brake GMC SONOMA 2003 Owner's Guide

Off-Road Driving with Your
Four-Wheel-Drive Vehicle
This off-road guide is for vehicles that have four-wheel
drive.
Also, seeAnti-Lock BrakesunderBraking on page 4-5.
If your vehicle doesn’t have four-wheel drive, you
shouldn’t drive off-road unless you’re on a level, solid
surface.
Off-road driving can be great fun. But it does have
some denite hazards. The greatest of these is
the terrain itself.
'Off-roading' means you’ve left the great North American
road system behind. Traffic lanes aren’t marked.
Curves aren’t banked. There are no road signs.
Surfaces can be slippery, rough, uphill or downhill.
In short, you’ve gone right back to nature.
Off-road driving involves some new skills. And that’s
why it’s very important that you read this guide.
You’llnd many driving tips and suggestions. These will
help make your off-road driving safer and more
enjoyable.
Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields (if so equipped) are properly
attached. Be sure you read all the information about
your four-wheel-drive vehicle in this manual. Is
there enough fuel? Is the spare tire fully inated?
Are theuid levels up where they should be? What are
the local laws that apply to off-roading where you’ll
be driving? If you don’t know, you should check with law
enforcement people in the area. Will you be on
someone’s private land? If so, be sure to get the
necessary permission.
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{CAUTION:
Driving to the top (crest) of a hill at full speed
can cause an accident.There could be a
drop-off, embankment, cliff, or even another
vehicle.You could be seriously injured or
killed.As you near the top of a hill, slow down
and stay alert.
Q:What should I do if my vehicle stalls, or is
about to stall, and I can’t make it up the hill?
A:If this happens, there are some things you should
do, and there are some things you must not do.
First, here’s what youshoulddo:
Push the brake pedal to stop the vehicle and keep
it from rolling backwards. Also, apply the parking
brake.
If your engine is still running, shift the transmission
to REVERSE (R), release the parking brake, and
slowly back down the hill in REVERSE (R).
If your engine has stopped running, you’ll need to
restart it. With the brake pedal pressed and the
parking brake still applied, shift the transmission to
PARK (P) (or shift to neutral if your vehicle has
a manual transmission) and restart the engine.Then, shift to REVERSE (R), release the parking
brake, and slowly back down the hill as straight as
possible in REVERSE (R).
As you are backing down the hill, put your left hand
on the steering wheel at the 12 o’clock position.
This way, you’ll be able to tell if your wheels
are straight and maneuver as you back down.
It’s best that you back down the hill with your wheels
straight rather than in the left or right direction.
Turning the wheel too far to the left or right
will increase the possibility of a rollover.
Here are some things youmust notdo if you stall,
or are about to stall, when going up a hill.
Never attempt to prevent a stall by shifting into
NEUTRAL (N) (or pressing the clutch, if you have a
manual transmission) to“rev-up”the engine and
regain forward momentum. This won’t work.
Your vehicle will roll backwards very quickly and
you could go out of control.
Instead, apply the regular brake to stop the
vehicle. Then apply the parking brake. Shift to
REVERSE (R), release the parking brake,
and slowly back straight down.
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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
PARK (P) (or the manual transmission in
FIRST (1)) 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.
Driving Downhill
When off-roading takes you downhill, you’ll want to
consider a number of things:
How steep is the downhill? Will I be able to maintain
vehicle control?
What’s the surface like? Smooth? Rough? Slippery?
Hard-packed dirt? Gravel?
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?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 won’t 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’s not too steep
to drive down may be too steep to drive across. You
could roll over if you don’t drive straight down.
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Never go downhill with the transmission in
NEUTRAL (N), or with the clutch pedal pressed
down in a manual shift. 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’s much more likely to happen going uphill. But if
it happens going downhill, here’s what to do.
Stop your vehicle by applying the regular brakes.
Apply the parking brake.
Shift to PARK (P) (or to neutral with the manual
transmission) and, while still braking, restart the
engine.
Shift back to a low gear, release the parking brake,
and drive straight down.
If the engine won’t start, get out and get help.
Driving Across an Incline
Sooner or later, an off-road trail will probably go
across the incline of a hill. If this happens, you have to
decide whether to try to drive across the incline.
Here are some things to consider:
A hill that can be driven straight up or down may be
too steep to drive across. When you go straight up
or down a hill, the length of the wheel base (the
distance from the front wheels to the rear wheels)
reduces the likelihood the vehicle will tumble
end over end. But when you drive across an incline,
the much more narrow track width (the distance
between the left and right wheels) may not prevent
the vehicle from tilting and rolling over. Also,
driving across an incline puts more weight on the
downhill wheels. This could cause a downhill
slide or a rollover.
Surface conditions can be a problem when you
drive across a hill. Loose gravel, muddy spots,
or even wet grass can cause your tires to slip
sideways, downhill. If the vehicle slips sideways,
it can hit something that will trip it (a rock, a rut, etc.)
and roll over.
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Driving in Water
Heavy rain can meanashooding, andood waters
demand extreme caution.
Find out how deep the water is before you drive through
it. If it’s deep enough to cover your wheel hubs, axles
or exhaust pipe, don’t try it—you probably won’t
get through. Also, water that deep can damage your
axle and other vehicle parts.
If the water isn’t too deep, drive slowly through it. At faster
speeds, water splashes on your ignition system and your
vehicle can stall. Stalling can also occur if you get your
tailpipe under water. And, as long as your tailpipe is
under water, you’ll never be able to start your engine.
When you go through water, remember that when your
brakes get wet, it may take you longer to stop.
{CAUTION:
Driving through rushing water can be
dangerous.Deep water can sweep your vehicle
downstream and you and your passengers
could drown.If it’s only shallow water, it can
CAUTION: (Continued)
CAUTION: (Continued)
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over.Don’t drive through rushing
water.
SeeDriving in Rain and on Wet Roads on page 4-28for
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 are 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.
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The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are in good shape, a heavy
rain can make it harder to see road signs and
traffic signals, pavement markings, the edge of the road
and even people walking.
It’s wise to keep your wiping equipment in good shape
and keep your windshield washer tanklled with
washeruid. Replace your windshield wiper inserts
when they show signs of streaking or missing areas on
the windshield, or when strips of rubber start to
separate from the inserts.Driving too fast through large water puddles or even
going through some car washes can cause problems,
too. The water may affect your brakes. Try to avoid
puddles. But if you can’t, try to slow down before you
hit them.
{CAUTION:
Wet brakes can cause accidents.They won’t
work as well in a quick stop and may cause
pulling to one side.You could lose control of
the vehicle.
After driving through a large puddle of water
or a car wash, apply your brake pedal lightly
until your brakes work normally.
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If you drive regularly in steep country, or if you’re
planning to visit there, here are some tips that can make
your trips safer and more enjoyable. SeeOff-Road
Driving with Your Four-Wheel-Drive Vehicle on
page 4-13for information about driving off-road.
Keep your vehicle in good shape. Check alluid
levels and also the brakes, tires, cooling system
and transmission. These parts can work hard
on mountain roads.
Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when you
go down a steep or long hill.
{CAUTION:
If you don’t shift down, your brakes could get
so hot that they wouldn’t work well. You would
then have poor braking or even none going
down a hill. You could crash. Shift down to let
your engine assist your brakes on a steep
downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have
to do all the work of slowing down. They
couldget so hot that they wouldn’t work well.
You would then have poor braking or even
none going down a hill. You could crash.
Always have your engine running and your
vehicle in gear when you go downhill.
Know how to go uphill. You may want to shift down to
a lower gear. The lower gears help cool your engine
and transmission, and you can climb the hill better.
Stay in your own lane when driving on two-lane
roads in hills or mountains. Don’t swing wide or cut
across the center of the road. Drive at speeds that let
you stay in your own lane.
As you go over the top of a hill, be alert. There could
be something in your lane, like a stalled car or an
accident.
You may see highway signs on mountains that warn
of special problems. Examples are long grades,
passing or no-passing zones, a falling rocks area or
winding roads. Be alert to these and take appropriate
action.
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Driving on Snow or Ice
Most of the time, those places where your tires meet
the road probably have good traction.
However, if there is snow or ice between your tires and
the road, you can have a very slippery situation.
You’ll have a lot less traction or“grip”and will need to
be very careful.
What’s the worst time for this?“Wet ice.”Very cold
snow or ice can be slick and hard to drive on. But wet
ice can be even more trouble because it may offerthe least traction of all. You can get wet ice when it’s
about freezing (32°F; 0°C) and freezing rain begins
to fall. Try to avoid driving on wet ice until salt and sand
crews can get there.
Whatever the condition—smooth ice, packed, blowing
or loose snow—drive with caution.
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.
Your anti-lock brakes improve your vehicle’s stability
when you make a hard stop on a slippery road.
Even though you have an anti-lock braking system,
you’ll want to begin stopping sooner than you would on
dry pavement. SeeBraking on page 4-5.
Allow greater following distance on any slippery road.
Watch for slippery spots. The road might bene until
you hit a spot that’s covered with ice. On an
otherwise clear road, ice patches may appear in
shaded areas where the sun can’t reach: around
clumps of trees, behind buildings or under bridges.
Sometimes the surface of a curve or an overpass
may 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’re
actually on the ice, and avoid sudden steering
maneuvers.
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When towing your vehicle, turn the ignition to OFF.
To prevent your battery from draining while towing,
remove the RDO BATT and CLSTR fuses from
the instrument panel fuse block. Be sure to replace the
fuse when you reach your destination. SeeFuses
and Circuit Breakers on page 5-89. Be sure to use the
proper towing equipment designed for recreational
vehicle towing. Follow the instructions for the towing
equipment.
{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) for
an automatic transmission, or if your vehicle is
in gear, for a manual transmission. You or
others could be injured. Make sure the parking
brake isfirmly set before you shift the transfer
case to NEUTRAL.
If your vehicle has four-wheel-drive it cannot be dinghy
towed. A four-wheel-drive vehicle must be towed by
atbed.
Dolly Towing
Notice:Towing your vehicle with all four wheels on
the ground will damage drivetrain components.
Your two-wheel-drive vehicle should not be towed with
two wheels on the ground. Your transmission has no
provision for internal lubrication while being towed.
To properly tow your vehicle, it should be placed on a
platform trailer with all four wheels off the ground. Towing
with all four wheels on the ground should be avoided.Two-Wheel-Drive Vehicles Only
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In rare cases when it’s unavoidable and your vehicle
must be towed with two wheels on the ground, the
propeller shaft to axle yoke orientation should be marked
and the propeller shaft removed following the applicable
service manual removal/installation procedure. See
Service Publications Ordering Information on page 7-9.
Dust or dirt can enter the back of the transmission
through the opening created by removing the propeller
shaft if proper protection is not provided. Also, check
the transmissionuid level before driving the vehicle.
Use the following steps to dolly tow your vehicle:
1. Put the front wheels on a dolly.
2. Put the vehicle in PARK (P).
3. Set the parking brake and then remove the key.
4. Disconnect the propshaft as described above.
5. Clamp the steering wheel in a straight-ahead
position with a clamping device designed for towing.
6. Release the parking brake.Be sure to use the proper towing equipment designed
for recreational vehicle towing. Follow the instructions for
the towing equipment.
{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) for
an automatic transmission, or if your vehicle is
in gear, for a manual transmission. You or
others could be injured. Make sure the parking
brake isfirmly set before you shift the transfer
case to NEUTRAL.
If your vehicle has four-wheel-drive it cannot be dolly
towed. A four-wheel-drive vehicle must be towed
byatbed.
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