brake GMC SAVANA 1997 Owner's Manual

Control of a Vehicle
You have three systems that make your vehicle go where
you want
it to go. They are the brakes, the steering and
the accelerator. All three systems have to do their work
at the places where the tires meet the road.
Sometimes, as when you’re driving on snow or ice, it’s
easy to ask more of those control systems than the tires
and road can provide. That means you can lose control
of your vehicle.
Braking
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake pedal.
That’s
perception time. Then you have to bring up your
foot and do it. That’s
reaction time.
Average reaction time is about 314 of a second. But
that’s only an average. It might be less with one driver
and as long as two or three seconds or more with
another. Age, physical condition, alertness, coordination
and eyesight all play a part.
So do alcohol, drugs and
frustration. But even in
3/4 of a second, a vehicle
moving at
60 mph (100 km/h) travels 66 feet (20 m).
That could be a lot of distance in an emergency, so
keeping enough space between your vehicle and others
is important.
And, of course, actual stopping distances vary greatly
with the surface of the road (whether it’s pavement or
gravel); the condition
of the road (wet, dry, icy); tire
tread; the condition
of your brakes; the weight of the
vehicle and the amount
of brake force applied.
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Avoid needless heavy braking. Some people drive in
spurts
-- heavy acceleration followed by heavy
braking
-- rather than keeping pace with traffic. This is a
mistake. Your brakes may not have time to cool between
hard stops. Your brakes will wear out much faster if you
do a lot of heavy braking.
If you keep pace with the
traffic and allow realistic following distances, you will
eliminate a lot of unnecessary braking. That means
better braking and longer brake life.
If your engine ever stops while you’re driving, brake
normally but don’t pump your brakes. If you do, the
pedal may get harder to push down.
If your engine
stops, you will still have some power brake assist. But
you will use it when you brake. Once the power assist is
used up, it may take longer to stop and the brake pedal
will be harder to push.
Anti-Lock Brakes (ABS)
your vehicle has anti-lock brakes (ABS). ABS is an
advanced electronic braking system that will help
prevent a braking skid.
When you start your engine and begin to drive away,
your anti-lock brake system will check itself. You may
hear a momentary motor
or clicking noise while this test
is going on. This is normal.
If there’s a problem with the
anti-lock brake system, this
warning light will stay
on.
See “Anti-Lock Brake
System Warning Light”
in ANTI -
LOCK
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Here’s how anti-lock works. Let’s say the road is wet.
You’re driving safely. Suddenly an animal jumps out in
front
of you.
You slam on the brakes. Here’s what happens with ABS.
A computer senses that wheels are slowing down. If one
of the wheels is about to stop rolling, the computer will
separately work the brakes at each front wheel and at the
rear wheels. The anti-lock system can change the brake pressure faster
than any driver could. The computer is programmed to
make
the most of available tire and road conditions.
You can steer around the obstacle while braking hard.
As you brake, your computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.
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Remember: Anti-lock doesn’t change the time you need
to get your foot up
to the brake pedal or always decrease
stopping distance. If you get too close to
the vehicle in
front of
you, you won’t have time to apply your brakes
if that vehicle suddenly slows
or stops. Always leave
enough room up ahead to stop, even though you have
anti-lock brakes.
Using Anti-Lock
Don’t pump the brakes. Just hold the brake pedal down
and let anti-lock work for you. You may feel the brakes
vibrate, or you may notice some noise, but this is normal.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help you more
than even the very best braking.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system
is not functioning, you can steer but
it will take much more effort.
Steering Tips
Driving on Curves
It’s important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here’s why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves. The
traction
of the tires against the road surface makes it
possible for the vehicle to change its path when
you turn
the front wheels. If there’s no traction, inertia
will keep
the vehicle going in the same direction. If you’ve ever
tried to steer a vehicle
on wet ice, you’ll understand this.
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The traction you can get in a curve depends on the
condition
of your tires and the road surface, the angle at
which the curve is banked, and your speed. While you’re
in a curve, speed is the
one factor you can control.
Suppose you’re steering through a sharp curve. Then you
suddenly accelerate.
Both control systems -- steering and
acceleration
-- have to do their work where the tires meet
the road. Adding
the sudden acceleration can demand too
much of those places. You can lose control.
What should you do if this ever happens? Ease up on the
accelerator pedal, steer the vehicle the way you want it
to
go, and slow down.
Speed limit signs near curves warn that
you should
adjust your speed. Of course, the posted speeds are
based on good weather and road conditions. Under less
favorable conditions you’ll want to go slower.
If you need to reduce your speed as you approach a
curve,
do it before you enter the curve, while your front
wheels are straight ahead.
Try to adjust your speed
so you can “drive” through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate until you are out
of the curve, and then
accelerate gently into the straightaway.
Steering in Emergencies
There are times when steering can be more effective
than braking. For example,
you come over a hill and
find
a truck stopped in your lane, or a car suddenly pulls
out from nowhere, or a child darts out from between
parked cars and stops right in front of you. You can
avoid these problems by braking
-- if you can stop
in time. But sometimes you can’t; there isn’t room.
That’s the time for evasive action
-- steering around
the problem.
Your vehicle can perform very well in emergencies like
these. First apply your brakes. (See “Braking in
Emergencies” earlier in this section.) It is better to
remove as much speed as you can from
a possible
collision. Then steer around the problem, to the left or
right depending on the space available.
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0 Check your mirrors, glance over your shoulder and
start your left lane change signal before moving
out
of the right lane to pass. When you are far enough
ahead
of the passed vehicle to see its front in your
inside mirror, activate your right lane change signal
and
move back into the right lane. (Remember that
your right outside mirror is convex. The vehicle you
just passed may seem to be farther away from you
than it really is.)
Try not to pass more than one vehicle at a time on
two-lane roads. Reconsider before passing the
next vehicle.
Don’t overtake a slowly moving vehicle too rapidly.
Even though the brake lamps are not flashing, it may
be slowing down or starting
to turn.
following driver to get ahead
of you. Perhaps you
can ease a little
to the right.
0 If you’re being passed, make it easy for the
Loss of Control
Let’s review what driving experts say about what happens
when the
three control systems (brakes, steering and
acceleration) don’t have enough friction where the tires
meet the road to do what the driver has asked.
In any emergency, don’t give up. Keep trying to steer and
constantly seek an escape route or area of less danger.
Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking reasonable
care suited to existing conditions, and by not “overdriving”
those conditions. But skids are always possible.
The three types
of skids correspond to your vehicle’s
three control systems. In the braking skid, your wheels
aren’t rolling. In the steering or cornering skid, too
much speed or steering in a curve causes tires to slip and
lose cornering force. And
in the acceleration skid, too
much throttle causes the driving wheels to
spin.
A cornering skid and an acceleration skid are best
handled by easing your foot off the accelerator pedal.
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If your vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want the
vehicle to go. If you start steering quickly enough,
your
vehicle may straighten out. Always be ready for a
second skid if it
occurs.
Of course, traction is reduced when water, snow, ice,
gravel or other material is on the road. For safety, you’ll
want to slow down and adjust your driving to these
conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration or
braking (including engine braking by shifting to a lower
gear). Any sudden changes could cause the tires to slide.
You may not realize the surface is slippery until your
vehicle is skidding. Learn to recognize warning
clues
-- such as enough water, ice or packed snow on
the road to make
a “mirrored surface’’ -- and slow
down when you have any doubt.
Remember: Any anti-lock brake system (ABS) helps
avoid only the braking skid.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to be
impaired
-- by alcohol or drugs, with night vision
problems,
or by fatigue.
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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.
A 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.
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Keep your vehicle in good shape. Check all fluid
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.
I A CAUTION:
I
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.
A 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 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. Always have your engine
running and your vehicle in gear when you
go downhill.
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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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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. See “Anti-Lock‘’
in the Index.
Allow greater following distance on any slippery road.
Watch for slippery spots. The road might be fine
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.
If You’re 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 your hazard flashers.
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