Ford F-650 Owner's Manual page 130

Driving
Tractor-trailer connections
WARNING: To reduce the risk of personal injury, use extreme
caution when making brake and light connections. Inclement
weather and accumulated road contamination deposits on handhold
and stepping surfaces require extra care to avoid slip and falls. Provide
adequate lighting of working areas.
WARNING: Do not climb on the back of the tractor unless it
has been provided with a deck plate and handholds. Use a
three-point stance when climbing up and down from a deck plate. Do
not jump from the vehicle. Whenever possible, make all connections
while standing on the ground.
Connecting and disconnecting a trailer with air suspension and air
suspension dump switch (if equipped)
When connecting to a trailer:
• Press the lower portion of the dump switch to exhaust air from the air
suspension system.
• After making the connection to the trailer, press the upper portion of
the dump switch, then raise the landing gear.
When disconnecting the trailer:
• Lower the landing gear, then press the lower portion of the dump switch.
• Disconnect the brake hoses, trailer-side and rear light connectors,
then pull the release lever on the fifth-wheel.
The upper portion of the dump switch must be pressed before operating
with a trailer or operating in the bobtail mode.
Suspension conversions
It is not recommended, or approved, that suspension conversions be
performed. However, it is understood that, on occasion, aftermarket add-on
suspensions are installed by others on the truck chassis which allow
operator control for weight transfer from other axles (i.e., air lift axles).
WARNING: When operating a loaded vehicle, the driver must
keep all adjustable axles on the ground at all times, supporting
their share of the vehicle's load. Failure to do so can overload other
axles, tires, wheels, springs, steering components, brakes and frames,
resulting in early component failure, loss of vehicle control, possible
property damage and personal injury.
130
2012 F-650/750 (f67)
Supplement, 2nd Printing
USA (fus)