GMC 2001 Yukon XL Owner's Manual page 107

To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge of the lever, located
above the parking brake pedal, marked BRAKE
RELEASE, to release the parking brake.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
NOTICE:
Driving with the parking brake on can cause
your rear brakes to overheat. You may have to
replace them, and you could also damage other
parts of your vehicle.
If you are towing a trailer and are parking on any hill,
see "Towing a Trailer" in the Index. That section shows
what to do first to keep the trailer from moving.
Shifting Into PARK (P)
CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle won't move, even
when you're on fairly level ground, use the steps
-
that follow. With four
transfer case is in NEUTRAL, your vehicle will
be free to roll, even if your shift lever is in
PARK (P). So, be sure the transfer case is in a
--
drive gear not in NEUTRAL. If you're pulling
a trailer, see "Towing a Trailer" in the Index.
wheel drive if your
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