FORD 2013 F-550 v.3 - Manual (Page 357)

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 regulations. For example, during any procedure
involving tire inflation, the technician or individual must utilize a remote
inflation device, and make sure that all persons are clear of the
trajectory area.
356 Wheels and Tires
2013 F-250/350/450/550 (f23)
Owners Guide gf, 3rd Printing, December 2012
USA (fus)