Ford 1999 Wagon-Econoline Owner's Manual page 109

Do not rock the vehicle for more than a few minutes. The
transmission and tires may be damaged or the engine may
overheat.
Always set the parking brake fully and make sure the gearshift is
latched in P (Park). Turn off the ignition whenever you leave
your vehicle.
If the parking brake is fully released, but the brake warning lamp
remains illuminated, the brakes may not be working properly.
See your dealer or a qualified service technician.
Driving with a 4–speed automatic transmission
Understanding gearshift positions
Pull the gearshift lever towards you and downward to move the
automatic gearshift.
Hold the brake pedal down while you move the gearshift lever
from P (Park) to another position. If you do not hold the brake
pedal down, your vehicle may move unexpectedly and injure someone.
P (Park)
Always come to a complete stop
before shifting into P (Park). Make
sure the gearshift is securely latched
in P (Park). This position locks the
transmission and prevents the rear
wheels from turning.
Always set the parking brake fully and make sure the gearshift is
securely latched in P (Park).
Never leave your vehicle unattended while it is running.
Driving
109