1993 GMC SIERRA brakes

c
AM41 501 6
As you brake, your computer keeps receiving updates on rear wheel spee\
d
and controls braking pressure accordingly.
CAUTION I
A
Anti-lock doesn’t change the time you need to get your foot up to I
the brake pedal. 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.
To Use Anti-Lock:
Use rear wheel anti-lock like regular brakes. You may feel the brakes vibrate,
or you may notice some noise outside your vehicle, but this is normal. Let
anti-lock work for you, but remember: Your front wheels can still stop rolling.
If that happens, release enough pressure on the brakes to get the wheels
rolling again
so that you can steer.
With the four-wheel drive option you won’t have anti-lock braking when you
shift into four-wheel drive. But you will have regular braking. When you shift
back into two-wheel drive, you will have anti-lock again.
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Your Driving and fhe Road
Brake System Warning Light
K2325
This light appears on your instrument cluster to warn you if your regular
braking’ system needs service. See “Brake System Warning L\
ight” in the
Index.
Disc Brake Wear Indicators
If you have a C 3500 HD Model, it has four-wheel disc brakes. Disc brake
pads have built-in wear indicators that make a high-pitched war\
ning sound
when the brake pads are worn and new pads are needed. The so\
und m’ay
come and go or be heard all the time your vehicle is moving (except \
when
you are pushing on the brake pedal firmly).
1 CAUTION
The brake wear warning sound means that sooner or later your
hear the brake wear warning sound, have your vehicle serviced. \
5 brakes won’t work well. That could lead to an accident. When you I ~
I 1
i
~ i
brakes are first applied or lightly applied. This does not mea\
n something is
wrong with your brakes.
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Rear Drum Brakes
If you have rear drum brakes, they don’t have the wear indicators, \
but if you
ever hear a rear brake rubbing noise, have the rear brake lining inspected.
Also, the rear brake drums should be removed and inspected each time\
the
tires are removed for rotation or changing. When you have the \
front brakes replaced, have the rear brakes inspected, too.
Brake linings should always be replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return to normal height, or if
there is a rapid increase in pedal travel. This could be a sign of brake
trouble.
Brake Adjusiment
Every time you make a brake stop, your disc brakes adjust for\
wear. If your
brake pedal goes down farther than normal, your rear drum brak\
es may need
adjustment. Adjust them by backing up and firmly applying the brakes a few
times.
Braking In Emergencies
At some time, nearly every driver gets into a situation that requires hard
braking. You have the rear wheel anti-lock braking system. Your front wheels
can stop rolling when you brake very hard. Once they
do, the vehicle can’t
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.
So, use a “squeeze” braking technique. This will give you max\
imum braking
while maintaining steering control. You
do this by pushing on the brake pedal
with steadily increasing pressure. When you
do, it will help maintain steering
control. In many emergencies, steering can help you more than even the very
best braking.
Steering
Power Sieerhg
If you lose power steering assist because the engine stops or \
the system
fails to function, you can steer but it will take much more effort.
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Your Driving and the Road
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 me 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 sudd\
enly apply the
brakes. Both control systems-steering and braking-have to
do their work
where the tires meet the road. Adding the hard braking can de\
mand too
much at those places. You can lose control.
The same thing can happen
if you’re 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.
What should you
do if this ever happens? Let 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’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.
When you drive into a curve at night, it’s harder
to see the road ahead of
you because it bends away from the straight beams
of your lights. This is
one good reason to drive slower.
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Steering in Emergencies
There are times when steering can be more effective than braki\
ng. For example, you come over a hill and find a truck stopped in yo\
ur lane, or a
car suddenly pulls out from nowhere, or a child darts out fro\
m 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; ther\
e 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, but not enough to lock your front wheels. 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 yo\
u
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. You must then be prep\
ared to steer
back to your original lane and then brake to a controlled stop.
Depending on your speed, this can be rather violent for an un\
prepared driver.
This is one of the reasons driving experts recommend that you use your
safety belts and keep both hands on the steering wheel.
K2218
The fact that such emergency situations are always possible is \
a good reason
to practice defensive driving at
all times.
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Your Driving and the Road
the right lane. (Remember that your right outside mirror is c\
onvex. 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.
Don’t overtake a slowly moving vehicle too rapidly. Even though the
Reconsider before passing the next vehicle.
brake lights are not flashing, it may be slowing down
or starting to turn.
If you’re 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’s review what driving experts say about what happens whe\
n the three
control systems (brakes, steering and acceleration) don’t ha\
ve 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 steel+-, arid 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 possib\
le.
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 ea\
sing your
foot
off the accelerator pedal. If your vehicle starts to slide (as when you turn
a corner on a wet, snow-
or ice-covered road), ease your foot off the
accelerator pedal as soon as you feel the vehicle start to sl\
ide. Quickly steer
the way you want the vehicle
to go. If you start steering quickly enough, your
vehicle
will straighten out. As it does, straighten the front wheels.
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 limit\
ed.
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 slid\
e. You
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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: the rear wheel anti-lock braking system (RWAL) helps\
avoid only
a rear braking skid. In a braking skid (where the front wheels are no longer
rolling), release enough pressure on the brakes to get the front wheels rolling
again. This restores steering control. Push the brake pedal dow\
n steadily
when you have to stop suddenly.
As long as the front wheels are rolling, you
will have steering control. Steer the way you want to go.
Off-Road Driving with Your FourcWheel
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, so\
lid surface.
Off-road driving can be great fun. But it does have some defi\
nite 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 a\
re 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. \
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. 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 inflated? Are the fluid levels up where
they should be? What are the local laws that apply to off-roa\
ding 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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Your Driving and the Road
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 dr\
ag 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
A 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 hili?
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 in\
cline 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 N (Neutral), or with the clutch
pedal depressed in a manual shift. This is called “free-whee\
ling,” Your
brakes will have
to do all the work and could overheat and fade.
Avoid braking so hard that you lock the wheels when going downhill. If
your front wheels are locked, you can’t steer your vehicle. \
If your wheels
lock up during downhill braking, you may feel the vehicle star\
ting to slide
sideways.
To regain your direction, just ease off the brakes and steer to
keep the front of the vehicle pointing straight downhill.
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 pa\
rking
brake.
Shift to P (Park) (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.
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