire pressure, must be performed by personnel trained,
supervised and equipped according to Federal Occupational Safety and
Health Administration (OSHA) regulations. For example, during any
procedure involving tire inflation, the technician or individual must
utilize a remote inflation device, and ensure that all persons are clear of
the trajectory area.
WARNING: An inflated tire and rim can be very dangerous if
improperly used, serviced or maintained. To reduce the risk of
serious injury, never attempt to re-inflate a tire which has been run flat
or seriously under-inflated without first removing the tire from the
wheel assembly for inspection. Do not attempt to add air to tires or
replace tires or wheels without first taking precautions to protect
persons and property.
Tires, Wheels and Loading
219
2011 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)