cooling HUMMER H2 2004 User Guide

A. Coolant Surge Tank. SeeCooling System on
page 5-30andCoolant Surge Tank Pressure Cap
on page 5-27.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-19.
C. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-37.
D. Engine Oil Fill. SeeEngine Oil on page 5-14.
E. Engine Oil Dipstick. SeeEngine Oil on page 5-14.
F. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-21.
G. Fan. SeeCooling System on page 5-30andEngine
Fan Noise on page 5-35.H. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-43.
I. Power Steering Fluid Reservoir (Out of View). See
Power Steering Fluid on page 5-36.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-43.
K. Brake Fluid Reservoir. SeeBrakes on page 5-38.
L. Underhood Fuse Block. See “Underhood Fuse Block”
underFuses and Circuit Breakers on page 5-102.
M. Battery. SeeBattery on page 5-42.
Before closing the hood, be sure all ller caps are on
properly. Pull down the hood and close it rmly.
5-13

Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs rst, if you add
only DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t need to add anything else.
5-24

{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
5-25

If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
2. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving – DRIVE (D).
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,turn off the
engine and get everyone out of the vehicleuntil it
cools down. Also, see “Overheated Engine Protection
Operating Mode” listed previously in this section.
You may decide not to lift the hood but to get service
help right away.Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Fan
If the coolant inside the coolant surge tank is boiling,
don’t do anything else until it cools down. The vehicle
should be parked on a level surface.
5-30

The coolant level should
be at or above the FULL
COLD mark. If it isn’t,
you may have a leak at the
pressure cap or in the
radiator hoses, heater
hoses, radiator, water
pump or somewhere else
in the cooling system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them. If
you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it doesn’t, your vehicle needs service. Turn off
the engine.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
“Overheated Engine Protection Operating Mode”
in the Index for information on driving to a safe
place in an emergency.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-31

How to Add Coolant to the Coolant
Surge Tank
If you haven’t found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level isn’t at or above the FULL
COLD mark, add a 50/50 mixture ofclean, drinkable
waterand DEX-COOL
®coolant at the coolant
surge tank, but be sure the cooling system, including
the coolant surge tank pressure cap, is cool before you
do it. SeeEngine Coolant on page 5-24for more
information.
If no coolant is visible in the surge tank, add coolant as
follows:
{CAUTION:
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 radiator
pressure cap — even a little — they can
CAUTION: (Continued)
CAUTION: (Continued)
comeout at high speed. Never turn the cap
when the cooling system, including the
radiator pressure cap, is hot. Wait for the
cooling system and radiator pressure cap to
cool if you ever have to turn the pressure cap.
5-32

{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will.
Yourvehicle’s coolant warning system is set
for the proper coolant mixture. With plain
water or the wrong mixture, your engine could
get too hot but you would not get the overheat
warning. Your engine could catch re and you
or others could be burned. Use a 50/50 mixture
of clean, drinkable water and DEX-COOL
®
coolant.
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{CAUTION:
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.
1. Park the vehicle on a level surface.
2. Locate the coolant
surge tank pressure
cap that has this label.
You can remove the coolant surge tank pressure
capwhen the cooling system, including the
coolant surge tank pressure cap and upper radiator
hose, are no longer hot. Turn the pressure cap
slowly counterclockwise (left) about one full turn. If
you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
5-33

5. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan.
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 FULL COLD mark.
6. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your 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 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 partially
disengages.
5-35

Wheel Replacement
Replace any wheel that is bent, cracked or badly rusted
or corroded. If wheel nuts keep coming loose, the
wheel, wheel bolts and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer if any of these conditions exist.
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 5-79for more
information.
5-74

Capacities and Specications
Please refer toRecommended Fluids and Lubricants on page 6-12for more information. All capacities are
approximate.
Engine Specications
Engine VIN Code Spark Plug Gap
VORTEC™ 6000 V8 U 0.040 inches (1.01 mm)
Capacities and Specications
ApplicationCapacities
English Metric
Cooling System 13.0 quarts 12.7 L
After rell, the level must be rechecked. SeeCooling System on page 5-30.
Engine Oil with Filter 6.0 quarts 5.7 L
After rell, the level must be rechecked. Add enough engine oil so that the uid is within the proper operating
range. SeeEngine Oil on page 5-14.
Fuel Tank 32.0 gallons 121.0 L
Air Conditioning Refrigerant R-134a 1.6 lbs. 0.7 kg
Wheels and Tires
Application Description Torque
Wheel Nuts 8 bolts (14 mm) 140 lb ft (190Y)
Tire Pressure See the Certication/Tire label on the rear edge of the driver’s door.
5-111