GMC SIERRA 1994 Manual page 183

Instead, apply the regular brake to stop the vehicle. Then apply the parking
brake. Shift into reverse, release the parking brake, and slowly back straight
down.
Never attempt to turn around if you are about to stall when going up a
hill. If the hill is steep enough to stall your vehicle, it's steep enough to
cause you to roll over if you turn around. If you can't make
it
up the
hill, you must back straight down the hill.
Q:
Suppose, after stalling, I try to back down the hill and decide I just
can't do it. What should I do?
A:
Set the parking brake, put your transmission in "P" (Park) (or the
manual transmission in first gear)
,
and turn off the engine. Leave the
vehicle and go get some help. Exit on the uphill side and stay clear of
the path the vehicle would take if it rolled downhill. Do not shift the
transfer case to "N" (Neutral) when you leave the vehicle. Leave it in
some gear.
Driving Downhill
When off-roading takes you downhill, you'll want to consider a number of
things:
Are there hidden surface obstacles? Ruts'? Logs? Boulders?
What's at the bottom of the hill? Is there a hidden creek bank or even a
river bottom with large rocks?
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