4 WHEEL DRIVE HUMMER H3 2007 Service Manual

Dinghy Towing
Use the following procedure to tow your vehicle:
1. Shift the transmission to NEUTRAL (N).
2. Turn the engine off, but leave the
ignition in ON.
3. Firmly set the parking brake.
4. Securely attach the vehicle being towed to
the tow vehicle.
{CAUTION:
Shifting a full-time four-wheel-drive
vehicle’s transfer case into NEUTRAL
can cause your vehicle to roll even if the
automatic transmission is in PARK (P) or
the manual transmission is in any gear.
You or others could be injured. Make sure
the parking brake is rmly set before
you shift the transfer case to NEUTRAL.5. Shift the transfer case to NEUTRAL (N). See
Full-Time Four-Wheel Drive on page 111for
the proper procedure to select the NEUTRAL
position for your vehicle.
6. Put the transmission in PARK (P) for an
automatic transmission or in FIRST (1) for
a manual transmission.
7. Release the parking brake only after the
vehicle being towed is rmly attached to
the towing vehicle.
8. Turn the ignition off.
After towing, see “Shifting Out of NEUTRAL”
underFull-Time Four-Wheel Drive on page 111.
Dolly Towing
Notice:Dolly towing your vehicle will damage
drivetrain components. Do not dolly tow
your vehicle.
Your vehicle cannot be dolly towed. If you must
tow your vehicle behind another, use the
dinghy towing procedure listed previously.
296

Parking on Hills
{CAUTION:
You really should not park your
vehicle, with a trailer attached, on a hill.
If something goes wrong, your rig could
start to move. People can be injured,
and both your vehicle and the trailer can
be damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet for an automatic transmission,
or into gear for a manual transmission.
Turn your wheels into the curb if facing
downhill or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.3. When the wheel chocks are in place, release
the regular brakes until the chocks absorb
the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P) for an
automatic transmission or into gear for a
manual transmission.
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of
the chocks.
4. Stop and have someone pick up and store
the chocks.
306

Service........................................................ 314
Accessories and Modications................... 314
California Proposition 65 Warning.............. 315
Doing Your Own Service Work.................. 315
Adding Equipment to the Outside
of Your Vehicle...................................... 316
Fuel............................................................. 316
Gasoline Octane........................................ 316
Gasoline Specications.............................. 316
California Fuel........................................... 316
Additives................................................... 317
Fuels in Foreign Countries........................ 318
Filling the Tank......................................... 318
Filling a Portable Fuel Container............... 320
Checking Things Under the Hood.............. 321
Hood Release........................................... 321
Engine Compartment Overview.................. 322
Engine Oil................................................. 323Engine Oil Life System.............................. 326
Engine Air Cleaner/Filter............................ 328
Automatic Transmission Fluid.................... 329
Manual Transmission Fluid........................ 332
Hydraulic Clutch........................................ 334
Engine Coolant.......................................... 335
Radiator Pressure Cap.............................. 338
Engine Overheating................................... 338
Cooling System......................................... 340
Engine Fan Noise..................................... 345
Power Steering Fluid ................................. 345
Windshield Washer Fluid........................... 346
Brakes...................................................... 347
Battery...................................................... 351
Jump Starting............................................ 352
Rear Axle.................................................... 357
Four-Wheel Drive........................................ 358
Front Axle................................................... 358
Section 5 Service and Appearance Care
311

Brake Wear
Your vehicle has four-wheel 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 may come and go or be heard all
the time your vehicle is moving, except when you
are pushing on the brake pedal rmly.
{CAUTION:
The brake wear warning sound means that
soon the brakes will not work well. That
could lead to an accident. When you hear
the brake wear warning sound, have your
vehicle serviced.
Notice:Continuing to drive with worn-out
brake pads could result in costly brake repair.
Some driving conditions or climates may cause
a brake squeal when the brakes are rst applied or
lightly applied. This does not mean something is
wrong with your 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 GM torque
specications.
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
of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc
brakes adjust for wear.
350

Notice:If the other vehicle’s system is not a
12-volt system with a negative ground,
both vehicles can be damaged. Only use
vehicles with 12-volt systems with negative
grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper
cables can reach, but be sure the vehicles are
not touching each other. If they are, it could
cause a ground connection you do not
want. You would not be able to start your
vehicle, and the bad grounding could damage
the electrical systems.
To avoid the possibility of the vehicles rolling,
set the parking brake rmly on both vehicles
involved in the jump start procedure. Put
an automatic transmission in PARK (P) or a
manual transmission in NEUTRAL before
setting the parking brake. If you have a
four-wheel-drive vehicle, be sure the transfer
case is not in NEUTRAL.Notice:If you leave your radio or other
accessories on during the jump starting
procedure, they could be damaged. The repairs
would not be covered by your warranty.
Always turn off your radio and other
accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles.
Unplug unnecessary accessories plugged into
the cigarette lighter or the accessory power
outlets. Turn off the radio and all lamps
that are not needed. This will avoid sparks
and help save both batteries. And it could
save the radio!
353

The proper level is from 0 to 3/8 inch (0 mm to
10 mm) below the bottom of the ller plug
hole, located on the rear axle.
What to Use
SeeRecommended Fluids and Lubricants on
page 440to determine which kind of lubricant
to use.
Four-Wheel Drive
It is recommended that the four-wheel drive
transfer case uid be checked and lled by
your dealer.
Front Axle
It is not necessary to regularly check front axle
uid unless you suspect there is a leak or you hear
an unusual noise. A uid loss could indicate a
problem.
It is recommended that the front axle uid be
checked and lled by your dealer.
Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim has been preset at the factory
and should need no further adjustment.
However, if the vehicle is damaged in an accident,
the headlamp aim may be affected and adjustment
may be necessary.
If oncoming vehicles ash their high beams at
you, this may also mean the vertical aim needs to
be adjusted.
It is recommended that the vehicle is taken to your
dealer for service if the headlamps need to be
re-aimed. It is possible however, to re-aim
the headlamps as described in the following
procedure.
358

How to Check
Use a good quality pocket-type gage to check tire
pressure. You cannot tell if your tires are
properly inated simply by looking at them. Radial
tires may look properly inated even when they
are underinated. Check the tire’s ination
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
Tire Pressure Monitor System
Your vehicle has a Tire Pressure Monitor System
(TPMS). This system uses radio and sensor
technology to check tire pressure levels. TPMS
sensors are mounted onto each tire and wheel
assembly on your vehicle, including the spare tire.
The TPMS sensors monitor the air pressure in
your vehicle’s tires and transmit the tire pressure
readings to a receiver located in the vehicle.
When a low tire pressure condition is detected,
the TPMS will illuminate the low tire pressure
warning light located in the instrument panel
cluster, and at the same time display the LOW
TIRE warning message on the Driver Information
Center (DIC). The low tire pressure warning
light and the LOW TIRE warning message appear
at each ignition cycle until the tires are inated
to the correct ination pressure.
376

TPMS Sensor Identication Codes
Each TPMS sensor has a unique identication
code. Any time you replace one or more of
the TPMS sensors, install the spare tire onto your
vehicle, or rotate your vehicle’s tires, the
identication codes will need to be matched to the
new tire/wheel position. The sensors are
matched to the tire/wheel positions in the following
order: driver’s side front tire, passenger’s side
front tire, passenger’s side rear tire, and driver’s
side rear tire using a TPMS diagnostic tool.
See your dealer for service.
The TPMS sensors may also be matched to each
tire/wheel position by increasing or decreasing
the tire’s air pressure. If increasing the tire’s
air pressure, do not exceed the maximum ination
pressure indicated on the tire’s sidewall.
You will have one minute to match the rst
tire/wheel position, and ve minutes overall, to
match all four tire/wheel positions.If it takes longer than one minute, to match the
rst tire and wheel, or more than ve minutes
to match all four tire and wheel positions
the matching process stops and you will need to
start over.
The TPMS sensor matching procedure is
outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON with the
engine off.
3. Turn the exterior lamp switch from AUTO to
ON four times within three seconds. A double
horn chirp will sound and the TPMS low
tire warning light will begin to ash. The
double horn chirp and ashing TPMS warning
light indicates the TPMS matching process
has started. The TPMS warning light should
continue ashing throughout the matching
procedure. The SERV TPM message will be
displayed on the Driver Information
Center (DIC).
4. Start with the driver’s side front tire.
379

5. Remove the valve cap from the valve cap
stem. Activate the TPMS sensor by
increasing or decreasing the tire’s air pressure
for 10 seconds, then stop and listen for a
single horn chirp. The single horn chirp should
sound within 15 seconds, conrming that
the sensor identication code has been
matched to this tire and wheel position. If you
do not hear the conrming single horn
chirp, you will need to start over with step
number one. To let air-pressure out of a tire
you can use the pointed end of the valve cap,
a pencil-style air pressure gage, or a key.
6. Proceed to the passenger’s side front tire,
and repeat the procedure in Step 5.
7. Proceed to the passenger’s side rear tire,
and repeat the procedure in Step 5.8. Proceed to the driver’s side rear tire, and
repeat the procedure in Step 5.
9. After hearing the conrming horn chirp
for the left rear tire, check to see if
the TPMS warning light is still ashing.
If it is, turn the ignition switch to LOCK.
If the TPMS warning light is not ashing,
the ve minute time limit has passed and
you will need to start the process
over beginning with Step 1.
10. Set all four tires to the recommended air
pressure level as indicated on the Tire
and Loading Information label.
11. Put the valve caps back on the valve stems.
380

Your dealer will know the kind of wheel you need.
Each new wheel should have the same
load-carrying capacity, diameter, width, offset and
be mounted the same way as the one it
replaces.
If you need to replace any of your wheels, wheel
bolts, or wheel nuts, replace them only with
new GM original equipment parts. This way, you
will be sure to have the right wheel, wheel
bolts, and wheel nuts for your vehicle.
{CAUTION:
Using the wrong replacement wheels,
wheel bolts, or wheel nuts on your vehicle
can be dangerous. It could affect the
braking and handling of your vehicle,
make your tires lose air and make you
lose control. You could have a collision
in which you or others could be injured.
Always use the correct wheel, wheel bolts,
and wheel nuts for replacement.Notice:The wrong wheel can also cause
problems with bearing life, brake cooling,
speedometer or odometer calibration,
headlamp aim, bumper height, vehicle ground
clearance, and tire or tire chain clearance
to the body and chassis.
SeeChanging a Flat Tire on page 391for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven.
It could fail suddenly and cause a crash.
If you have to replace a wheel, use a new
GM original equipment wheel.
388