AIR CHEVROLET ASTRO 2000 Workshop Manual

4-36 Trailer Brakes
If your trailer weighs more than 1,000 lbs. (450 kg)
loaded, then it needs its own brakes
-- and they must be
adequate. Be sure to read and follow the instructions for
the trailer brakes so you'll be able to install, adjust and
maintain them properly.
Your trailer brake system can tap into your vehicle's
hydraulic brake system, except:

Don't tap into your vehicle's brake system if the
trailer's brake system will use more than 0.02 cubic
inch (0.3 cc) of fluid from your vehicle's master
cylinder. If it does, both braking systems won't work
well. You could even lose your brakes.

Will the trailer parts take 3,000 psi (20 650 kPa) of
pressure? If not, the trailer brake system must not be
used with your vehicle.

If everything checks out this far, then make the brake
fluid tap at the port on the master cylinder that sends
fluid to the rear brakes. But don't use copper tubing
for this. If you do, it will bend and finally break off.
Use steel brake tubing.
Driving with a Trailer
CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You can't see
or smell CO. It can cause unconsciousness or
death. (See ªEngine Exhaustº in the Index.)
To maximize your safety when towing a trailer:

Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.

Keep the rear
-most windows closed.

If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
MAX A/C because it only recirculates the
air inside your vehicle. (See ªComfort
Controlsº in the Index.)

4-40 Trailer Wiring Harness
If you have the optional trailering package, your vehicle
will have an eight
-wire harness, including the center
high
-mounted stoplamp battery feed wire. The harness
is stored on the passenger's side of the vehicle near
the rear wheel well. This harness has a 30 amp battery
feed wire and no connector, and should be wired by
a qualified electrical technician. After choosing an
aftermarket trailer mating connector pair, have the
technician attach one connector to the eight
-wire trailer
harness and the other connector to the wiring harness
on the trailer. Be sure the wiring harness on the trailer is
taped or strapped to the trailer's frame rail and leave it
loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. The eight
-wire
harness must be routed out of your vehicle between the
rear door and the floor, with enough of the harness left
on both sides so that the trailer or the body won't pull it.
If you do not have the optional trailering package, your
vehicle will still have a trailering harness. The harness is
located near the passenger's side rear wheel well. It
consists of six wires that may be used by after
-market
trailer hitch installers. The technician can use the following color code chart
when connecting the wiring harness to your trailer.

Brown: Rear lamps.

Yellow: Left stoplamp and turn signal.

Dark Green: Right stoplamp and turn signal.

White (Heavy Gage): Ground.

Light Green: Back
-up lamps.

White (Light Gage): Center
High
-Mounted Stoplamp.

Blue: Auxiliary circuit (eight
-wire harness only).

Orange: Fused auxiliary (eight
-wire harness only).
Store the harness in its original place. Wrap the
harness together and tie it neatly so it won't
be damaged.

5-4
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P).
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off all lamps
that aren't needed as well as radios. This will avoid
sparks and help save both batteries. In addition, it
could save your radio!
NOTICE:
If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
4. Open the hoods and locate the batteries. Find
the positive (+) and negative (
-) terminals on
each battery.
CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
Be sure the battery has enough water. You don't
need to add water to the ACDelco
battery
installed in every new GM vehicle. But if a
battery has filler caps, be sure the right amount
of fluid is there. If it is low, add water to take care
of that first. If you don't, explosive gas could
be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.

5-8 If Steam Is Coming From Your Engine
CAUTION:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Just turn it off and get everyone away
from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before you
open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop your engine if
it overheats, and get out of the vehicle until the
engine is cool.
NOTICE:
If your engine catches fire because you keep
driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not be
covered by your warranty.

5-9 If No Steam Is Coming From Your Engine
If you get an engine overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:

Climb a long hill on a hot day.

Stop after high
-speed driving.

Idle for long periods in traffic.

Tow a trailer. See ªDriving on Gradesº in the Index.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If you have an air conditioner and it's on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D) for automatic transmissions.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, 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 vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.

5-18
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.
If a Tire Goes Flat
It's unusual for a tire to ªblow outº 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 ªblowout,º 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.

5-30
CAUTION:
Incorrect wheel nuts or improperly tightened
wheel nuts can cause the wheel to become loose
and even come off. This could lead to an accident.
Be sure to use the correct wheel nuts. If you have
to replace them, be sure to get new GM original
equipment wheel nuts.
Stop somewhere as soon as you can and have
the nuts tightened with a torque wrench to
100 lb
-ft (140 N´m).
NOTICE:
Improperly tightened wheel nuts can lead to
brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque specification.
13. Remove the wheel blocks.
NOTICE:
Wheel covers won't fit on your compact spare.
If you try to put a wheel cover on your compact
spare, you could damage the cover or the spare.

5-32
5. Make sure the tire is stored securely. Push, pull, and
then try to rotate or turn the tire. If the tire moves,
use ratchet/wheel wrench to tighten the cable.
Return the jacking equipment to its proper location.
Compact Spare Tire
Although the compact spare tire was fully inflated
when your vehicle was new, it can lose air after a time.
Check the inflation pressure regularly. It should be
60 psi (420 kPa).
After installing the compact spare on your vehicle, you
should stop as soon as possible and make sure your
spare tire is correctly inflated. The compact spare is
made to perform well at speeds up to 65 mph
(105 km/h) for distances up to 3,000 miles (5 000 km),
so you can finish your trip and have your full
-size tire
repaired or replaced where you want. Of course, it's best
to replace your spare with a full
-size tire as soon as you
can. Your spare will last longer and be in good shape in
case you need it again.

6-
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel
6
-5 Filling Your Tank
6
-7 Filling a Portable Fuel Container
6
-8 Checking Things Under the Hood
6
-11 Engine Oil
6
-15 Engine Cover
6
-19 Engine Air Cleaner/Filter
6
-20 Automatic Transmission Fluid
6
-24 All-Wheel Drive
6
-25 Rear Axle
6
-26 Engine Coolant
6
-29 Radiator Pressure Cap
6
-30 Power Steering Fluid
6
-31 Windshield Washer Fluid
6
-32 Brakes6
-35 Battery
6
-36 Bulb Replacement
6
-42 Windshield Wiper Blade Replacement
6
-43 Tires
6
-51 Appearance Care
6
-51 Cleaning the Inside of Your Vehicle
6
-54 Cleaning the Outside of Your Vehicle
6
-56 Cleaning Tires
6
-57 Finish Damage
6
-57 Underbody Maintenance
6
-58 GM Vehicle Care/Appearance Materials
6
-59 Vehicle Identification Number (VIN)
6
-59 Service Parts Identification Label
6
-60 Electrical System
6
-68 Capacities and Specifications
6
-69 Normal Maintenance Replacement Parts

6-2
Service
Your dealer knows your vehicle best and wants you to
be happy with it. We hope you'll go to your dealer for
all your service needs. You'll get genuine GM parts and
GM
-trained and supported service people.
We hope you'll want to keep your GM vehicle all GM.
Genuine GM parts have one of these marks:
Doing Your Own Service Work
If you want to do some of your own service work, you'll
want to use the proper service manual. It tells you much
more about how to service your vehicle than this manual
can. To order the proper service manual, see ªService
and Owner Publicationsº in the Index.
Your vehicle has an air bag system. Before attempting
to do your own service work, see ªServicing Your Air
Bag
-Equipped Vehicleº in the Index.
You should keep a record with all parts receipts and
list the mileage and the date of any service work you
perform. See ªMaintenance Recordº in the Index.