1997 GMC SIERRA brakes

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.
On vehicles
with four-wheel drive, your anti-lock brakes
work at all times
-- whether you are in two-wheel drive
or four-wheel drive.
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.
Variable Effort Steering
This system varies the amount of steering effort
proportionate
to your vehicle speed. Steering is easier
at lower speeds for maneuvering and parking ease. As
your vehicle speed increases, the steering effort also
increases.
At highway speeds, the amount of steering
effort is increased for vehicle control and stability.
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.
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.
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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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If other cars are lined up to pass a slow vehicle, wait
your turn. But take care that someone
isn’t 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 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
if
your right outside mirror is convex, the vehicle you
just passed may seem to be farther away from you
than
it really is.)
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 Try not to pass more than one vehicle at a time
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 Guidelines
Off-Road Driving with Your
Four-Wheel-Drive Vehicle
This off-road guide is for vehicles that have
four-wheel drive.
Also, see “Anti-Lock Brakes” in the Index.
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 dnving can be great fun. But
it does have
some definite 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’ll \
find many driving tips and suggestions. These will help
make your off-road driving safer and more enjoyable.
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Driving Downhill
When off-roading takes you downhill, you 11 want to
consider
a number of things:
How steep is the downhill? Will I be able to maintain
What’s the surface like? Smooth? Rough? Slippery?
Are there hidden surface obstacles? Ruts? Logs?
What’s at the bottom of the hill? Is there a hidden
vehicle control?
Hard-packed dirt? Gravel?
Boulders?
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.
I a CAUTIO, .:
0
0
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.
&: Are there some things I should not do when
A: Yes! These are important because if you ignore them
driving down a hill?
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.
Never
go downhill with the transmission in
NEUTRAL
(N), or with the clutch pedal depressed
in a manual shift. This is called “free-wheeling.”
Your brakes will have to do all the work and could
overheat and fade.
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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 (N) 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.
e 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 incl.ine. 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
e
e
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.
Hidden obstacles can make the steepness of
the
incline even worse. If you drive across a rock with
the uphill wheels, or if the downhill wheels drop into
a
rut or depression, your vehicle can tilt even more.
For reasons like these, you need to decide carefully
whether
to try to drive across an incline. Just because the
trail
goes across the incline doesn’t mean you have to
drive it. The last vehicle to
try it might have rolled over.
Driving across an incline that’s too steep will
make your vehicle roll over.
You could be
seriously injured or killed.
If you have any doubt
about the steepness
of the incline, don’t drive
across it. Find another route instead.
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If the water isn’t too deep, then drive through it slowly.
At fast 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.
ki CAU IN:
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 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.
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 fire 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.
See “Driving Through Water”
in the Index for more
information on driving through water.
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