brake HUMMER H3 2010 Workshop Manual

Driving and Operating 9-73
Vehicles with an automatic
transmission can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts too
often under heavy loads and/or
hilly conditions. For vehicles with a
manual transmission, it is better not
to use the highest gear.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)
for a few minutes before turning the
engine off. For vehicles with manualtransmissions, let the engine run
while parked, preferably on level
ground, with the transmission out of
gear and the parking brake applied,
for a few minutes before turning the
engine off. If the overheat warning
comes on, see
Engine Overheating
on page 10‑22.
Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet for
vehicles with an automatic
transmission, or into gear
for vehicles with a manual
transmission. Turn the 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 brake pedal
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park) for vehicles with an
automatic transmission or into
gear for vehicles with a manual
transmission.
5. Release the brake pedal.

9-74 Driving and Operating
Leaving After Parking on a Hill
1. Apply and hold the brake pedalwhile you:
.start the 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.
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See this
manual's Maintenance Schedule
or Index for more information.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle lubricant, belts, cooling system and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See
Engine Overheating
on page 10‑22.
Trailer Towing
Three important considerations
have to do with weight:
.The weight of the trailer.
.The weight of the trailer tongue.
.The total weight on the vehicle's
tires.
Weight of the Trailer
How heavy can a trailer safely be?
Speed, altitude, road grades,
outside temperature, special
equipment, and the amount of
tongue weight the vehicle can carry
must be considered. See “Weight of
the Trailer Tongue” later in this
section for more information.
Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment.
The weight of additional optional
equipment, passengers and cargo in
the tow vehicle must be subtracted
from the maximum trailer weight.
Use the following chart to determine
how much a vehicle can weigh,
based on the vehicle model and
options.

Driving and Operating 9-79
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue
of the trailer to help prevent the
tongue from contacting the road if it
becomes separated from the hitch.
Always leave just enough slack so
the rig can turn. Never allow safety
chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 680 kg (1,500 lbs) needs to
have its own brake system that
is adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted and
maintained properly.
Trailer Wiring Harness
Light‐Duty Trailer Wiring Package
If the vehicle does not have a
trailer towing package, the chassis
harness will contain the following
blunt cut circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.White: Ground
.Brown: Tail Lamps
To add a trailer towing wiring
package, have it installed by
your dealer or a qualified service
center. Also, see Add-On Electrical
Equipment
on page 9‑81for more
information. Heavy-Duty Trailer Wiring Package
If the vehicle has a trailer towing
package, the rear bumper harness
will have a seven‐pin universal
heavy‐duty trailer connector
attached to a bracket on the hitch
platform.

9-80 Driving and Operating
The trailer towing harness contains
the following seven trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed
.Dark Blue: Trailer Brake
If charging a remote (non‐vehicle)
battery, turn on the headlamps to
boost the vehicle system voltage to
properly charge the battery. Four-Wire Harness Adapter
If towing a light-duty trailer with
a standard four-way, flat pin
connector, an adapter is available
from your dealer.
Hold the adapter with the tab
pointing up.
Connect the adapter to the
seven‐pin universal heavy‐duty
trailer connector attached to the
bracket on the hitch platform. The
flip cap on the vehicle's harness
locks onto the tab and helps hold
the adapter in place. Plug the
four-way pin connector onto the
adapter.

Driving and Operating 9-81
Trailer Brake Control Wiring
Harness
The trailer brake control wiring
harness is located under the
instrument panel to the right of the
steering column. The wires are
taped to the harness that goes
to the courtesy light under the
instrument panel. The harness
has the following wires:
.Red Wire: AUX B+
.Black Wire: Ground
.Light Blue Wire: Brake Signal
.Dark Blue Wire: Trailer Brakes
Trailer Recommendations
Subtract the hitch loads from the
Cargo Weight Rating (CWR). CWR
is the maximum weight of the load
the vehicle can carry. It does not
include the weight of the people
inside, but you can figure about
68 kg (150 lbs) for each passenger.
The total cargo load must not be
more than the vehicles CWR.
Weigh the vehicle with the trailer
attached, so the GVWR or GAWR
are not exceeded. If using a
weight-distributing hitch, weigh the
vehicle without the spring bars in
place.
The best performance is obtained
by correctly spreading out the
weight of the load and choosing the
correct hitch and trailer brakes.
For more information seeTrailer
Towing on page 9‑74.
Conversions and
Add-Ons
Add-On Electrical
Equipment
Notice: Do not add anything
electrical to the vehicle unless
you check with your dealer first.
Some electrical equipment can
damage the vehicle and the
damage would not be covered
by the vehicle's warranty. Some
add-on electrical equipment can
keep other components from
working as they should.
Add-on equipment can drain the
vehicle battery, even if the vehicle is
not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle
on page 3‑40and Adding
Equipment to the Airbag-Equipped
Vehicle on page 3‑40.

Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-9
Engine Oil Life System . . . . . 10-11
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-12
Manual Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-15 Hydraulic Clutch . . . . . . . . . . . . 10-16
Engine Air Cleaner/Filter . . . . 10-17
Cooling System . . . . . . . . . . . . 10-18
Engine Coolant . . . . . . . . . . . . . 10-19
Engine Overheating . . . . . . . . 10-22
Engine Fan . . . . . . . . . . . . . . . . . 10-24
Power Steering Fluid . . . . . . . 10-24
Washer Fluid . . . . . . . . . . . . . . . 10-25
Brakes . . . . . . . . . . . . . . . . . . . . . 10-26
Brake Fluid . . . . . . . . . . . . . . . . . 10-27
Battery . . . . . . . . . . . . . . . . . . . . . 10-28
Four-Wheel Drive . . . . . . . . . . . 10-29
Front Axle . . . . . . . . . . . . . . . . . . 10-29
Rear Axle . . . . . . . . . . . . . . . . . . 10-29
Starter Switch Check . . . . . . . 10-30
Automatic Transmission Shift
Lock Control System
Check . . . . . . . . . . . . . . . . . . . . . 10-30
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-31
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-31
Wiper Blade Replacement . . . . . . . . . . . . . . 10-32
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-33
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-35
Halogen Bulbs . . . . . . . . . . . . . . 10-35
Headlamps . . . . . . . . . . . . . . . . . 10-35
Taillamps, Turn Signal,Stoplamps, and Back-Up
Lamps (H3) . . . . . . . . . . . . . . . 10-35
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps (H3T) . . . . . . . . . . . . . . 10-36
License Plate Lamp . . . . . . . . 10-37
Replacement Bulbs . . . . . . . . . 10-37
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-38
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-39
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-39

Vehicle Care 10-3
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
remote keyless transmitters, may
contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non‐dealer/non‐retailer
accessories to the vehicle can affect
vehicle performance and safety,
including such things as airbags,
braking, stability, ride and handling,
emissions systems, aerodynamics,
durability, and electronic systems
like antilock brakes, traction control,
and stability control. Some of these
accessories could even cause
malfunction or damage not covered
by the vehicle warranty.
Damage to vehicle components
resulting from the installation or
use of non‐certified parts, including
control module modifications, isnot covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
HUMMER Accessories are
designed to complement and
function with other systems on
the vehicle. Your HUMMER
dealer/retailer can accessorize the
vehicle using genuine HUMMER
Accessories. When you go to your
HUMMER dealer/retailer and ask
for HUMMER Accessories, you will
know that HUMMER-trained and
supported service technicians will
perform the work using genuine
HUMMER Accessories.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle
on
page 3‑40.

Vehicle Care 10-7
A. Windshield Washer FluidReservoir. See “Adding Washer
Fluid” under Washer Fluid
on
page 10‑25.
B. Engine Coolant Recovery Tank. See Engine Coolant
on
page 10‑19.
C. Engine Air Cleaner/Filter
on
page 10‑17.
D. Power Steering Fluid Reservoir. See Power Steering Fluid
on
page 10‑24.
E. Automatic Transmission Fluid Dipstick (If Equipped). See
“Checking the Fluid Level” under
Automatic Transmission Fluid
on
page 10‑12.
F. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10‑9. G. Radiator Pressure Cap. See
Cooling System on page 10‑18.
H. Remote Negative (−) Terminal (GND). See Jump Starting
on
page 10‑86.
I. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10‑9.
J. Positive (+) Battery Terminal. See Jump Starting
on
page 10‑86.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 10‑26.
L. Engine Compartment Fuse
Block on page 10‑39.
M. Battery on page 10‑28.
N. Hydraulic Clutch Fluid Reservoir (If Equipped). See Hydraulic
Clutch on page 10‑16.

Vehicle Care 10-9
A.Engine Air Cleaner/Filteron
page 10‑17.
B. Air Filter Restriction Indicator (If Equipped). See Engine Air
Cleaner/Filter
on page 10‑17.
C. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
on
page 10‑25.
D. Engine Coolant Recovery Tank. See Engine Coolant
on
page 10‑19.
E. Automatic Transmission Fluid Dipstick (If Equipped). See
“Checking the Fluid Level” under
Automatic Transmission Fluid
on
page 10‑12. F. Engine Oil Dipstick. See
“Checking Engine Oil” under
Engine Oil on page 10‑9.
G. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10‑9.
H. Brake Fluid Reservoir. See “Brake Fluid” underBrakes
on
page 10‑26.
I. Battery on page 10‑28.
J. Power Steering Fluid Reservoir. See Power Steering Fluid
on
page 10‑24.
K. Engine Compartment Fuse
Block on page 10‑39.
L. Radiator Pressure Cap. See Cooling System on page 10‑18.
Engine Oil
Checking Engine Oil
It is a good idea to check the engine
oil level at each fuel fill. In order to
get an accurate reading, the oil
must be warm and the vehicle must
be on level ground.
The engine oil dipstick handle
is a yellow loop. See Engine
Compartment Overview
on
page 10‑6for the location of the
engine oil dipstick.
1. Turn off the engine and give the oil several minutes to drain back
into the oil pan. If this is not
done, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper towel or cloth,
then push it back in all the way.
Remove it again, keeping the tip
down, and check the level.

Vehicle Care 10-13
Notice:Too much or too
little fluid can damage the
transmission. Too much can
mean that some of the fluid could
come out and fall on hot engine
parts or exhaust system parts,
starting a fire. Too little fluid
could cause the transmission to
overheat. Be sure to get an
accurate reading if checking the
transmission fluid.
Wait at least 30 minutes before
checking the transmission fluid level
if you have been driving:
.When outside temperatures are
above 32°C (90°F).
.At high speed for quite a while.
.In heavy traffic —especially in
hot weather.
.While pulling a trailer.
To get the right reading, the fluid
should be at normal operating
temperature, which is 82°C to 93°C
(180°F to 200°F). Get the vehicle warmed up by
driving about 24 km (15 miles) when
outside temperatures are above
10°C (50°F). If it is colder than 10°C
(50°F), drive the vehicle in 3 (Third)
until the engine temperature gauge
moves and then remains steady for
10 minutes.
A cold fluid check can be made
after the vehicle has been sitting
for eight hours or more with the
engine off, but this is used only
as a reference. Let the engine run
at idle for five minutes if outside
temperatures are 10°C (50°F) or
more. If it is colder than 10°C
(50°F), the engine might have to
idle longer. Should the fluid level be
low during this cold check, check
the fluid hot before adding fluid.
Checking the fluid hot gives a more
accurate reading of the fluid level.
Checking the Fluid Level
To prepare the vehicle:
1. Park the vehicle on a level
place. Keep the engine running.
2. With the parking brake applied, place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever
through each gear range,
pausing for about three seconds
in each range. Then, position the
shift lever in P (Park).
4. Let the engine run at idle for three minutes or more.