light CHEVROLET C/K 2003 Owner's Manual

2-34 Rear Air Suspension Dump Control
If your vehicle is equipped with the Hendrickson HAS
Series single
-axle air suspension, you have this control.
The air suspension dump control allows the operator to
lower the deck height approximately 4.5 inches
(11.5 cm) from the normal frame height.
The switch to deflate and
inflate the air suspension is
located in the instrument
panel switchbank.
Press the bottom of the switch to deflate the air
suspension and lower the deck height. Press the top
of the switch to return the suspension to normal
deck height.
An indicator light will come on and stay on whenever
the switch is in the dumped position.
Automatic Transmission Operation
We build vehicles with five and six-speed automatic
transmissions. This part of the manual covers the basics
of these. With some of the transmissions, you will find
another manual in your vehicle that goes into more
detail. On the headliner, in front of and above the driver,
or in some other place near the driver, you will see a
label that describes important operating facts about the
automatic transmission in your vehicle. Make sure you
follow the instructions on this label.
Be sure to keep your parking brake set until you are
ready to shift into DRIVE (D), and press the brake pedal
while shifting from NEUTRAL (N) or PARK (P) to a
drive gear.
All vehicles equipped with automatic transmissions
can be started in PARK (P), if equipped, or in
NEUTRAL (N). See the Allison

Transmission
Operator's Manual in your vehicle for more information
about this.

2-36 Overdrive Defeat (If Equipped)
If your vehicle has this feature, you can select not to
shift up to fifth gear. This is useful when towing or
under a heavy load.
The overdrive defeat switch
is located in the instrument
panel to the right of the
steering column.
Press the switch to limit the transmission to fourth gear.
This will allow for better fuel economy and fewer
downshifts while pulling a tractor or trailer or under a
heavy load. The indicator light in the switch will come
on whenever overdrive defeat is active.
Manual Transmission Operation
Using the Clutch
When you're starting to move the vehicle, it's important
to begin with the engine speed at idle. Then start to
engage the clutch and listen for an engine speed drop
of about 100 rpm. At this point, the clutch is engaging,
so you should increase the engine speed and fully
engage the clutch. It's important not to increase the
engine speed sooner or before the clutch begins it's
engagement. If you do, you can cause damage to
your vehicle.
Double-Clutching
You must use the double-clutching method when you
shift an unsynchronized gear set. Disengage the clutch,
shift to neutral and engage the clutch. When upshifting,
slow the engine until the engine rpm and road speed
match. When downshifting, accelerate the engine until
the engine rpm and road speed match. Then quickly
disengage the clutch and move the shift lever to the next
gear position and engage the clutch.

2-38
During the first 500 miles (805 km) of vehicle use, start
the vehicle moving in FIRST (1) gear. This allows the
clutch components to wear
-in properly.
FIRST (1): With the vehicle at a stop, release the brake,
press the clutch pedal and shift into FIRST (1). Then,
slowly let up on the clutch pedal as you press the
accelerator pedal. Only downshift into FIRST (1) when
the vehicle has come to a complete stop. If the shift
lever will not go into FIRST (1), put the lever in neutral
and let up on the clutch pedal to fully engage the clutch.
Press the clutch pedal again. Then, shift into FIRST (1).
SECOND (2): With the vehicle at a stop, release the
brake, press the clutch pedal and shift into
SECOND (2). Then, slowly let up on the clutch pedal as
you press the accelerator pedal. With the vehicle
moving, press the clutch pedal and upshift into
SECOND (2) from FIRST (1) while applying light
pressure to the right on the shifter. Then, slowly let up
on the clutch pedal as you press the accelerator pedal.
If you come to a complete stop and the shift lever will
not go into SECOND (2), put the lever in neutral and let
up on the clutch pedal to fully engage the clutch. Press
the clutch pedal again. Then, shift into SECOND (2).THIRD (3): Press the clutch pedal and upshift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
FOURTH (4), FIFTH (5) and SIXTH (6): Upshift
into the higher forward gears the same way as you do
THIRD (3). Slowly let up on the clutch pedal as you
press the accelerator pedal.
NEUTRAL: Use this position when you start or idle
your engine.
REVERSE (R): To back up, press the clutch pedal.
Wait for the vehicle to stop moving and then, shift to
REVERSE (R). Let up on the clutch slowly while
pressing the accelerator pedal. Also, use REVERSE (R),
along with the parking brake, when turning off your
engine and parking your vehicle.

2-39 Eaton Fuller Nine and Ten-Speed
Non-Synchronized Manual Transmissions
(If Equipped)
If your vehicle has one of these unsynchronized
transmissions, it's naturally somewhat complicated.
The label above the windshield will tell you the
operating basics you need to know.
The following are driving tips.

Always choose an initial starting gear suitable for
the load and terrain.

Always use double
-clutching procedures
when shifting.

Never move the range shift lever to the LO speed
gear position after HI range preselection, or anytime
the transmission is in the HI range.

Never move the range knob or lever with the shift
lever in NEUTRAL while the vehicle is moving.

Never make a range shift while moving
in REVERSE (R).
Clutch Brake (Vehicles with
Non-Synchronized Transmission)
A clutch brake is used to stop transmission input shaft
rotation so that FIRST (1) or REVERSE (R) gear
selection can be initiated when the vehicle is at a
standstill and the engine is idling.
Press the clutch pedal all the way down to the
floorboard to apply the clutch brake.
When using the clutch brake, disengage the clutch pedal
and shift the transmission into either the initial starting
gear or REVERSE (R). If the tooth
-butting occurs
between the clutching teeth, re
-engage the clutch while
applying light pressure to the shift lever. This will
provide for a smooth shift into either FIRST (1) or
REVERSE (R) gear.
NOTICE:
After engaging FIRST (1) or REVERSE (R) gear,
do not use the clutch brake for upshifting and
downshifting. To do so will shorten the service life
of the clutch brake and gear selection shift efforts
may be increased.

2-41
To set the hand lever parking brake, pull up on the
handle with your right hand, until it stops.
If the ignition is on when the parking brake is set, the
brake system warning light will come on.
To release the foot pedal parking brake, hold the regular
brake pedal down. Pull the brake release handle, located
just above the parking brake pedal, to release the
parking brake.
To release the hand lever parking brake, push down on
the handle until it stops.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
NOTICE:
Driving with the parking brake on can cause
your rear brakes to overheat. You may have to
replace them, and you could also damage other
parts of your vehicle. Always check to be sure
your parking brake is fully released before
you drive.
Propshaft Park Brake Burnish Procedure
It is recommended that the propshaft-mounted parking
brake be burnished as part of the new vehicle break
-in.
The parking brake will work best after it has been
burnished following these instructions:
Make 10 stops, using the parking brake hand lever or
foot pedal, from 20 mph (32 km/h) about 2 1/2 miles
(4 km) apart. Between stops, drive the vehicle at
20 mph (32 km/h).

2-42 Air Brake (If Equipped)
CAUTION:
When the yellow SYSTEM PARK and the red
TRAILER AIR SUPPLY knobs are both pushed
in, your rig will be free to move. It could strike
someone or something. When both of these knobs
are pushed in, hold the regular brake pedal down
to keep your rig from moving.
If your vehicle has air
brakes, you will have this
parking brake. It is located
above the radio in the
instrument panel.
Pulling it out applies the parking brake. The park brake
light will come on when the air parking brake is applied.

2-44
CAUTION:
If you apply any one of the air brake parking
controls while the vehicle is moving, your rig will
stop suddenly. If you are not ready for this, you
or others could be injured. Don't apply any one
of these controls while you're driving, unless you
have to make an emergency stop.
If the air pressure drops below 60 to 70 psi (413 to
482 kPa), the primary brake light and warning buzzer
will come on. If the air pressure drops to 35 to 45 psi
(241 to 310 kPa), the red trailer air supply knob will
automatically pop out and apply the spring brakes on
the trailer.If the air pressure drops to 35 to 45 psi (241 to 310 kPa),
the yellow park brake knob will automatically pop out
and apply the spring brakes on the truck or tractor.
If you ever have a complete loss of air so that your air
brakes automatically apply, there is a way that the tow
operator can release the parking brakes to tow the
vehicle. See ªTowing Your Vehicleº in the Index.
CAUTION:
If your vehicle is left in gear, the engine can start
if the vehicle starts to roll. This can easily happen
if you have the diesel engine. Shift the
transmission into NEUTRAL (N) before you
leave the vehicle.

2-49 Turn and Lane-Change Signals
The turn signal has two upward (for right) and two
downward (for left) positions. These positions allow you
to signal a turn or a lane change.
To signal a turn, move the lever all the way up or down.
When the turn is finished, the lever will return
automatically.
An arrow on the instrument
panel cluster will flash in
the direction of the turn or
lane change.
To signal a lane change, just raise or lower the lever
until the arrow starts to flash. Hold it there until you
complete your lane change. The lever will return by
itself when you release it.As you signal a turn or a lane change, if the arrows don't
flash but just stay on, check the turn signal flasher and
circuit breaker. See ªFuses and Circuit Breakersº in
the Index.
If a bulb is burned out, replace it to help avoid an
accident. If the arrows don't go on at all when you
signal a turn, check the circuit breaker and for
burned
-out bulbs. (See ªFuses and Circuit Breakersº
in the Index.)
Headlamp High/Low-Beam Changer
To change the headlamps from low to high beam or high
to low beam, pull the multifunction lever all the way
toward you, then release it.
When the high beams are
on, this light on the
instrument panel cluster
will also be on.

2-50 Windshield Wipers
You control the windshield
wipers by turning the band
with the wiper symbol on it.
(Off): Turn the band on the lever to this symbol to
turn off the windshield wipers.
(Mist): For a single wiping cycle, turn the band to
this symbol. Hold it there until the wipers start, then let
go. The wipers will stop after one cycle. If you want
more cycles, hold the band on mist longer.
You can set the wiper speed for a long or short delay
between wipes. This can be very useful in light rain or
snow. Turn the band to one of the four delay settings to
choose the delay time. The further the band is turned
upward, the longer the delay will be. The further the
band is turned downward, the shorter the delay will be.
(Low Speed): For steady wiping at low speed,
turn the band toward you to the first solid band below
the delay settings.
(High Speed): For high-speed wiping, turn the
band further, to the second solid band below the delay
settings. To stop the wipers, move the band to off.
Be sure to clear ice and snow from the wiper blades
before using them. If they are frozen to the windshield,
carefully loosen or thaw them. If your blades do become
worn or damaged, get new blades or blade inserts. For
more information, see ªWindshield Wiper Blade
Replacementº in the Index.
Heavy snow or ice can overload your wipers. The
windshield wiper motor is protected from overload by a
circuit breaker and a fuse. If the motor overheats due to
heavy snow or ice the wiper will stop until the motor
cools. Although the circuit is protected from electrical
overload, overload due to heavy snow or ice may cause
wiper linkage damage. Always clear ice and heavy snow
from the windshield before using your windshield wipers.

2-54
Reducing Speed While Using Cruise Control
Press in the button at the end of the lever until you reach
the lower speed you want, then release it.
To slow down in very small amounts, tap the
button briefly. Each time you do this, you'll go
1 mph (1.6 km/h) slower.
Passing Another Vehicle While Using Cruise Control
Use the accelerator pedal to increase your speed. When
you take your foot off the pedal, your vehicle will slow
down to the cruise control speed you set earlier.
Using Cruise Control on Hills
How well your cruise control will work on hills depends
upon your speed, load and the steepness of the hills.
When going up steep hills, you may want to step on the
accelerator pedal to maintain your speed. When going
downhill, you may have to brake or shift to a lower gear
to keep your speed down. Of course, applying the brake
or clutch takes you out of cruise control. Many drivers
find this to be too much trouble and don't use cruise
control on steep hills.Ending Cruise Control
There are four different ways to turn off the cruise
control:

Step lightly on the brake pedal (manual and
automatic transmissions).

Press the clutch pedal to the floor (manual
transmissions).

Move the cruise switch to off, or

Shift the transmission to NEUTRAL (N).
Erasing Speed Memory
When you turn off the ignition, your cruise control set
speed memory is erased.