1998 GMC ENVOY brake

Brake System Warning Light
When the ignition is on, the brake system warning light
will come on when you set your parking brake. The light
will stay on
if your parking brake doesn’t release fully.
If it stays on after your parking brake is fully released, it
means you have a brake problem.
If the light comes on while you are driving, pull off the
road and stop carefully.
You may notice that the pedal is
harder to push.
Or, the pedal may go closer to the floor.
It may take longer to stop.
If the light is still on, have the
vehicle towed for service. (See “Towing Your Vehicle”
in the Index.)
Your vehicle’s hydraulic brake system is divided into
two parts.
If one part isn’t working, the other part can
still work and stop you. For good braking, though, you
need both parts working well.
If the warning light comes on, there could be a brake
problem. Have your brake system inspected right away.
This light should come
on
briefly when you turn the
ignition key to
RUN. If it
it fixed so it will be ready
to warn you if there’s
a problem.
(0) (8> doesn’t come on then, have
BRAKE
Your brake system may not be working properly
if the brake system warning light is on. Driving
with the brake system warning light on can lead
to an accident.
If the light is still on after you’ve
pulled off the road and stopped carefully, have
the vehicle towed for service.
2-65
1
ProCarManuals.com

Anti-Lock Brake System Warning Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay
on
for several seconds.
That’s normal.
If the light stays on, or comes on when you’re driving,
your vehicle needs service. If the regular brake system
warning light isn’t on,
you still have brakes, but you
don’t have anti-lock brakes. If the regular brake system
warning light is
also on, you don’t have anti-lock brakes
and there’s a problem with your regular brakes. See
“Brake System Warning Light” earlier
in this section.
The anti-lock brake system warning light should come
on briefly when you turn the ignition key to RUN. If the
light doesn’t come on then, have it fixed
so it will be
ready to warn you
if there is a problem.
Engine Coolant Temperature Gage
This gage shows the engine
coolant temperature. If the
gage pointer moves into
the
red area, your engine is
too hot!
It means that your engine coolant has overheated. If you
have been operating your vehicle under normal driving
conditions,
you should pull off the road, stop your
vehicle and turn off
the engine as soon as possible.
The “Problems on the Road” section
of this manual
shows you what to do. See “Engine Overheating”
in
the Index.
2-66
ProCarManuals.com

Defensive Driving
The best advice anyone can give about driving is:
Drive defensively.
Please start
with a very important safety device in your
vehicle: Buckle up. (See "Safety Belts"
in the Index.) Defensive driving really means
"be ready for anything."
On city streets, rural roads or freeways,
it means
"always expect the unexpected."
Assume that pedestrians or other drivers are going to be
careless and make mistakes. Anticipate what they might
do. Be ready for their mistakes.
Rear-end collisions are about the most preventable of
accidents. Yet they are common. Allow enough
following distance.
It's the best defensive driving
maneuver.
in both city and rural driving. You never
know when the vehicle
in front of you is going to brake
or
turn suddenly.
Defensive driving requires that a driver concentrate
on
the driving task. Anything that distracts from the driving
task
-- such as concentrating on a cellular telephone
call, reading, or reaching for something on the
floor
-- makes proper defensive driving more difficult
and can even cause a collision, with resulting injury.
Ask a passenger to help do things like this, or pull off
the road
in a safe place to do them yourself. These
simple defensive driving techniques could save
your life.
ProCarManuals.com

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.
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
i
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.
!
I
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.
4-6 I
ProCarManuals.com

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.
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 rnucit 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. Th, ti t 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
;1 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
the Index.
4-7
1
ProCarManuals.com

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
both 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.
4-8
ProCarManuals.com

Re,member: 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.
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.
Using Anti-Lock
Don‘t pump the brakes. Just hold the brake pedal down
firmly and let anti-lock work for you. You may feel the
brakes vibrate,
or YOLI may notice some noise, but
this is normal. Your anti-lock brakes work at all
times
-- whether you are in two-wheel 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 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.
4-9
1
ProCarManuals.com

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
YOLK 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
the.ir 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 YOLI can from a possible
collision. Then steer around the problem, to
the left or
right depending on the space available.
4-10
ProCarManuals.com