cooling CHEVROLET ASTRO 1996 User Guide

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.

How to Add Coolant to the Radiator
1. You can remove the
radiator pressure cap
when the cooling
system, including the
radiator pressure cap and
upper radiator hose, is
no longer hot. Turn the
pressure cap slowly
counterclockwise until it
first stops. (Don't press
down while turning the
If
you hear a hiss, wait for that to stop. A hiss means
there is still some pressure left.
I 2. Then keep turning
I ,the pressure cap, but
now push down as you
5-19

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 every day 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.
If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially if
you maintain your tires properly. If air goes
out of a tire, it’s much more likely to leak out slowly.
But if you should ever have a 4‘blowout,” here are a few
tips about what
to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well
out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use in a
skid.
In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by steering the way
you want the vehicle to go. It may be
very bumpy and noisy, but
you can still steer. Gently
brake
to a stop -- well off the road if possible.
If a tire goes flat, the next part shows how to
use your
jacking equipment to change a flat tire safely.
5-22

What to Use Rear Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when
to change it. See
“Scheduled Maintenance Services” in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you’ll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole. Refer
to the Maintenance Schedule to determine what
kind of lubricant
to use. See “Recommended Fluids and
Lubricants” in the Index.
Engine Coolant
The cooling system in your vehicle is filled with new
DEX-COOL (orange-colored, silicate-free) engine
coolant. This coolant is designed to remain in your
vehicle for
5 years or 100,000 miles (166 000 km),
whichever occurs first.
The following explains your cooling system and how to
add coolant when it is low. If
you have a problem with
engine overheating, see “Engine Overheating’’ in
the Index.
A 50/50 mixture of water and the proper coolant for
your vehicle will:
0 Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 265 “F (1 29°C).
0 Protect against rust and corrosion.
Help keep the proper engine temperature.
0 Let the warning lights and gages work as
they should.
6-25

NOTICE:
When adding coolant it is important that you use
DEX-COOL
TM (orange-colored, silicate-free)
coolant meeting
GM Specification 6277M.
If silicated coolant 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.
What to Use
Use a mixture
of one-half clean water (preferably
distilled) and one-half
DEX-COOL (orange-colored,
silicate-free) antifreeze that meets GM Specification
6277M, which won’t damage aluminum parts. Use GM
Engine Coolant Supplement (sealer)
(GM Part
No. 3634621) with any complete coolant change. If you
use this mixture, you don’t need to add anything else.
A CAUTION:
I
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mix will. Your vehicle’s coolant warning
system is set for the proper coolant mix. With
plain water or the wrong mix, 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 mix of clean
water and DEX-COOL (orange-colored,
silicate-free) antifreeze.
6-26

NOTICE:
If you use an improper coolant mix, your engine
could overheat and be badly damaged. The repair
cost wouldn’t be covered by your warranty. Too
much water in the mix can freeze and crackthe
engine, radiator, heater core and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
I NOTICE: I
If you use the proper coolant, you don’t have to
add extra inhibitors or additives which claim
to
improve the system. These can be harmful.
Checking Coolant
When your engine is cold, the coolant level should be at
ADD, or a little higher. When your engine is warm, the
level should be up to
FULL HOT, or a little higher.
6-27

If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new
GM original
equipment
parts. This way, you will be sure to have
the right wheel, wheel bolts and wheel nuts for your
vehicle model.
~ -.
’
Using 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 whee1,’wheel bolts and wheel nuts
for replacement.
-- I--
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” in the Index for
more information.
Used Replacement Wheels
A
/! CAUTION: ..
I
Putting a used wheel on your vehicle is
dangerous. You can’t know how
it’s been used or
how many miles it’s been driven.
It could fail
suddenly and cause an accident.
If you have to
replace
a wheel, use a new GM original
equipment wheel.
6-48

Capacities and Specifications
Engine Specifications
Engine ............... “VORTEC” 4300 V6 SFI‘k
RPO ................................... L35
Firing Order
...................... 1-6-5-4-3-2
Horsepower
................... 190 at 4,400 rpm
Thermostat Specification
......... 195 “F (9 1 O C)
“Sequential Fuel Injection
Wheel Nut Torque
Base or Optional Wheel ....... 100 lb-ft (140 Nem)
Tire Pressures ......... .... See “Loading
Your Vehicle” in
the Index.
Cooling System Capacity
Quantity*
Without Rear Heater
13.5 quarts (12.8 L)
Quantity*
with Rear Heater
16.5 quarts (15.5 L)
*All quantities are approximate. After refill, the level must
be checked.
Crankcase Capacity
Quantity*
with Filter
................... 4.5 quarts (4.3 L)
*All quantities are approximate. After refill, the level
must be checked. Do not overfill.
Fuel Tank Capacity
Standard Tank* ...........
*All quantities are approximate,
Transmission Capacity
Automatic Transmission
(Drain and Refill)“
.........
*All quantities are approximate.
Rear Axle Capacity
Standard Rear Axle* . .
Locking Rear Axle” ..........
*All quantities are approximate.
. . 27 gallons (102 L)
. . 5.0 quarts (4.7 L)
. . 3.5 pint (1.7 L)
3.5 pint (1.7 L)
6-67

Maintenance Schedule
Short TripKity Definition
Follow the Short TripKity Maintenance Schedule if any
one
of these conditions is true for your vehicle:
0
0
0
0
0
Most trips are less than 5 to 10 miles (8 to 16 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).
Most trips are through dusty areas.
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 yo~l should follow this schedule if
you operate your vehicle under any of these conditions
is
that these conditions cause engine oil to break
down soonex
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 Service (or
3 months, whichever occurs fust).
At 6,000 Miles (10 000 km) -- Then Every
12,000 Miles
(20 000 km): Tire Rotation.
Every 15,000 Miles (25 000 km): Air Cleaner Filter
Inspection,
if driving in dusty conditions. Front
Wheel Bearing Repack (2WD only) (or at each brake
relining, whichever occurs first). Automatic
Transmission Service (severe conditions only).
Every 30,000 Miles (50 000 km): Air Cleaner Filter
Replacement.
Fuel Filter Replacement. Automatic
Transmission Service (Normal Conditions).
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection. Fuel
Tank, Cap and Lines Inspection.
Every 100,000 Miles (166 000 km): Cooling System
Service (or every
60 months, whichever occurs first).
Spark Plug Wire Inspection. Spark Plug Replacement.
Positive Crankcase Ventilation (PCV) Valve Inspection.
These intervals only summarize nzaintenance services.
Be sure to follow the complete maintenance schedule on
the following pages.
7-4

Maintenance Schedule
Long Tripmighway Definition Long Trip/Highway Intervals
Follow this maintenance schedule only if none of the
conditions from the Short Trip/City Maintenance
Schedule is true.
Driving a vehicle with nf.lly warmed engine under
highway conditions causes engine oil to break
down sloweE
Every 7,500 Miles (12 500 km): Engine Oil and Filter
Char,ge (or every 12 months, whichever occurs first).
Chassis Lubrication (or every 12 months, whichever
occurs first). Drive Axle Service.
At 7,500 Miles (12 500 km) -- Then Every
15,000 Miles
(25 000 km): 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. Air Cleaner Filter Replacement. Front
Wheel Bearing Repack (2WD only)
(or at each brake
relining, whichever occurs first). Automatic
Transmission Service (Normal Conditions).
Accessory Drive Belt Inspection.
Fuel Tank,
Cap and Lines Inspection.
Every 100,000 Miles (166 000 km): Cooling System
Service (or every
60 months, whichever occurs first).
Spark Plug Wire Inspection. Spark Plug Replacement.
Positive Crankcase Ventilation (PCV) Valve Inspection.
These intervals only swnnzarize maintenance services.
Be sure to
follow the complete maintenance schedule on
the following pages.
Every 60,000 Miles (100 000 km): Engine
7-5