2003 CHEVROLET EXPRESS CARGO VAN service

When to Change Engine Oil
If any one of these are true for you, use the short
trip/city maintenance schedule:
·Most trips are less than 5 miles (8 km). This is
particularly important when outside temperatures
are below freezing.
·Most trips include extensive idling (such as frequent
driving in stop-and-go traffic).
·You frequently tow a trailer or use a carrier on top
of your vehicle.
·The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and ®lter
every 3,000 miles (5 000 km) or 3 months Ð whichever
occurs ®rst.
If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and ®lter every
7,500 miles (12 500 km) or 12 months Ð whichever
occurs ®rst. Driving a vehicle with a fully warmed engine
under highway conditions will cause engine oil to
break down slower.
How to Reset the CHANGE ENGINE
OIL Light
The GM Oil Life System calculates when to change
your engine oil and ®lter based on vehicle use. Anytime
your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change your oil prior to a
CHANGE ENGINE OIL light being turned on, reset the
system.
To reset the CHANGE ENGINE OIL light, do the
following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal
three times within ®ve seconds.
3. If the CHANGE ENGINE OIL light ¯ashes for ®ve
seconds, the system is reset.
If the system does not reset, try the procedure once
again. If it still does not reset, see your dealer for
service.
See
Change Engine Oil Light on page 3-37.
5-16

What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Don't let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer's
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
®lter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling center
for help.
Engine Air Cleaner/Filter
SeeEngine Compartment
Overview on page 5-12
for the location of the
engine air cleaner/®lter
and change indicator
(if equipped).
When to Inspect the Engine Air
Cleaner/Filter
If your vehicle is equipped with a ®lter change indicator
it will let you know when the ®lter needs to be
replaced. When the change indicator turns black or is in
the red/orange change zone, change the ®lter and
reset the indicator. Vehicles without a change indicator
inspect the air cleaner/®lter every 15,000 miles
(25 000 km) and replace the ®lter every 30,000 miles
(50 000 km). If you are driving in dusty/dirty conditions,
inspect the ®lter or change indicator at each engine
oil change.
5-17

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission ¯uid
level is when the engine oil is changed.
Change both the ¯uid and ®lter every 50,000 miles
(83,000 km) if the vehicle's GVWR is over 8,600 or if
the vehicle is mainly driven under one or more of these
conditions:
·In heavy city traffic where the outside temperature
regularly reaches 90ÉF (32ÉC) or higher.
·In hilly or mountainous terrain.
·When doing frequent trailer towing.
·Uses such as found in taxi, police or delivery
service.
If your vehicle's GVWR is not over 8,600 and you do
not use your vehicle under any of these conditions,
change the ¯uid and ®lter every 100,000 miles
(166 000 km).
See
Part A: Scheduled Maintenance Services on
page 6-4.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little ¯uid can damage
your transmission. Too much can mean that some
of the ¯uid could come out and fall on hot engine
part or exhaust system parts, starting a ®re.
Too little ¯uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission ¯uid.
Wait at least 30 minutes before checking the
transmission ¯uid level if you have been driving:
·When outside temperatures are above 90ÉF (32ÉC).
·At high speed for quite a while.
·In heavy traffic ± especially in hot weather.
·While pulling a trailer.
To get the right reading, the ¯uid should be at
normal operating temperature, which is 180ÉF to 200ÉF
(82ÉC to 93ÉC).
5-19

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, and you have not stopped, 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.
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. Radiator Pressure Cap
B. Coolant Recovery Tank
C. Engine Cooling Fan(s)
If the coolant inside the coolant recovery tank is boiling,
don't do anything else until it cools down.
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When the engine is cold,
the coolant level should be
at or above the COLD
FILL 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. Don't touch them. If you
do, you can be burned.
Don't 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.
See if the engine cooling fan speed increases 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 isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index for information on driving to a
safe place in an emergency.
Notice:When adding coolant, it is important that
you use only DEX-COOLž(silicate-free) coolant.
If coolant other than DEX-COOLžis added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner Ð at 30,000 miles
(50 000 km) or 24 months, whichever occurs ®rst.
Damage caused by the use of coolant other
than DEX-COOL
žis not covered by your new vehicle
warranty.
If there seems to be no leak, start the engine again.
See if the engine cooling fan speed increases when idle
speed is doubled by pushing the accelerator pedal
down. If it doesn't, your vehicle needs service. Turn off
the engine.
5-27

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 your brakes won't 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 speci®cations.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6-17.
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.
5-39

7. Don't let the other end
touch metal. Connect it
to the positive (+)
terminal of the good
battery. Use a remote
positive (+) terminal
if the vehicle has one.
8. Now connect the black
negative (-) cable to
the negative (-)
terminal of the good
battery. Use a remote
negative (-) terminal
if the vehicle has one.Don't let the other end touch anything until the next
step. The other end of the negative (-) cable
doesn't go to the dead battery. It goes to a heavy,
unpainted metal engine part or to a remote
negative (-) terminal on the vehicle with the dead
battery.
9. Connect the other end of the negative (-) cable
to the negative (-) terminal of the dead battery or
to a remote negative (-) terminal if the vehicle
has one.
10. Now start the vehicle with the good battery and run
the engine for a while.
11. Try to start the vehicle with the dead battery. If it
won't start after a few tries, it probably needs
service.
Notice:Damage to your vehicle may result from
electrical shorting if jumper cables are removed
incorrectly. To prevent electrical shorting, take care
that the cables don't touch each other or any
other metal. The repairs wouldn't be covered by
your warranty.
5-44

Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeePart A: Scheduled
Maintenance Services on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If you have the 1500 Series, the proper level is from
5/8 inch (15 mm) to 1 5/8 inch (40 mm) below the
bottom of the ®ller plug hole. The proper level for the
2500 and 3500 Series is from 0 to 1/4 (6 mm) below the
bottom of the ®ller plug hole. Add only enough ¯uid to
reach the proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeePart D: Recommended
Fluids and Lubricants on page 6-18.
5-47