brake CHEVROLET OPTRA 5 2007 1.G 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 are driving on snow or
ice, it is easy to ask more of those control systems
than the tires and road can provide. That means
you can lose control of your vehicle.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modifications on page 249.
Braking
SeeBrake System Warning Light on page 168.
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake
pedal. That is perception time. Then you have to
bring up your foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is 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 three-fourths 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 is
pavement or gravel; the condition of the road,
whether it is wet, dry, or icy; tire tread; the
condition of the 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. The brakes may not have
time to cool between hard stops. The 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 vehicle’s engine ever stops while you are
driving, brake normally but do not pump the
brakes. If you do, the pedal may get harder to
push down. If the 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.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modifications on page 249.Anti-Lock Brake System (ABS)
Your vehicle may have the Anti-Lock Brake
System (ABS), an advanced electronic braking
system that will help prevent a braking skid.
If your vehicle has ABS,
this warning light on the
instrument panel will
come on briefly
when you start your
vehicle.
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Let us say the road is wet and you are driving
safely. Suddenly, an animal jumps out in front of
you. You slam on the brakes and continue braking.
Here is 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 wheel.ABS can change the brake pressure faster than
any driver could. The computer is programmed
to make the most of available tire and road
conditions. This can help you 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: ABS does not 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 will not
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 ABS.
Using ABS
Do not pump the brakes. Just hold the brake
pedal down firmly and let anti-lock work for you.
You may feel a slight brake pedal pulsation
or notice some noise, but this is normal.
Braking in Emergencies
At some time, nearly every driver gets into a
situation that requires hard braking.
If you have ABS, you can steer and brake at the
same time. However, if you do not have ABS, your
first reaction — to hit the brake pedal hard and
hold it down — may be the wrong thing to do.Your wheels can stop rolling. Once they do, the
vehicle cannot respond to your steering.
Momentum will carry it in whatever direction it was
headed when the wheels stopped rolling. That
could be off the road, into the very thing you were
trying to avoid, or into traffic.
If you do not have ABS, use a “squeeze” braking
technique. This will give you maximum braking
while maintaining steering control. You can do this
by pushing on the brake pedal with steadily
increasing pressure.
In an emergency, you will probably want to
squeeze the brakes hard without locking the
wheels. If you hear or feel the wheels sliding,
ease off the brake pedal. This will help you
retain steering control. If you do have ABS, it is
different. SeeAnti-Lock Brake System (ABS)
on page 211.
In many emergencies, steering can help you more
than even the very best braking.
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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.
Speed Sensitive Power Steering (SSPS)
If your vehicle has this optional steering system,
the steering system continuously adjusts the effort
you feel when steering at all vehicle speeds.
It provides ease when parking, yet a firm, solid
feel at highway speeds.
Steering Tips
It is important to take curves at a reasonable
speed.
A lot of the “driver lost control” accidents
mentioned on the news happen on curves.
Here is 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 is no traction, inertia will keep the vehicle
going in the same direction. If you have ever
tried to steer a vehicle on wet ice, you will
understand this.
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 are in a curve, speed is the
one factor you can control.
Suppose you are steering through a sharp curve.
Then you suddenly apply the brakes. Both
control systems — steering and braking — have
to do their work where the tires meet the road.
Unless you have four-wheel anti-lock brakes,
adding the hard braking can demand too much of
those places. You can lose control.
The same thing can happen if you are steering
through a sharp curve and you suddenly
accelerate. Those two control systems — steering
and acceleration — can overwhelm those
places where the tires meet the road and make
you lose control.
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What should you do if this ever happens? Ease up
on the brake or 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 will
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.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modifications on page 249.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 cannot; there is not room.
That is the time for evasive action — steering
around the problem.
Your vehicle can perform very well in emergencies
like these. First apply your brakes — but, unless
you have anti-lock brakes, not enough to lock your
wheels.
SeeBraking on page 210. 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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•When it looks like a chance to pass is coming
up, start to accelerate but stay in the right
lane and do not get too close. Time your move
so you will be increasing speed as the time
comes to move into the other lane. If the way
is clear to pass, you will have a running
start that more than makes up for the distance
you would lose by dropping back. And if
something happens to cause you to cancel
your pass, you need only slow down and drop
back again and wait for another opportunity.
•If other vehicles are lined up to pass a slow
vehicle, wait your turn. But take care that
someone is not trying to pass you as you pull
out to pass the slow vehicle. Remember to
glance over your shoulder and check the
blind spot.
•Check your vehicle’s 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 vehicle’s inside mirror, activate the right
lane change signal and move back into
the right lane. Remember that your vehicle’s
passenger side 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.
•Do not overtake a slowly moving vehicle too
rapidly. Even though the brake lamps are
not flashing, it may be slowing down or starting
to turn.
•If you are being passed, make it easy for the
following driver to get ahead of you. Perhaps
you can ease a little to the right.
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Loss of Control
Let us review what driving experts say about what
happens when the three control systems — brakes,
steering, and acceleration — do not have enough
friction where the tires meet the road to do what the
driver has asked.
In any emergency, do not 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 are not 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.
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 will 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.
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While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration, or
braking, including reducing vehicle speed 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.
If you have the Anti-Lock Brake System (ABS),
remember: It helps avoid only the braking
skid. If you do not have ABS, then in a braking
skid, where the wheels are no longer rolling,
release enough pressure on the brakes to get the
wheels rolling again. This restores steering
control. Push the brake pedal down steadily when
you have to stop suddenly. As long as the
wheels are rolling, you will have steering control.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.
Here are some tips on night driving.
•Drive defensively.
•Do not drink and drive.
•Adjust the inside rearview mirror to reduce the
glare from headlamps behind you.
•Since you cannot see as well, you may need
to slow down and keep more space between
you and other vehicles.
•Slow down, especially on higher speed roads.
Your vehicle’s headlamps can light up only so
much road ahead.
•In remote areas, watch for animals.
•If you are tired, pull off the road in a safe
place and rest.
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{CAUTION:
Wet brakes can cause accidents. They
may not 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 the brake pedal
lightly until the brakes work normally.
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 cannot, try
to slow down before you hit them.
Hydroplaning
Hydroplaning is dangerous. So much water can
build up under your tires that they can 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.
Hydroplaning does not happen often. But it can if
your tires do not have much tread or if the
pressure in one or more is low. It can happen if a
lot of water is standing on the road. If you can
see reflections from trees, telephone poles,
or other vehicles, and raindrops dimple the water’s
surface, there could be hydroplaning.
Hydroplaning usually happens at higher speeds.
There just is not a hard and fast rule about
hydroplaning. The best advice is to slow down
when it is raining.
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