brakes GMC SIERRA 2011 User Guide

Black plate (3,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-3
Death and injury associated with
drinking and driving is a global
tragedy.
Alcohol affects four things that
anyone needs to drive a vehicle:
judgment, muscular coordination,
vision, and attentiveness.
Police records show that
almost 40 percent of all motor
vehicle-related deaths involve
alcohol. In most cases, these
deaths are the result of someone
who was drinking and driving.
In recent years, more than
17,000 annual motor vehicle-related
deaths have been associated with
the use of alcohol, with about
250,000 people injured.
For persons under 21, it is against
the law in every U.S. state to drink
alcohol. There are good medical,
psychological, and developmental
reasons for these laws.
The obvious way to eliminate the
leading highway safety problem is
for people never to drink alcohol
and then drive.Medical research shows that
alcohol in a person's system
can make crash injuries worse,
especially injuries to the brain,
spinal cord, or heart. This means
that when anyone who has been
drinking
—driver or passenger —is
in a crash, that person's chance of
being killed or permanently disabled
is higher than if the person had not
been drinking.
Control of a Vehicle
The following three systems
help to control the vehicle while
driving —brakes, steering, and
accelerator. At times, as when
driving on snow or ice, it is easy to
ask more of those control systems
than the tires and road can provide.
Meaning, you can lose control of the
vehicle. See StabiliTrak
®System on
page 9‑70.
Adding non‐dealer accessories
can affect vehicle performance.
See Accessories and Modifications
on page 10‑3.
Braking
See Brake System Warning Light on
page 5‑27.
Braking action involves perception
time and reaction time. Deciding
to push the brake pedal is
perception time. Actually doing
it 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 100 km/h
(60 mph) travels 20 m (66 ft).
That could be a lot of distance in
an emergency, so keeping enough
space between the vehicle and
others is important.

Black plate (4,1)GMC Sierra Owner Manual - 2011
9-4 Driving and Operating
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.
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
might not have time to cool between
hard stops. The brakes will wear
out much faster with a lot of heavy
braking. Keeping pace with the
traffic and allowing realistic following
distances eliminates a lot of
unnecessary braking. That means
better braking and longer brake life.
If the engine ever stops while the
vehicle is being driven, brake
normally but do not pump the brakes. If the brakes are pumped,
the pedal could get harder to push
down. If the engine stops, there will
still be some power brake assist but
it will be used when the brake is
applied. Once the power assist is
used up, it can take longer to stop
and the brake pedal will be harder
to push.
Adding non‐dealer accessories
can affect vehicle performance.
See
Accessories and Modifications
on page 10‑3.
Steering
Power Steering
If the vehicle is a hybrid, see
the hybrid supplement for more
information.
If power steering assist is lost
because the engine stops or the
power steering system is not
functioning, the vehicle can be
steered but it will take more effort.
Steering Tips
It is important to take curves at a
reasonable speed.
Traction in a curve depends on the
condition of the tires and the road
surface, the angle at which the
curve is banked, and vehicle speed.
While in a curve, speed is the one
factor that can be controlled.
If there is a need to reduce speed,
do it before entering the curve, while
the front wheels are straight.
Try to adjust the speed so you can
drive through the curve. Maintain a
reasonable, steady speed. Wait to
accelerate until out of the curve,
and then accelerate gently into
the straightaway.

Black plate (5,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-5
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. These problems
can be avoided by braking—if you
can stop in time. But sometimes you
cannot stop in time because there
is no room. That is the time for
evasive action —steering around
the problem.
The vehicle can perform very
well in emergencies like these.
First, apply the brakes. See Braking
on page 9‑3. It is better to remove
as much speed as possible from
a 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 holding the steering wheel at
the recommended 9 and 3 o'clock
positions, it can be turned 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.
Off-Road Recovery
The vehicle's right wheels can drop
off the edge of a road onto the
shoulder while driving.
If the level of the shoulder is
only slightly below the pavement,
recovery should be fairly easy. Ease
off the accelerator and then, if there
is nothing in the way, steer so that
the vehicle straddles the edge of
the pavement. Turn the steering
wheel 8 to 13 cm (3 to 5 in), about
one-eighth turn, until the right front
tire contacts the pavement edge.
Then turn the steering wheel to
go straight down the roadway.

Black plate (6,1)GMC Sierra Owner Manual - 2011
9-6 Driving and Operating
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 the vehicle's three control
systems. In the braking skid,
the 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.
If the 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, the 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,
slow down and adjust your driving to
these conditions. It is important to
slow down on slippery surfaces
because stopping distance is longer
and vehicle control more limited.
While driving on a surface with
reduced traction, try 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 might
not realize the surface is slippery
until the 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: Antilock brakes help
avoid only the braking skid.

Black plate (15,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-15
Driving Downhill
When off-roading takes you
downhill, consider:
.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, try to keep the vehicle
headed straight down. Use a low
gear so engine drag can help the
brakes so they do not have to do all
the work. Descend slowly, keeping
the vehicle under control at all
times.
{WARNING
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.
Things not to do when driving down
a hill:
.When driving downhill, avoid
turns that take you across the
incline of the hill. A hill that is
not too steep to drive down
might be too steep to drive
across. The vehicle could
roll over.
.Never go downhill with the
transmission in N (Neutral),
called free-wheeling. The brakes
will have to do all the work and
could overheat and fade.
Vehicles are much more likely to
stall when going uphill, but if it
happens when going downhill:
1. Stop the vehicle by applying the regular brakes and apply the
parking brake.
2. Shift to P (Park) and, while still braking, restart the engine.
3. Shift back to a low gear, release the parking brake, and drive
straight down.
4. If the engine will not start, get out and get help.

Black plate (18,1)GMC Sierra Owner Manual - 2011
9-18 Driving and Operating
Driving in Water
{WARNING
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires, and
you could lose traction and roll
the vehicle over. Do not drive
through rushing water.
Heavy rain can mean flash flooding,
and flood waters demand extreme
caution. Find out how deep the water is
before driving through it. Do not
try it if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe
—you probably will not get
through. Deep water can damage
the axle and other vehicle parts.
If the water is not too deep, drive
slowly through it. At faster speeds,
water splashes on the ignition
system and the vehicle can stall.
Stalling can also occur if you get the
tailpipe under water. If the tailpipe is
under water, you will never be able
to start the engine. When going
through water, remember that when
the brakes get wet, it might take
longer to stop. See Driving on Wet
Roads on page 9‑19.
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 and
check the fuel lines and cooling
system for any leakage.
The vehicle requires more frequent
service due to off-road use. Refer
to the Maintenance Schedule for
additional information.

Black plate (19,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-19
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep‐standing or flowing water.
{WARNING
Wet brakes can cause crashes.
They might not work as well in
a quick stop and could cause
pulling to one side. You could
lose control of the vehicle.(Continued)
WARNING (Continued)
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to
drive through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road
is wet enough and you are going
fast enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.

Black plate (20,1)GMC Sierra Owner Manual - 2011
9-20 Driving and Operating
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping
equipment in good shape.
.Keep the windshield washer fluid
reservoir filled.
.Have good tires with proper
tread depth. SeeTires on
page 10‑57.
.Turn off cruise control.
Highway Hypnosis
Always be alert and pay attention
to your surroundings while driving.
If you become tired or sleepy, find
a safe place to park the vehicle
and rest.
Other driving tips include:
.Keep the vehicle well ventilated.
.Keep interior temperature cool.
.Keep your eyes moving —scan
the road ahead and to the sides.
.Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{WARNING
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.

Black plate (21,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-21
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will
have to do all the work of slowing
down and they could get so hot
that they would not work well.
You would then have poor braking
or even none going down a hill.
You could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in
your own lane.
.Top of hills: Be alert—
something could be in your
lane (stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 0°C
(32°F) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick, so there is even less
traction. Try not to break the fragile traction.
If you accelerate too fast, the drive
wheels will spin and polish the
surface under the tires even more.
The
Antilock Brake System (ABS)
on page 9‑68 improves vehicle
stability during hard stops on
slippery roads, but apply the brakes
sooner than when on dry pavement.
Allow greater following distance on
any slippery road and watch for
slippery spots. Icy patches can
occur on otherwise clear roads in
shaded areas. The surface of a
curve or an overpass can remain
icy when the surrounding roads
are clear. Avoid sudden steering
maneuvers and braking while
on ice.
Turn off cruise control on slippery
surfaces.

Black plate (36,1)GMC Sierra Owner Manual - 2011
9-36 Driving and Operating
A (STOPPING THE ENGINE/
LOCK/OFF):When the vehicle is
stopped, turn the ignition switch to
LOCK/OFF to turn the engine off.
Retained Accessory Power (RAP)
will remain active. See Retained
Accessory Power (RAP) on
page 9‑40.
This position locks the ignition.
It also locks the transmission on
automatic transmission vehicles.
The key can be removed in
LOCK/OFF.
Do not turn the engine off when the
vehicle is moving. This will cause a
loss of power assist in the brake
and steering systems and disable
the airbags. In an emergency:
1. Brake using a firm and steady
pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to neutral. This can be done while the vehicle is
moving. After shifting to neutral,
firmly apply the brakes and steer
the vehicle to a safe location.
3. Come to a complete stop, shift to P (Park), and turn the ignition
to LOCK/OFF. On vehicles with
an automatic transmission, the
shift lever must be in P (Park)
to turn the ignition switch to the
LOCK/OFF position.
4. Set the parking brake. See Parking Brake on page 9‑69. The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
doesn't work, then the vehicle
needs service.
Notice:
Using a tool to force the
key to turn in the ignition could
cause damage to the switch or
break the key. Use the correct
key, make sure it is all the way in,
and turn it only with your hand.
If the key cannot be turned by
hand, see your dealer.
B (ACC/ACCESSORY): This
position lets things like the radio
and the windshield wipers operate
while the engine is off. Use this
position if the vehicle must be
pushed or towed.