2004 CHEVROLET ASTRO CARGO VAN fuel cap

3
6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.
Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of
the ller neck, reinstall the pressure cap. Be sure
the arrow on the pressure cap lines up.
Engine Fan Noise
This 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 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 when the clutch
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 disengages.
5-37

Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to
its width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.
Cold Ination Pressure:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
or kilopascals (kPa) before a tire has built up heat from
driving. SeeInation - Tire Pressure on page 5-70.Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the
U.S. Department of Transportation motor vehicle safety
standards. The DOT code includes the Tire Identication
Number (TIN), an alphanumeric designator which can
also identify the tire manufacturer, production plant,
brand and date of production.
GVWR:Gross Vehicle Weight Rating, seeLoading
Your Vehicle on page 4-29.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-29.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-29.
Intended Outboard Sidewall:The side of an
asymmetrical tire, that must always face outward when
mounted on a vehicle.
Kilopascal (kPa):The metric unit for air pressure.
There are 6.9 kPa’s to one psi.
Light Truck (LT-Metric) Tire:A tire used on light duty
trucks and some multipurpose passenger vehicles.
5-68

UTQGS:Uniform Tire Quality Grading Standards,
a tire information system that provides consumers with
ratings for a tire’s traction, temperature and treadwear.
Ratings are determined by tire manufacturers using
government testing procedures. The ratings are molded
into the sidewall of the tire. SeeUniform Tire Quality
Grading on page 5-74.
Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs. (68 kg) plus
the rated cargo load. SeeLoading Your Vehicle
on page 4-29.
Vehicle Maximum Load on the Tire:Load on an
individual tire due to curb weight, accessory weight,
occupant weight and cargo weight.
Vehicle Placard:A label permanently attached to
a vehicle showing the original equipment tire size and
recommended ination pressure. SeeLoading Your
Vehicle on page 4-29.
Ination - Tire Pressure
The Certication/Tire label or Tire and Loading
Information label shows the correct ination pressures
for your tires when they’re cold. “Cold” means your
vehicle has been sitting for at least three hours or driven
no more than 1 mile (1.6 km). SeeLoading Your
Vehicle on page 4-29.Notice:Don’t let anyone tell you that underination
or overination is all right. It’s not. If your tires
don’t have enough air (underination), you can get
the following:
Too much exing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overination),
you can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the compact spare tire.
It should be at 60 psi (420 kPa).
5-70

Capacities and Specications
The following approximate capacities are given in English and metric conversions. Please refer to
Part D: Recommended Fluids and Lubricants on page 6-28for more information.
Capacities and Specications
ApplicationCapacities
English Metric
Air Conditioning Refrigerant (R134a)
Front A/C
Front and Rear A/C2.3 lbs.
3.0 lbs.1.0 kg
1.4 kg
Cooling System
Without Rear Heater
With Rear Heater13.5 quarts
16.5 quarts12.8 L
15.6 L
Differential Fluid
Front Axle
Rear Axle2.6 pints
3.5 pints1.2 L
1.7 L
Engine Oil with Filter 4.5 quarts 4.3 L
Fuel Tank 27.0 gallons 101.8 L
5-107

Capacities and Specications (cont’d)
ApplicationCapacities
English Metric
Transmission Fluid (Drain and Rell) 5.0 quarts 4.7 L
Wheel Nut Torque 140 ft lb 190Y
All capacities are approximate. When adding, be sure to ll to the appropriate level, as recommended in this
manual. Recheck the uid level after lling. See refrigerant charge label under the hood for charge capacity
information and requirements.
Engine Specications
Engine RPO Transmission Spark Plug Gap Firing Order
“Vortec” 4300 V6 MFI* LU3 Automatic0.060 inches
(1.52 mm)1–6–5–4–3–2
*Micro Fuel Injection
5-108

❑Replace fuel lter.An Emission Control Service.
(See footnote †.)
❑Replace engine air cleaner lter. SeeEngine Air
Cleaner/Filter on page 5-21for more information.
An Emission Control Service.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
93,000 Miles (155 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
96,000 Miles (160 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
99,000 Miles (165 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission
Control Service.
❑Replace spark plugs.An Emission Control Service.
❑If you have not used your vehicle under severe
service conditions listed previously and, therefore,
have not changed your automatic transmission
uid, change both the uid and lter.
❑Change transfer case uid.
❑Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
❑Drain, ush and rell cooling system (or every
60 months since last service, whichever occurs rst).
SeeEngine Coolant on page 5-26for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test cooling system and
pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.
An Emission Control Service.
6-15

When doing frequent trailer towing.
Uses such as found in taxi, police or
delivery service.
If you do not use your vehicle under any of these
conditions, change the uid and lter every
50,000 miles (83 000 km).
❑Replace fuel lter.An Emission Control Service.
(See footnote †).
❑Replace engine air cleaner lter. SeeEngine Air
Cleaner/Filter on page 5-21for more information.
An Emission Control Service.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +).
97,500 Miles (162 500 km)
❑Change engine oil and lter (or every
12 months, whichever occurs rst).
An Emission Control Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs rst).(See footnote #).
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +).
100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission
Control Service.
❑Replace spark plugs.An Emission Control Service.
❑If you have not used your vehicle under severe
service conditions listed previously and, therefore,
have not changed your automatic transmission uid,
change both the uid and lter.
❑Change transfer case uid.
❑Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
❑Drain, ush and rell cooling system (or every
60 months since last service, whichever occurs rst).
SeeEngine Coolant on page 5-26for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.
An Emission Control Service.
6-21

Part C: Periodic Maintenance
Inspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall).You should let your dealer’s
service department do these jobs. Make sure any
necessary repairs are completed at once.
Proper procedures to perform these services may be
found in a service manual. SeeService Publications
Ordering Information on page 7-12.
Steering, Suspension and Front
Drive Axle Boot and Seal Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook-up, binding, leaks,
cracks, chang, etc. Clean and then inspect the
drive axle boot seals for damage, tears or leakage.
Replace seals if necessary.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out-of-position parts as well as open seams,
holes, loose connections or other conditions which
could cause a heat build-up in the oor pan or could let
exhaust fumes into the vehicle. SeeEngine Exhaust
on page 2-29.
Fuel System Inspection
Inspect the complete fuel system for damage or leaks.
Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
6-26