Mercury 2009 Mountaineer Owner's Manual page 268

Driving
WARNING: Always set the parking brake fully and make sure
that the gearshift is securely latched in P (Park).
WARNING: If the parking brake is fully released, but the brake
warning lamp remains illuminated, the brakes may not be
working properly. See your authorized dealer.
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 applies only the
rear brakes, the vehicle's stopping distance will increase greatly and the
handling of your vehicle will be adversely affected.
Pull the release lever to release the
brake. Driving with the parking
brake on will cause the brakes to
wear out quickly and reduce fuel
economy.
268
2009 Mountaineer (mnt)
Owners Guide, 2nd Printing
USA (fus)