2007 CHEVROLET AVALANCHE brakes

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.
SeeStabiliTrak
®System on page 359.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 433.
Braking
SeeBrake System Warning Light on page 246.
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
Modications on page 433.Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System
(ABS), an advanced electronic braking system that
will help prevent a braking skid.
When you start your engine and begin to drive
away, ABS will check itself. You may hear a
momentary motor or clicking noise while this test
is going on. This is normal.
If there is a problem
with ABS, this warning
light will stay on.
SeeAnti-Lock Brake
System Warning
Light on page 248.
Along with ABS, your vehicle has a Dynamic Rear
Proportioning (DRP) system. If there is a DRP
problem, both the brake and ABS warning lights
will come on accompanied by a 10-second
chime. The lights and chime will come on each
time the ignition is turned on until the problem is
repaired. See your dealer for service.
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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
front wheel and at both rear wheels.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 rmly 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 ABS, you can steer and brake at the same
time. In many emergencies, steering can help
you more than even the very best braking.
Locking Rear Axle
If your vehicle has this feature, it can give you
additional traction on snow, mud, ice, sand
or gravel. It works like a standard axle most of the
time, but when one of the rear wheels has no
traction and the other does, this feature will allow
the wheel with traction to move the vehicle.
StabiliTrak®System
Your vehicle may be equipped with the
StabiliTrak®system which combines antilock
brake, traction and stability control systems and
helps the driver maintain directional control of
the vehicle in most driving conditions.
When you rst start your vehicle and begin to
drive away, the system performs several diagnostic
checks to ensure there are no problems. You
may hear or feel the system working. This
is normal and does not mean there is a problem
with your vehicle. The system should initialize
before the vehicle reaches 20 mph (32 km/h).
In some cases, it may take approximately
two miles of driving before the system initializes.
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Traction Control Operation
The traction control system is part of the
StabiliTrak®system. Traction control limits wheel
spin by reducing engine power to the wheels
(engine speed management) and by applying
brakes to each individual wheel (brake-traction
control) as necessary.
The traction control system is enabled automatically
when you start your vehicle. It will activate and
the StabiliTrak
®light will ash if it senses that any
of the wheels are spinning or beginning to lose
traction while driving. If you turn off traction control,
only the brake-traction control portion of traction
control will work. The engine speed management
will be disabled. In this mode, engine power is not
reduced automatically and the driven wheels can
spin more freely. This can cause the brake-traction
control to activate constantly.
Notice:If you allow the wheel(s) of one axle
to spin excessively while the StabiliTrak
®,
ABS and brake warning lights and the
SERVICE STABILITRAK message are
displayed, you could damage the transfer case.The repairs would not be covered by your
warranty. Reduce engine power and do
not spin the wheel(s) excessively while these
lights and this message are displayed.
The traction control system may activate on dry
or rough roads or under conditions such as
heavy acceleration while turning or abrupt
upshifts/downshifts of the transmission. When
this happens, you may notice a reduction in
acceleration, or may hear a noise or vibration.
This is normal.
If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will ash and
the cruise control will automatically disengage.
When road conditions allow you to use cruise
again, you may re-engage the cruise control.
SeeCruise Control on page 212.
StabiliTrak
®may also turn off automatically if it
determines that a problem exists with the system.
If the problem does not clear itself after restarting
the vehicle, you should see your dealer for
service.
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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
Modications on page 433.
Steering in Emergencies
There are times when steering can be more
effective than braking. For example, you come
over a hill and nd 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 the brakes. SeeBraking
on page 356. 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.An emergency like this requires close attention
and a quick decision. If you are holding the
steering wheel at the recommended 9 and 3 o’clock
positions, you can turn it a full 180 degrees very
quickly without removing either hand. But you
have to act fast, steer quickly, and just as quickly
straighten the wheel once you have avoided
the object.
The fact that such emergency situations are
always possible is a good reason to practice
defensive driving at all times and wear safety
belts properly.
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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,
if 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 ashing, 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.
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 is best handled by easing your
foot off the accelerator pedal.
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Driving Downhill
When off-roading takes you downhill, you will want
to consider a number of things:
How steep is the downhill? Will I be able to
maintain vehicle control?
What is the surface like? Smooth? Rough?
Slippery? Hard-packed dirt? Gravel?
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 the 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.”
The brakes will have to do all the work
and could overheat and fade.
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