2011 GMC SIERRA Owner's Manual

Black plate (25,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-25
3. Fill the coolant surge tankwith the proper mixture to the
FULL COLD mark.
4. With the coolant surge tank pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90°C (195°F). By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
FULL COLD mark.
5. Replace the pressure cap. Be sure the pressure cap is
hand-tight and fully seated.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 through 6.
Notice: If the pressure cap is
not tightly installed, coolant loss
and possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
If the vehicle has the Duramax®
Diesel engine, see the Duramax
Diesel Supplement for more
information.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on the vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑17.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC) on the
instrument panel. See Engine
Cooling System Messages on
page 5‑44 andEngine Power
Messages on page 5‑45.

Black plate (26,1)GMC Sierra Owner Manual - 2011
10-26 Vehicle Care
If the decision is made not to lift the
hood when this warning appears,
get service help right away.
SeeRoadside Assistance Program
(U.S. and Canada) on page 13‑8
or Roadside Assistance Program
(Mexico) on page 13‑10.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Then check to see if the engine
cooling fans are running. If the
engine is overheating, both fans
should be running. If they are not,
do not continue to run the engine
and have the vehicle serviced.
Notice: Engine damage from
running your engine without
coolant is not covered by the
vehicle warranty. See Overheated
Engine Protection Operating
Mode for information on driving
to a safe place in an emergency. Notice:
If the engine catches fire
while driving with no coolant, the
vehicle can be badly damaged.
The costly repairs would not
be covered by the vehicle
warranty. See Overheated Engine
Protection Operating Mode on
page 10‑28 for information on
driving to a safe place in an
emergency.
If Steam is Coming from the
Engine Compartment
{WARNING
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or
hear steam coming from it.
Turn it off and get everyone
away from the vehicle until it
cools down. Wait until there
is no sign of steam or coolant
before you open the hood.
(Continued)
WARNING (Continued)
If you keep driving when the
vehicles engine is overheated,
the liquids in it can catch fire.
You or others could be badly
burned. Stop the engine if it
overheats, and get out of the
vehicle until the engine is cool.
SeeOverheated Engine
Protection Operating Mode on
page 10‑28 for information on
driving to a safe place in an
emergency.

Black plate (27,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-27
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.
If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.Climbs a long hill on a hot day
.Stops after high-speed driving
.Idles for long periods in traffic
.Tows a trailer; seeTrailer Towing
on page 9‑95. If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so:
1. Turn the air conditioning off.
2. Turn the heater on to the highest
temperature and to the highest
fan speed. Open the windows
as necessary.
3. If stopped in a traffic jam, apply the brake, shift to N (Neutral);
otherwise, shift to the highest
gear while driving —D (Drive)
or 3 (Third).
If the temperature overheat gauge
is no longer in the overheat zone
or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally.
If the warning continues, pull
over, stop, and park the vehicle
right away.
If there is no sign of steam, idle
the engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
later in this section.

Black plate (28,1)GMC Sierra Owner Manual - 2011
10-28 Vehicle Care
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage.
In this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe
place in an emergency. Driving
extended km (mi) and/or towing a
trailer in the overheat protection
mode should be avoided.
Notice:After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause
of coolant loss, change the oil
and reset the oil life system.
See Engine Oil on page 10‑7.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and
the clutch is not fully engaged.
This improves fuel economy and
reduces fan noise. Under heavy
vehicle loading, trailer towing,
and/or high outside temperatures,
the fan speed increases as the
clutch more fully engages, so an
increase in fan noise may be heard.
This is normal and should not be
mistaken as the transmission
slipping or making extra shifts.
It is merely the cooling system
functioning properly. The fan will
slow down when additional cooling
is not required and the clutch
disengages. This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during
most everyday driving. The fans
may turn off if no cooling is required.
Under heavy vehicle loading, trailer
towing, high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly.
The fans will change to low speed
when additional cooling is no
longer required.

Black plate (29,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-29
Power Steering Fluid
SeeEngine Compartment Overview
on page 10‑6 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.
The level should be at the
FULL COLD mark. If necessary,
add only enough fluid to bring the
level up to the mark.
What to Use
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants on page 11‑8. Always
use the proper fluid.
Notice: Use of the incorrect fluid
may damage the vehicle and the
damages may not be covered by
the vehicle's warranty. Always
use the correct fluid listed in
Recommended Fluids and
Lubricants on page 11‑8.
Washer Fluid
What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient
protection against freezing in an
area where the temperature may
fall below freezing.

Black plate (30,1)GMC Sierra Owner Manual - 2011
10-30 Vehicle Care
Adding Washer Fluid
The vehicle has a low washer fluid
message on the DIC that comes
on when the washer fluid is low.
The message is displayed for
15 seconds at the start of each
ignition cycle. When the WASHER
FLUID LOW ADD FLUID message
displays, washer fluid will need to
be added to the windshield washer
fluid reservoir.
Open the cap with the washer
symbol on it. Add washer fluid
until the tank is full. SeeEngine
Compartment Overview on
page 10‑6 for reservoir location. Notice:
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
Also, water does not clean
as well as washer fluid.
.Fill the washer fluid tank
only three-quarters full
when it is very cold. This
allows for fluid expansion
if freezing occurs, which
could damage the tank if
it is completely full.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.
Brakes
This vehicle has front disc brakes
and could have rear drum brakes or
rear disc brakes.
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or
be heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair.

Black plate (31,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-31
Some driving conditions or climates
can cause a brake squeal when
the brakes are first applied or
lightly applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in
the proper sequence to torque
specifications inCapacities and
Specifications on page 12‑2.
If the vehicle has rear drum brakes,
they do not have wear indicators,
but if a rear brake rubbing noise is
heard, have the rear brake linings
inspected immediately. Rear brake
drums should be removed and
inspected each time the tires are
removed for rotation or changing. Drum brakes have an inspection
hole to inspect lining wear during
scheduled maintenance. When
the front brake pads are 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 that brake service might
be required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that
are wrong for the vehicle, can
change the balance between the
front and rear brakes
—for the
worse. The braking performance
expected can change in many
other ways if the wrong replacement
brake parts are installed.

Black plate (32,1)GMC Sierra Owner Manual - 2011
10-32 Vehicle Care
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid.
SeeEngine Compartment Overview
on page 10‑6 for the location of the
reservoir.
There are only two reasons why
the brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also
cause a low fluid level. Have
the brake hydraulic system fixed,
since a leak means that sooner
or later the brakes will not
work well.
Do not top off the brake fluid.
Adding fluid does not correct a
leak. If fluid is added when the
linings are worn, there will be too
much fluid when new brake linings
are installed. Add or remove brake
fluid, as necessary, only when work
is done on the brake hydraulic
system.
{WARNING
If too much brake fluid is added,
it can spill on the engine and
burn, if the engine is hot enough.
You or others could be burned, (Continued)
WARNING (Continued)
and the vehicle could be
damaged. Add brake fluid only
when work is done on the brake
hydraulic system. See “Checking
Brake Fluid” in this section.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5‑27.
Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See Scheduled
Maintenance on page 11‑2.