GMC 1994 Yukon Owner's Manual page 203

Parking on Hills
You really should not park your vehicle, with a trailer attached, on a hill. If
something goes wrong, your rig could start to move. People can be injured,
and both your vehicle and the trailer can be damaged.
But if you ever have to park your rig on a hill, here's how to do it:
I . Apply your regular brakes, but don't shift into
" P '
(Park) yet, or in gear
2. Have someone place chocks under the trailer wheels.
3.
When the wheel chocks are in place, release the regular brakes until the
for a manual transmission.
chocks absorb the load.
4. Re-apply the regular brakes. Then apply your parking brake, and then
shift to "P" (Park), or
" R 7
(Reverse) for a manual transmission.
5. If you have a four-wheel-drive vehicle, be sure the transfer case is in a
drive gear-not in
" N 7
(Neutral).
6.
Release the regular brakes.
I
.
, , , , ,
.
.I
.
. .
.. .
. .
.
.. .
..
. I
4-43