cooling CHEVROLET ASTRO 2003 User Guide

If there seems to be no leak, start the engine again. How to Add Coolant to the Coolant
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
Recovery Tank
down. If it doesn’t, your vehicle needs service. Turn off If you haven’t found a problem yet, but the coolant level
the engine. isn’t at the
ADD mark, add a 50/50 mixture of clean
Nofice: Engine damage from running your engine
without coolant isn’t covered by your warranty.
Notice: When adding coolant, it is important that
you use only
DEX-COOL@ (silicate-free) coolant.
If coolant other than DEX-COOL@’ is added to the
system, premature engine, heater core or radiator
corrosion may result.
In addition, the engine coolant
will require change sooner
- at 30,000 miles
(50 000 km) or 24 months, whichever occurs first.
Damage caused by the use of coolant other than
DEX-COOL@ is not covered by your new vehicle
warranty.
drinkable wafer, and DEX-COOL@ engine coolant at
the coolant recovery tank. See
Engine Coolant on
page 5-28 for more information.
Adding only p.,,n water to your coG...rg
system can be dangerous. Plain water, or
some other
liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system
is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot but you wouldn’t get the overheat warning.
Your engine could catch fire and you or others
could be burned. Use a
50/50 mixture of clean,
drinkable water and DEX COOL@ coolant.
5-34

If the overheat warning continues, there’s one more
thing you can try.
You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before you do it.
1
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and
if you turn the radiator
pressure cap
- even a little - they can come
out at high speed. Never turn the cap when
the
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have
to
turn the pressure cap.
5-36

How to Add Coolant to the Radiator
You can remove the
radiator pressure cap
when the cooling system,
including the radiator
pressure cap and
upper radiator hose,
is no longer hot.
1. Turn the pressure cap slowly counterclockwise until
it first stops. (Don't press down while turning the
pressure cap.)
2. Then keep turning the pressure cap, but now
push down as you
turn it. Remove
the pressure cap.
If you hear a hiss, wait for that
to stop. A hiss
means there is still some pressure left.
5-37

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
filler neck may be lower.
If the level is lower, add
more of the proper
DEX-COOL@ coolant mixture
through the filler neck until the level reaches
the base of the filler neck.
Then replace the pressure cap. At any time during
this procedure
if coolant begins to flow out of
the filler 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.
5-39

Wheel Alignment and Tire Balance If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new
GM
The wheels on your vehicle were aligned and balanced original
equipment parts. This way, you will be sure to
carefully at the factory to give you the longest tire life have
the right wheel, wheel bolts and wheel nuts for
and best overall performance.
your
vehicle.
Scheduled wheel alignment and wheel balancing are
not needed. However,
if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need to be reset.
If you notice your vehicle
vibrating when driving on a smooth road, your wheels
may need to be rebalanced.
Wheel Replacement
Replace any wheel that is bent, cracked or badly
rusted or corroded.
If wheel nuts keep coming loose,
the wheel, wheel bolts and wheel nuts should be
replaced. If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer
if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces. the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous.
It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision
in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.
Notice: The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and tire or tire chain clearance to the body and chassis.
See
Changing a Flat Tire on page 5-71 for more
information.
-~
5-69

Section 6 Maintenance Schedule
Maintenance Schedule ............................... 6.2
Introduction
................................................... 6.2
Your Vehicle and the Environment
.................... 6-2
Maintenance Requirements
.............................. 6-2
How This Section
is Organized ......................... 6-3
Part
A: Scheduled Maintenance Services ........... 6.4
Using Your Maintenance Schedule
.................... 6.4
Selecting the Right Schedule
........................... 6-5
Short Trip/City Scheduled Maintenance
.............. 6.7
Long Trip/Highway Scheduled Maintenance
...... 6.18
Part B: Owner Checks and Services
................ 6.26
At Each Fuel Fill
.......................................... 6-26
At Least Once a Month
................................. 6.26
At Least Twice a Year
................................... 6.26 At
Least Once a Year
................................... 6-27
Part C: Periodic Maintenance inspections
......... 6.30
Steering. Suspension and Front Drive Axle
Boot and Seal Inspection
............................ 6.30
Exhaust System Inspection
............................ 6.30
Fuel System Inspection
.................................. 6.30
Engine Cooling System Inspection
................... 6.30
Throttle System Inspection
............................ -6-31
Transfer Case and Front Axle
(All-Wheel Drive) Inspection
....................... -6-31
Brake System Inspection
................................ 6.31
Part D: Recommended Fluids
and Lubricants
.......................................... 6.32
Part E: Maintenance Record
........................... 6.34
6-
1

Selecting the Right Schedule
First you’ll need to decide which of the two schedules
is right for your vehicle. Here’s how to decide which
schedule to follow:
Short Trip/City Definition
Follow the Short Trip/City Scheduled Maintenance if any
one of these conditions is true for your vehicle:
e
e
e
e
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.
If the vehicle is used for delivery service, police,
taxi or other commercial application.
One of the reasons you should follow this schedule if
you operate your vehicle under any of these conditions
is that these conditions cause engine oil to break
down sooner.
Short Trip/City Intervals
Every 3,000 Miles (5 000 km): Engine Oil and Filter
Change (or
3 months, whichever occurs first). Chassis
Lubrication (or
3 months, whichever occurs first).
Drive Axle Fluid Check.
Every 6,000 Miles (IO 000 km): Tire Rotation.
Every 15,000 Miles (25 000 km): Engine Air
Cleaner Filter Inspection,
if driving in dusty conditions.
Front Wheel Bearing Repack (two-wheel drive only)
(or at each brake relining, whichever occurs first).
Automatic Transmission Service (severe conditions only).
Every 30,000 Miles (50 000 km): Engine Air Cleaner
Filter Replacement. Fuel Filter Replacement.
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (normal conditions).
Transfer Case Fluid Change.
Every 100,000 Miles (166 000 km): Spark Plug Wire
Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150,000 Miles (240 000 km): Cooling System
Service (or every
60 months, whichever occurs
first). Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
6-5

Long Trip/Highway Definition
Follow this scheduled maintenance only if none of
the conditions from the Short Trip/City Scheduled
Maintenance are true. Do not use this schedule
if the
vehicle is used for trailer towing, driven in a dusty area
or used
off paved roads. Use the Short Trip/City
schedule for these conditions.
Driving a vehicle with a fully warmed engine under
highway conditions will cause engine oil
to break
down slower.
Long Trip/Highway Intervals
Every 7,500 Miles (12 500 km): Engine Oil and Filter
Change (or every
12 months, whichever occurs first).
Chassis Lubrication (or
12 months, whichever
occurs first). Drive Axle Fluid Check. Tire Rotation.
Every 15,000 Miles (25 000 km): Automatic
Transmission Service (severe conditions only).
Every 30,000 Miles (50 000 km): Fuel Filter
Replacement. Engine Air Cleaner Filter Replacement.
Front Wheel Bearing Repack (two-wheel drive only)
(or at each brake relining, whichever occurs first).
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (normal conditions).
Transfer Case Fluid Change.
Every 100,000 Miles (166 000 km): Spark Plug Wire
Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150,000 Miles (240 000 km): Cooling System
Service (or every
60 months, whichever occurs first).
Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
6-6

100,000 Miles (166 000 km)
0 Inspect spark plug wires. An Emission Control
Service.
0 Replace spark plugs. An Emission Control Service.
0 If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmission fluid, change
both the fluid and filter.
0 Change transfer case fluid.
Cl Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
0 Drain, flush and refill cooling system (or every
60 months since last service, whichever occurs first).
See
Engine Coolant on page 5-28 for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test cooling system and
pressure cap.An
Emission Control Service.
An Emission Control Service.
Cl Inspect engine accessory drive belt.
Long Trip/Highway Scheduled
Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at
150,000 miles
(240 000 km) should be repeated at the same interval
after
150,000 miles (240 000 km) for the life of this
vehicle.
See
Part 5: Owner Checks and Services on page 6-26
and Part C: Periodic Maintenance Inspections on
page 6-30.
Footnotes
t The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
# Lubricate the front suspension, ball joints and kingpin
bushings, steering linkage and transfer case shift linkage,
parking brake cable guides and brake pedal springs.
+ A good time to check your brakes is during tire
rotation. See Brake System Inspection
on page 6-31.
6-1 8

97,500 Miles (162 500 km)
U Change engine oil and filter (or every 12 months,
0 Lubricate chassis components (or every 12 months,
0 Check readfront axle fluid level and add fluid as
whichever occurs first).
An Emission Control Service.
whichever
occurs first). (See footnote #).
needed. Check constant velocity joints and axle seals
for leaking.
page 5-64 for proper rotation pattern and additional
information.
(See footnote +).
0 Rotate tires. See Tire Inspection and Rotation on
100,000 Miles (166 000 km)
0 Inspect spark plug wires. An Emission Control
U Replace spark plugs. An Emission Control Service.
Service.
0 If you haven’t used your
vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmission fluid, change
both the fluid and filter.
150,000 Miles (240 000 km)
U Drain, flush and refill cooling system (or every
60 months since last service, whichever occurs first).
See
Engine Coolant on page 5-28 for what to use.
inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.
An Emission Control Service.
U Inspect engine accessory drive belt. An Emission
Control Service.
0 Change transfer case fluid.
0 Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
6-25