2009 HUMMER H2 brake

Off-Road Recovery
The vehicle’s right wheels can drop off the edge of a
road onto the shoulder while driving.
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off the
accelerator and then, if there is nothing in the way, steer
so that the vehicle straddles the edge of the pavement.
Turn the steering wheel 3 to 5 inches, 8 to 13 cm,
(about one-eighth turn) until the right front tire contacts
the pavement edge. Then turn the steering wheel to go
straight down the roadway.
Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing:
Look down the road, to the sides, and to crossroads
for situations that might affect a successful pass.
If in doubt, wait.
Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double-solid line on your side
of the lane.
Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
Wait your turn to pass a slow vehicle.
When you are being passed, ease to the right.
Loss of Control
Let us review what driving experts say about what
happens when the three control systems — brakes,
steering, and acceleration — do not have enough friction
where the tires meet the road to do what the driver has
asked.
In any emergency, do not give up. Keep trying to steer
and constantly seek an escape route or area of less
danger.
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Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking reasonable
care suited to existing conditions, and by not overdriving
those conditions. But skids are always possible.
The three types of skids correspond to the vehicle’s
three control systems. In the braking skid, the wheels are
not rolling. In the steering or cornering skid, too much
speed or steering in a curve causes tires to slip and lose
cornering force. And in the acceleration skid, too much
throttle causes the driving wheels to spin.
If the vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want
the vehicle to go. If you start steering quickly enough,
the vehicle may straighten out. Always be ready for
a second skid if it occurs.Of course, traction is reduced when water, snow, ice,
gravel, or other material is on the road. For safety, slow
down and adjust your driving to these conditions. It is
important to slow down on slippery surfaces because
stopping distance is longer and vehicle control more
limited.
While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration, or
braking, including reducing vehicle speed by shifting to a
lower gear. Any sudden changes could cause the tires to
slide. You might not realize the surface is slippery until
the vehicle is skidding. Learn to recognize warning
clues —such as enough water, ice, or packed snow on
the road to make a mirrored surface — and slow down
when you have any doubt.
Remember: Any Antilock Brake System (ABS) helps
avoid only the braking skid.
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Brake and Accelerator Operation
Techniques for Off-Road Driving
For logs, walls, rocks, severe ditches,
hills, sand, etc.
1. Bring the vehicle to a complete stop. Do not rev the
engine.
2. Select the proper transmission and transfer case
gear range; usually 1 (First) gear, 4LO LOCK for
such obstacles.
3. If wheel spin is experienced, maintain steady throttle,
with your foot off the brake pedal, to allow the
Traction Control System (TCS) to control the wheel
spin. TCS might not operate if the brakes are
applied.
4. If wheel spin cannot be controlled by the TCS, fully
press the brake pedal with your left foot so all
wheel spin is stopped.
5. Back away from the obstacle so that a new
approach can be tried.
6. As the rst wheel crosses the obstacle, be prepared
to alternate the brake and accelerator pedal to
maintain control and avoid tire drop-off from
obstacles. Repeat this process for the other wheels.
For mounds, washouts, loose up-hill
slopes, ditches, etc.
When wheel spin occurs as the vehicle is moving, the
driver may notice a slight shaking or shuddering of
the vehicle. This should be stopped as soon as possible
to prevent damage to vehicle components. This is the
indication that a loss of traction is occurring on this
terrain. The operator should:
1. Reduce speed and apply the brakes.
2. Assess the terrain properly and adjust vehicle
speed and gear ranges accordingly: 4HI position
for higher speeds and 4LO LOCK for more torque
and lower speeds. Transmission 1 (First) gear
is generally recommended.
3. Apply slight pressure to the brake when the shaking
or shuddering sensation is felt, keeping the vehicle
moving in a controlled manner.
4. Be prepared to alternate between braking and
accelerating through the adverse terrain.
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Surface Obstacles:Unseen or hidden obstacles can
be hazardous. A rock, log, hole, rut, or bump can startle
you if you are not prepared for them. Often these
obstacles are hidden by grass, bushes, snow, or even
the rise and fall of the terrain itself.
Some things to consider:
Is the path ahead clear?
Will the surface texture change abruptly up ahead?
Does the travel take you uphill or downhill?
Will you have to stop suddenly or change direction
quickly?
When driving over obstacles or rough terrain, keep a rm
grip on the steering wheel. Ruts, troughs, or other surface
features can jerk the wheel out of your hands.
When driving over bumps, rocks, or other obstacles, the
wheels can leave the ground. If this happens, even with
one or two wheels, you cannot control the vehicle as well
or at all.
Because you will be on an unpaved surface, it is
especially important to avoid sudden acceleration,
sudden turns, or sudden braking.
Off-roading requires a different kind of alertness from
driving on paved roads and highways. There are no road
signs, posted speed limits, or signal lights. Use good
judgment about what is safe and what is not.
Crossing Obstacles
Approach Angle — a Key to Mobility
If you encounter a large dip in the terrain, do not
enter straight on; enter at an angle — 15° minimum
approach (A), 75° maximum approach angle (B). For
very large dips, ditches or small washes, coast in, using
the engine as a brake (transmission and transfer case
lowest gears). Then, use the low ranges in the
transmission and transfer case to power out.
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Roll The Tires Over Large Rocks
Do not straddle large rocks;
drive over them, letting the
tire cover the rock. The
tread of the tire is thicker
and tougher than the
sidewall of the tire and is
more resilient to impact
than underbody
components.
Log Crossing
Using the proper technique, the vehicle will cross logs
up to 10 inches (25.4 cm) in diameter. Approach the log
at approximately a 15° angle (A) with the transmission
in 1 (First) and the transfer case in 4LO LOCK and “walk”
the vehicle over, one tire at a time. It may be necessary to
modulate the brake pedal and accelerator to avoid
spin-out. Ease the vehicle down from the log with the
brake.
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{CAUTION:
Driving to the top (crest) of a hill at full speed can
cause an accident. There could be a drop-off,
embankment, cliff, or even another vehicle. You
could be seriously injured or killed. As you near
the top of a hill, slow down and stay alert.
If the vehicle stalls, or is about to stall, and you cannot
make it up the hill:
Push the brake pedal to stop the vehicle and keep
it from rolling backwards and apply the parking
brake.
If the engine is still running, shift the transmission to
R (Reverse), release the parking brake, and slowly
back down the hill in R (Reverse).
If the engine has stopped running, you need to
restart it. With the brake pedal pressed, apply
the parking brake. If the vehicle has an automatic
transmission, shift the transmission to P (Park).
Restart the engine. Then, shift to R (Reverse),
release the parking brake, and slowly back down
the hill as straight as possible in R (Reverse).
While backing down the hill, put your left hand on the
steering wheel at the 12 o’clock position so you can
tell if the wheels are straight and can maneuver as
you back down. It is best to back down the hill with
the wheels straight rather than in the left or right
direction. Turning the wheel too far to the left or right
will increase the possibility of a rollover.
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Things not to do if the vehicle stalls, or is about to stall,
when going up a hill:
Never attempt to prevent a stall by shifting into
N (Neutral) to rev-up the engine and regain forward
momentum. This will not work. The vehicle can
roll backward very quickly and could go out
of control.
Never try to turn around if about to stall when going
up a hill. If the hill is steep enough to stall the vehicle,
it is steep enough to cause it to roll over. If you
cannot make it up the hill, back straight down the hill.
If, after stalling, you try to back down the hill and decide
you just cannot do it, set the parking brake, shift to
P (Park), and turn off the engine. Leave the vehicle and
go get some help. Exit on the uphill side and stay clear of
the path the vehicle would take if it rolled downhill. Do not
shift the transfer case to Neutral when you leave the
vehicle. Leave it in some gear.
{CAUTION:
Shifting the transfer case to Neutral can cause
your vehicle to roll even if the transmission is in
P (Park). This is because the Neutral position on
the transfer case overrides the transmission. You
or someone else could be injured. If you are going
to leave your vehicle, set the parking brake and
shift the transmission to P (Park). But do not shift
the transfer case to Neutral. Leave the transfer
case in the 4 HI, 4 HI Lock, or 4 LO Lock position.
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Driving Downhill
When off-roading takes you downhill, consider:
How steep is the downhill? Will I be able to maintain
vehicle control?
What is the surface like? Smooth? Rough?
Slippery? Hard-packed dirt? Gravel?
Are there hidden surface obstacles? Ruts? Logs?
Boulders?
What is at the bottom of the hill? Is there a hidden
creek bank or even a river bottom with large rocks?
If you decide you can go down a hill safely, try to keep
the vehicle headed straight down. Use a low gear
so engine drag can help the brakes so they do not have
to do all the work. Descend slowly, keeping the
vehicle under control at all times.
{CAUTION:
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could cause
loss of control and a serious accident. Apply the
brakes lightly when descending a hill and use a low
gear to keep vehicle speed under control.Things not to do when driving down a hill:
When driving downhill, avoid turns that take you
across the incline of the hill. A hill that is not too
steep to drive down might be too steep to drive
across. The vehicle could roll over.
Never go downhill with the transmission in
N (Neutral), called free-wheeling. The brakes will
have to do all the work and could overheat
and fade.
Vehicles are much more likely to stall when going uphill,
but if it happens when going downhill:
1. Stop the vehicle by applying the regular brakes and
apply the parking brake.
2. Shift to P (Park). While still braking, restart the
engine.
3. Shift back to a low gear, release the parking brake,
and drive straight down.
4. If the engine will not start, get out and get help.
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