GMC Envoy Owner's Manual page 300

•
Are there hidden surface obstacles? Ruts? Logs?
Boulders?
•
What is at the bottom of the hill? Is there
a hidden creek bank or even a river bottom
with large rocks?
If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a
low gear. This way, engine drag can help your brakes
and they will not have to do all the work. Descend
slowly, keeping your vehicle under control at all times.
CAUTION:
{
Heavy braking when going down a hill can
cause your brakes to overheat and fade. This
could cause loss of control and a serious
accident. Apply the brakes lightly when
descending a hill and use a low gear to keep
vehicle speed under control.
Q:
Are there some things I should not do when
driving down a hill?
A:
Yes! These are important because if you ignore them
you could lose control and have a serious accident.
•
When driving downhill, avoid turns that take you
across the incline of the hill. A hill that is not too steep
to drive down may be too steep to drive across. You
could roll over if you do not drive straight down.
•
Never go downhill with the transmission in
NEUTRAL (N). This is called "free-wheeling."
Your brakes will have to do all the work and
could overheat and fade.
Q:
Am I likely to stall when going downhill?
A:
It is much more likely to happen going uphill.
But if it happens going downhill, here is what to do.
1. Stop your vehicle by applying the regular brakes.
Apply the parking brake.
2. Shift to PARK (P) and, while still braking, restart
the engine.
3. Shift back to a low gear, release the parking brake,
and drive straight down.
4. If the engine will not start, get out and get help.
4-25