2008 GMC ENVOY brake

Driving in Water
{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
could drown. If it is only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Do not drive through rushing
water.
Heavy rain can mean ash ooding, and ood waters
demand extreme caution.
Find out how deep the water is before you drive through
it. If it is deep enough to cover the wheel hubs, axles,
or exhaust pipe, do not try it — you probably will not get
through. Also, water that deep can damage the axle
and other vehicle parts.If the water is not too deep, drive slowly through it.
At faster speeds, water splashes on the ignition system
and your vehicle can stall. Stalling can also occur if you
get the tailpipe under water. And, as long as the tailpipe
is under water, you will never be able to start the engine.
When you go through water, remember that when the
brakes get wet, it may take you longer to stop.
SeeDriving in Rain and on Wet Roads on page 4-27for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on
the underbody, chassis, or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires, and exhaust system
for damage. Also, check the fuel lines and cooling system
for any leakage.
Your vehicle will require more frequent service due
to off-road use. Refer to the Maintenance Schedule
for additional information.
4-25

Driving in Rain and on Wet Roads
Rain and wet roads can reduce vehicle traction
and affect your ability to stop and accelerate. Always
drive slower in these types of driving conditions
and avoid driving through large puddles and
deep-standing or owing water.
{CAUTION:
Wet brakes can cause crashes. They might not
work as well in a quick stop and could cause
pulling to one side. You could lose control of
the vehicle.
After driving through a large puddle of water
or a car/vehicle wash, lightly apply the brake
pedal until the brakes work normally.
Flowing or rushing water creates strong
forces. Driving through owing water could
cause your vehicle to be carried away. If this
happens, you and other vehicle occupants
could drown. Do not ignore police warnings
and be very cautious about trying to drive
through owing water.
Hydroplaning
Hydroplaning is dangerous. Water can build up under
your vehicle’s tires so they actually ride on the water. This
can happen if the road is wet enough and you are going
fast enough. When your vehicle is hydroplaning, it has
little or no contact with the road.
There is no hard and fast rule about hydroplaning.
The best advice is to slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet weather driving tips
include:
Allow extra following distance.
Pass with caution.
Keep windshield wiping equipment in good shape.
Keep the windshield washer uid reservoir lled.
Have good tires with proper tread depth. SeeTires
on page 5-57.
4-27

Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on at or rolling terrain. Tips for driving
in these conditions include:
Keep your vehicle serviced and in good shape.
Check all uid levels and brakes, tires, cooling
system, and transmission.
Going down steep or long hills, shift to a
lower gear.
{CAUTION:
If you do not shift down, the brakes could get
so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Shift down
to let the engine assist the brakes on a steep
downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. The brakes will have
to do all the work of slowing down and they
could get so hot that they would not work well.
You would then have poor braking or even
none going down a hill. You could crash.
Always have the engine running and your
vehicle in gear when you go downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
SeeOff-Road Driving on page 4-13for information
about driving off-road.
4-29

Accelerate gently. Try not to break the fragile traction.
If you accelerate too fast, the drive wheels will spin and
polish the surface under the tires even more.
The Antilock Brake System (ABS) improves your
vehicle’s stability when you make a hard stop on a
slippery road. Even though you have ABS, begin
stopping sooner than you would on dry pavement.
SeeAntilock Brake System (ABS) on page 4-4.
Allow greater following distance on any
slippery road.
Watch for slippery spots. The road might be ne
until you hit a spot that is covered with ice. On an
otherwise clear road, ice patches can appear in
shaded areas where the sun cannot reach, such as
around clumps of trees, behind buildings, or under
bridges. Sometimes the surface of a curve or an
overpass can remain icy when the surrounding roads
are clear. If you see a patch of ice ahead of you,
brake before you are on it. Try not to brake while you
are actually on the ice, and avoid sudden steering
maneuvers.
If You Are Caught in a Blizzard
If you are stopped by heavy snow, you could be in a
serious situation. You should probably stay with your
vehicle unless you know for sure that you are near help
and you can hike through the snow. Here are some things
to do to summon help and keep yourself and your
passengers safe:
Turn on the hazard warning ashers.
Tie a red cloth to your vehicle to alert police that you
have been stopped by the snow.
Put on extra clothing or wrap a blanket around you.
If you do not have blankets or extra clothing, make
body insulators from newspapers, burlap bags, rags,
oor mats — anything you can wrap around yourself
or tuck under your clothing to keep warm.
4-31

Adding a Snow Plow or Similar
Equipment
Your vehicle was neither designed nor intended for a
snow plow.
Notice:Adding a snow plow or similar equipment
to your vehicle can damage it, and the repairs would
not be covered by warranty. Do not install a snow
plow or similar equipment on your vehicle.
Towing
Towing Your Vehicle
Consult your dealer/retailer or a professional towing
service if you need to have your disabled vehicle towed.
SeeRoadside Assistance Program on page 7-8.
If you want to tow your vehicle behind another vehicle
for recreational purposes (such as behind a motorhome),
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle – such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as “dinghy towing” (towing your vehicle
with all four wheels on the ground) and “dolly towing”
(towing your vehicle with two wheels on the ground
and two wheels up on a device known as a “dolly”).
With the proper preparation and equipment, many
vehicles can be towed in these ways. See “Dinghy
Towing” and “Dolly Towing,” following. You may also
need brakes for the vehicle being towed. See your
dealer for additional trailering information.
Here are some important things to consider before you
do recreational vehicle towing:
What’s the trailering capacity of the towing vehicle?
Be sure you read the tow vehicle manufacturer’s
recommendations.
How far will you tow? Some vehicles have
restrictions on how far and how long they can
be towed.
Do you have the proper towing equipment? See
your dealer or trailering professional for additional
advice and equipment recommendations.
Is your vehicle ready to be towed? Just as you
would prepare your vehicle for a long trip, you’ll
want to make sure your vehicle is prepared to be
towed. SeeBefore Leaving on a Long Trip on
page 4-28.
4-40

Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If you tow your vehicle with all four wheels
on the ground, the drivetrain components could
be damaged. The repairs would not be covered by
your warranty. Do not tow your vehicle with all
four wheels on the ground.
Two-wheel-drive vehicles should not be towed with
all four wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed. To properly tow these vehicles, they
should be placed on a platform trailer.
Four-Wheel-Drive Vehicles
Four-wheel-drive vehicles can be dinghy towed if you
follow the proper procedures. The transmission has
no provisions for internal lubrication while being towed,
so it is important that you follow all the steps listed
in this manual to dinghy tow your four-wheel-drive
vehicle.
Use the following procedure to tow your vehicle:
1. Shift the transmission to PARK (P).
2. Turn the engine off, but leave the ignition on.
3. Firmly set the parking brake.
4-41

4. Securely attach the vehicle being towed to the tow
vehicle.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
5. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-29for the proper
procedure to select the NEUTRAL (N) position
for your vehicle.
6. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
7. Turn the ignition off.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-29.
Dolly Towing
Front Towing (Front Wheels Off
the Ground)
Two-Wheel-Drive Vehicles
Notice:If you tow a two-wheel-drive vehicle with
the rear wheels on the ground, the transmission
could be damaged. The repairs would not be
covered by your warranty. Never tow your vehicle
with the rear wheels on the ground.
Four-Wheel-Drive Vehicles
Four-wheel-drive vehicles can be dolly towed with the
rear wheels on the ground.
Use the following procedure to tow your vehicle:
1. Drive the vehicle onto the tow dolly.
2. Shift the automatic transmission to PARK (P).
3. Turn the engine off, but leave the ignition on.
4. Firmly set the parking brake.
5. Securely attach the vehicle being towed to
the dolly.
4-42

{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
6. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-29for the proper
procedure to select the NEUTRAL (N) position for
your vehicle.
7. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
8. Turn the ignition off.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-29.
Rear Towing (Rear Wheels Off
the Ground)
(Two-Wheel or Four-Wheel-Drive Vehicles)
Use the following procedure to tow your vehicle from
the rear:
1. Drive the vehicle onto the dolly.
2. Firmly set the parking brake. SeeParking Brake on
page 2-33for more information.
3. Shift the transmission in PARK (P).
4-43