warning HUMMER H3 2010 Owners Manual

Vehicle Care 10-19
Engine Coolant
The cooling system in the vehicle
is filled with DEX-COOL®engine
coolant. This coolant is designed to
remain in the vehicle for five years
or 240 000 km (150,000 miles),
whichever occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating
on
page 10‑22.
What to Use
{WARNING
Adding only plain water to
the cooling system can be
dangerous. Plain water, or some
other liquid such as alcohol,
can boil before the proper
coolant mixture will. The vehicle's
coolant warning system is set
for the proper coolant mixture.
(Continued)
WARNING (Continued)
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL
®coolant.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:
.Gives freezing protection down
to −37°C (−34°F), outside
temperature.
.Gives boiling protection up
to 129°C (265°F), engine
temperature.
.Protects against rust and
corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine
temperature.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.
Notice: If extra inhibitors
and/or additives are used in the
vehicle's cooling system, the
vehicle could be damaged. Use
only the proper mixture of the
engine coolant listed in this
manual for the cooling system.
See Recommended Fluids and
Lubricants
on page 11‑8for more
information.

10-20 Vehicle Care
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
The coolant recovery tank cap has
this symbol on it.
It is located toward the rear of
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview
on
page 10‑6for more information on
location.
Check to see if coolant is visible in
the coolant recovery tank. If the
coolant inside the coolant recovery
tank is boiling, do not do anything
else until it cools down. If coolant is
visible but the coolant level is not at
or above the FULL COLD mark, add
a 50/50 mixture of clean, drinkable water and DEX-COOL coolant at the
coolant recovery tank, but be sure
the cooling system is cool before
this is done.
The vehicle must be on a level
surface. When the engine is cold,
the coolant level should be at FULL
COLD, or a little higher. When the
engine is warm, the level could be
above the FULL COLD level.
When the engine is cold, the coolant
level should be at least up to the
FULL COLD mark. If it is not, there
could be a leak in the cooling
system.
How to Add Coolant to the
Recovery Tank
{WARNING
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
Notice:
This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.
When the coolant in the coolant
recovery tank is at the FULL COLD
mark, start the vehicle.
If coolant is needed, add the proper
DEX-COOL coolant mixture at the
coolant recovery tank.
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.

Vehicle Care 10-21
{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
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. Remove the radiator pressure cap when the cooling system,
including the upper radiator
hose, is no longer hot. Turn
the pressure cap slowly
counterclockwise about
one full turn.
If you hear a hiss, wait for that to
stop. A hiss means there is still
some pressure left.
2. Keep turning the cap to remove it. 3. Fill the radiator with the proper
DEX‐COOL coolant mixture,
up to the base of the filler
neck. See Engine Coolant
on
page 10‑19for more information
about the proper coolant
mixture.
4. Fill the coolant recovery tank to
the FULL COLD mark.
5. Reinstall the cap on the coolant recovery tank, but leave the
radiator pressure cap off.

10-22 Vehicle Care
6. Start the engine and let it rununtil you can feel the upper
radiator hose getting hot. Watch
out for the engine cooling fan.
7. By this time, the coolant level inside the radiator filler neck
might be lower. If the level is
lower, add more of the proper
DEX‐COOL coolant mixture
through the filler neck until the
level reaches the base of the
filler neck.
8. Then replace the pressure cap. 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 an indicator to warn
of engine overheating.
A coolant temperature gauge is
displayed on the instrument panel.
See Engine Coolant Temperature
Gauge on page 5‑9.
You may decide not to lift the
hood when this warning appears,
but instead get service help right
away. See Roadside Service
on
page 13‑5.
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.
The air conditioning might stop
working if the engine is too hot. This
is normal and helps cool the engine.
Notice:
Engine damage from
running the engine without
coolant is not covered by the
warranty.
Notice: If the engine catches
fire because of being driven
with no coolant, your vehicle can
be badly damaged. The costly
repairs would not be covered by
the vehicle warranty.

Vehicle Care 10-23
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. Just 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 your
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop your
engine if it overheats, and get out
of the vehicle until the engine
is cool.
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. See“Driving on
Grades” underTrailer Towingon
page 9‑74.
If the overheat warning is displayed
with no sign of steam:
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. In heavy traffic, let the engine
idle in N (Neutral) while stopped.
If it is safe to do so, pull off
the road, shift to P (Park) or
N (Neutral) and let the
engine idle.
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.

10-26 Vehicle Care
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.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
an accident. 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.

Vehicle Care 10-27
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid as
indicated on the reservoir cap. See
Engine Compartment Overview
on
page 10‑6for 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 5‑14.

10-28 Vehicle Care
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11‑8.
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.Notice:
.Using the wrong fluid
can badly damage brake
hydraulic system parts. For
example, just a few drops of
mineral-based oil, such as
engine oil, in the brake
hydraulic system can
damage brake hydraulic
system parts so badly that
they will have to be replaced.
Do not let someone put in
the wrong kind of fluid.
.If brake fluid is spilled
on the vehicle's painted
surfaces, the paint finish can
be damaged. Be careful not
to spill brake fluid on the
vehicle. If you do, wash it off
immediately.
Battery
Refer to the replacement number
shown on the original battery label
when a new battery is needed. See
Engine Compartment Overview
on
page 10‑6for battery location.
{DANGER
Battery posts, terminals, and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive
harm. Wash hands after handling.

Vehicle Care 10-29
Vehicle Storage
{WARNING
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. SeeJump Starting
on
page 10‑86
for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Four-Wheel Drive
It is recommended that the
four-wheel drive transfer case fluid
be checked and filled by the dealer.
Front Axle
It is not necessary to regularly
check front axle fluid unless a leak
is suspected or an unusual noise is
heard. A fluid loss could indicate a
problem.
It is recommended that the front
axle fluid be checked and filled by
your dealer.
Rear Axle
When to Check and Change
Lubricant
It is not necessary to regularly
check rear axle fluid unless a leak is
suspected or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.
How to Check Lubricant
To get an accurate reading, the
vehicle should be on a level
surface.
A. Rear Axle
B. Filler Plug
The proper level for the rear
axle fluid is 0 mm to 10 mm
(0 to 3/8 inch) below the bottom of
the filler plug hole, located on the
rear axle.
What to Use
See Recommended Fluids and
Lubricantson page 11‑8to
determine which kind of lubricant
to use.

10-30 Vehicle Care
Starter Switch Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular brake.
See Parking Brake
on
page 9‑51.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts. 3. For automatic transmission
vehicles, try to start the engine
in each gear. The vehicle
should start only in P (Park) or
N (Neutral). If the vehicle starts
in any other position, contact
your dealer for service.
For manual transmission
vehicles, put the shift lever in
Neutral, push the clutch pedal
down halfway, and try to start
the engine. The vehicle should
start only when the clutch pedal
is pushed down all the way to
the floor. If the vehicle starts
when the clutch pedal is not
pushed all the way down,
contact your dealer for service.
Automatic Transmission
Shift Lock Control
System Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Firmly apply the parking brake. See Parking Brake
on
page 9‑51.
Be ready to apply the regular
brake immediately if the vehicle
begins to move.