Ford 2002 F650 Owner's Manual page 116

Driving
The parking BRAKE warning lamp
in the instrument cluster illuminates
and remains illuminated (when the
ignition is turned ON) until the
parking brake is released.
Do not use the gearshift selector in place of the parking brake.
Always set the parking brake fully AND make sure the gearshift
selector is in R (Reverse) for vehicles equipped with manual
transmission, P (Park) (if equipped) or N (Neutral) for vehicles with
automatic transmission. Use of wheel chocks is also recommended in
hilly or off-road usage.
Unexpected and possible sudden vehicle movement may occur if
these precautions are not taken.
The parking brake is not recommended to stop a moving vehicle.
However, if the normal brakes fail, the parking brake can be used to stop
your vehicle in an emergency. Since the parking brake only applies
retardation to the rear wheels, the vehicle's stopping distance will
increase greatly and the handling of your vehicle will be adversely
affected.
116
BRAKE
P