Page 329 of 468

Black plate (17,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Vehicle Care 10-17
How to Add Coolant to the
Radiator
{WARNING
An electric engine cooling fan
under the hood can start up even
when the engine is not running
and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan.
{WARNING
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. They are
under pressure, and if you
turn the surge tank pressure
cap—even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the surge tank
pressure cap, is hot. Wait for the
(Continued)
WARNING (Continued)
cooling system and surge tank
pressure cap to cool if you ever
have to turn the pressure cap.
If coolant is needed, add the proper
mixture directly to the radiator, but
be sure the cooling system is cool
before this is done.
1. Detach the fasteners and lift off the panel that covers the
radiator cap.
2. Remove the radiator pressurecap when the cooling system,
including the upper radiator
hose, is no longer hot.
Turn the pressure cap slowly
counterclockwise about one
full turn.
If a hiss is heard, wait for that
to stop. A hiss means there is
still some pressure left in the
system.
3. Keep turning the pressure cap slowly and remove it.
4. Fill the radiator to the base of the filler neck with the proper
DEX-COOL coolant mixture.
Page 330 of 468

Black plate (18,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-18 Vehicle Care
5. Fill the coolant recovery tank tothe FULL COLD mark.
6. Reinstall the cap on the coolant recovery tank but leave the
radiator pressure cap off.
7. Start the engine and let it run until the upper radiator hose
feels warm. Any time during this
procedure, watch out for the
engine cooling fans. 8. If the coolant level inside the
radiator filler neck is low, add
more of the proper DEX-COOL
coolant mixture through the filler
neck until the level is back up to
the base of the filler neck.
9. Replace the pressure cap. Be sure to secure it tightly.
At any time during this
procedure if coolant begins
to flow out of the filler neck,
reinstall the pressure cap.
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
The vehicle has several indicators
to warn of engine overheating.
There is an engine coolant
temperature gauge on the
instrument panel cluster.
See Engine Coolant Temperature
Gauge on page 5‑14.
The vehicle may also display
an ENGINE OVERHEATED
IDLE ENGINE and ENGINE
OVERHEATED STOP ENGINE
message in the Driver Information
Center (DIC). See Engine Cooling
System Messages on page 5‑39.
You may decide not to lift the hood
when this warning appears, but
instead get service help right away.
See Roadside Assistance Program
(U.S. and Canada) on page 13‑8
or Roadside Assistance Program
(Mexico) on page 13‑10.
Page 331 of 468

Black plate (19,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Vehicle Care 10-19
If you do decide 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 the engine without
coolant is not covered by the
warranty.
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 10‑20 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.
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.
(Continued)
WARNING (Continued)
SeeOverheated Engine
Protection Operating Mode on
page 10‑20 for information on
driving to a safe place in an
emergency.
If No Steam Is Coming from
the Engine Compartment
If an engine overheat warning is
displayed but no steam can be 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
Page 332 of 468

Black plate (20,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-20 Vehicle Care
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highesttemperature and to the highest
fan speed. Open the windows as
necessary.
3. If in a traffic jam, shift to N (Neutral); otherwise,
shift to the highest gear while
driving —D (Drive) or L (Low).
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 slow
for about 10 minutes. Keep a safe
vehicle distance from the car in front
of you. 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 three minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
next in this section.
Overheated Engine
Protection
Operating Mode
This emergency operating mode lets
the vehicle be driven to a safe place
in an emergency situation. If an
overheated engine condition exists,
an overheat protection mode which
alternates firing groups of cylinders
helps prevent engine damage. In this mode, there is a significant
loss in power and engine
performance. The temperature
gauge indicates an overheat
condition exists. Driving extended
distances 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 10‑8.
Page 333 of 468

Black plate (21,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Vehicle Care 10-21
Power Steering Fluid
The power steering fluid reservoir is
located under the engine cover on
the passenger side of the vehicle.
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
you suspect there is a leak in the
system or you hear an unusual
noise. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power
Steering Fluid
Notice:Extremely small amounts
of contamination can cause
steering system damage and
cause it to not work properly.
Do not allow contaminants to
contact the fluid side of the
reservoir cap/dipstick or to
enter the reservoir.
To check the power steering fluid:
1. Turn the key off and let the engine compartment cool down.
2. Remove the engine cover. See Engine Cover on page 10‑8.
3. Wipe the cap and the top of the reservoir clean.
4. Unscrew the cap and wipe the dipstick with a clean rag.
5. Replace the cap and completely tighten it.
6. Remove the cap again and look at the fluid level on the dipstick. The fluid level should be
somewhere between the MAX and
MIN line on the dipstick in room
temperature. If the fluid is on or
below the MIN line, add fluid close
to the MAX Line.
What to Use
To determine what kind of fluid to
use, see
Recommended Fluids and
Lubricants on page 11‑12. 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 11‑12.
Page 334 of 468

Black plate (22,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-22 Vehicle Care
Washer Fluid
What to Use
When adding windshield
washer fluid, be sure to read the
manufacturer's instructions before
use. If the vehicle will be operating
in an area where the temperature
may fall below freezing, use a fluid
that has sufficient protection against
freezing.
Adding Washer Fluid
When the windshield washer fluid
reservoir is low, a WASHER FLUID
LOW ADD FLUID message will be
displayed on the Driver Information
Center (DIC). SeeWasher Fluid
Messages on page 5‑45 for more
information.
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
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 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.
Page 335 of 468

Black plate (23,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Vehicle Care 10-23
{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.
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 in
Capacities and
Specifications on page 12‑2.
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.
Page 336 of 468

Black plate (24,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-24 Vehicle Care
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid as
indicated on the reservoir cap.
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,
and the vehicle could be
damaged. Add brake fluid only
when work is done on the brake
hydraulic system. When the brake fluid falls to a low
level, the brake warning light comes
on. See
Brake System Warning
Light on page 5‑21.
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11‑12.
Always clean the brake fluid
reservoir cap and the area
around the cap before removing it.
This helps keep dirt from entering
the reservoir.{WARNING
With the wrong kind of fluid in
the brake hydraulic system, the
brakes might not work well.
This could cause a crash.
Always use the proper brake fluid.