2007 HUMMER H3 engine

Engine Fan Noise
This 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 clutch is not
engaged. This improves fuel economy and reduces
fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the
fan speed increases when the clutch engages.
So you may hear an increase in fan noise.
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.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
disengages.
Power Steering Fluid
SeeEngine
Compartment Overview
on page 322for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power
steering uid unless you suspect there is a leak
in the system or you hear an unusual noise.
A uid loss in this system could indicate a problem.
Have the system inspected and repaired.
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How to Check 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. Then remove the cap again and look at
the uid level on the dipstick.
The level should be between the ADD and FULL
marks. If necessary, add only enough uid to
bring the level up to the proper range.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 440.
Always use the proper uid. Failure to use the
proper uid can cause leaks and damage hoses
and seals.
Windshield Washer Fluid
What to Use
When you need windshield washer uid, be sure
to read the manufacturer’s instructions before
use. If you will be operating your vehicle in an area
where the temperature may fall below freezing,
use a uid that has sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the
washer symbol on it.
Add washer uid
until the tank is full. See
Engine Compartment
Overview on page 322
for reservoir location.
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Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not mix water with ready-to-use washer
uid. Water can cause the solution to
freeze and damage your washer uid tank
and other parts of the washer system.
Also, water does not clean as well
as washer uid.
Fill your washer uid tank only
three-quarters full when it is very cold.
This allows for expansion if freezing
occurs, which could damage the tank if it
is completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
Brakes
Brake Fluid
Your brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 322for the
location of the reservoir.
There are only two reasons why the brake uid
level in the reservoir might go down. The rst
is that the brake uid goes down to an acceptable
level during normal brake lining wear. When
new linings are put in, the uid level goes back
up. The other reason is that uid is leaking out of
the brake system. If it is, you should have your
brake system xed, since a leak means that
sooner or later your brakes will not work well, or
will not work at all.
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So, it is not a good idea to top off your brake uid.
Adding brake uid will not correct a leak. If you
add uid when your linings are worn, then you will
have too much uid when you get new brake
linings. You should add or remove brake uid, as
necessary, only when work is done on the
brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can
spill on the engine. The uid will burn if
the engine is hot enough. You or others
could be burned, and your vehicle could
be damaged. Add brake uid only when
work is done on the brake hydraulic
system. See “Checking Brake Fluid” in
this section.
Refer to the Maintenance Schedule to determine
when to check your brake uid. SeeScheduled
Maintenance on page 429.
Checking Brake Fluid
You can check the brake uid without taking off
the cap.
Look at the brake uid reservoir. The uid level
should be above MIN. If it is not, have your brake
system checked to see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not
over the MAX mark.
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What to Add
When you do need brake uid, use only DOT-3
brake uid. Use new brake uid from a sealed
container only. SeeRecommended Fluids
and Lubricants on page 440.
Always clean the brake uid reservoir cap and the
area around the cap before removing it. This
will help keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in the brake
system, the brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper
brake uid.Notice:
Using the wrong uid can badly damage
brake system parts. For example, just a
few drops of mineral-based oil, such
as engine oil, in the brake system can
damage brake system parts so badly that
they will have to be replaced. Do not
let someone put in the wrong kind of uid.
If you spill brake uid on your vehicle’s
painted surfaces, the paint nish can
be damaged. Be careful not to spill brake
uid on your vehicle. If you do, wash it
off immediately. SeeWashing Your Vehicle
on page 410.
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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. Your vehicle was designed and tested with
top-quality GM brake parts. When you replace parts
of your braking system — for example, when your
brake linings wear down and you need new ones
put in — be sure you get new approved GM
replacement parts. If you do not, your brakes may
no longer work properly. For example, if someone
puts in brake linings that are wrong for your vehicle,
the balance between your front and rear brakes can
change — for the worse. The braking performance
you have come to expect can change in many other
ways if someone puts in the wrong replacement
brake parts.
Battery
Your vehicle has a maintenance free battery.
When it is time for a new battery, get
one that has the replacement number shown on
the original battery’s label. We recommend
an ACDelco
®replacement battery. SeeEngine
Compartment Overview on page 322for
battery location.
Warning: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.
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4. Open the hoods and locate the batteries on
both vehicles. You will use the positive (+)
battery terminal and the remote negative (−)
jump starting terminal to jump start your
vehicle. To access the positive (+) battery
terminal, open the terminal cover. SeeEngine
Compartment Overview on page 322for
more information on the terminal locations.
{CAUTION:
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a ashlight if you need
more light.
CAUTION: (Continued)
CAUTION: (Continued)
Be sure the batteries have enough water.
You do not need to add water to the
ACDelco
®battery (or batteries) installed in
your new vehicle. But if a battery has ller
caps, be sure the right amount of uid is
there. If it is low, add water to take care of
that rst. If you do not, explosive gas
could be present.
Battery uid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on your
skin, ush the place with water and get
medical help immediately.
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{CAUTION:
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
5. Check that the jumper cables do not have
loose or missing insulation. If they do, you
could get a shock. The vehicles could
be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+)
will go to positive (+) or to a remote positive (+)
terminal if the vehicle has one. Negative (−)
will go to a heavy, unpainted metal engine part
or to a remote negative (−) terminal if the
vehicle has one.
Do not connect positive (+) to negative (−)or
you will get a short that would damage
the battery and maybe other parts too. And do
not connect the negative (−) cable to the
negative (−) terminal on the dead battery
because this can cause sparks.6. Connect the red positive (+) cable to the
positive (+) terminal of the dead battery.
Use a remote positive (+) terminal if
the vehicle has one.
7. Do not let the other end touch metal. Connect
it to the positive (+) terminal of the good
battery. Use a remote positive (+) terminal if
the vehicle has one.
8. Now connect the black negative (−) cable to
the negative (−) terminal of the good battery.
Use a remote negative (−) terminal if the
vehicle has one.
Do not let the other end touch anything until
the next step. The other end of the negative (−)
cable does not go to the dead battery. It
goes to a heavy, unpainted metal engine part,
or to a remote negative (−) terminal on the
vehicle with the dead battery.
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