1999 CHEVROLET S10 service

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6-14
As shown in the chart, SAE 5W-30 is best for your
vehicle. However, you can use SAE 10W
-30 if it's going
to be 0F (
-18C) or above. These numbers on an oil
container show its viscosity, or thickness. Do not use
other viscosity oils, such as SAE 20W
-50.
NOTICE:
Use only engine oil with the American Petroleum
Institute Certified For Gasoline Engines
ªStarburstº symbol. Failure to use the
recommended oil can result in engine damage
not covered by your warranty.
GM Goodwrench oil meets all the requirements for
your vehicle.
If you are in an area where the temperature falls below
-20F (-29C), consider using either an SAE 5W-30
synthetic oil or an SAE 0W
-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Don't add anything to your oil. Your dealer is ready to
advise if you think something should be added.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:

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).

You operate your vehicle in dusty areas or
off
-road frequently.

You frequently tow a trailer.

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 filter
every 3,000 miles (5 000 km) or 3 months
-- whichever
occurs first.

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6-15
If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months
-- whichever
occurs first. Driving a vehicle with a fully warmed
engine under highway conditions causes engine oil to
break down slower.
Remote Oil Filter (Four
-Wheel Drive)
The access door for the
remote oil filter is in the
steering linkage shield
assembly located under
the radiator support.
Twist the screw to unlock
or lock the door. Make
sure if you open the door,
it is securely closed
when you are finished.
What to Do with Used Oil
Did you know that 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 throw
away 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 real threat to the environment. If you
change your own oil, be sure to drain all free
-flowing oil
from the filter before disposal. Don't ever 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.

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Refer to the Maintenance Schedule to determine when to
replace the air filter. See ªScheduled Maintenance
Servicesº in the Index.
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can cause a
damaging engine fire. And, dirt can easily get into
your engine, which will damage it. Always have the
air cleaner/filter in place when you're driving.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 15,000 miles
(25 000 km) if the vehicle is mainly driven under one or
more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.

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 fluid and filter every
50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at the dealership
service department.

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6-20 How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. See ªRecommended
Fluids and Lubricantsº in the Index.
Add fluid only after checking the transmission fluid while it
is hot. (A cold check is used only as a reference.) If the fluid
level is low, add only enough of the proper fluid to bring the
level up to the HOT area for a hot check. It doesn't take much
fluid, generally less than one pint (0.5 L). Don't overfill.
NOTICE:
We recommend you use only fluid labeled
DEXRON-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than
DEXRON
-III is not covered by your new
vehicle warranty.

After adding fluid, recheck the fluid level as
described under ªHow to Check.º

When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, the fluid in your manual
transmission doesn't require changing.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at your GM dealership
Service Department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire. Be
sure to get an accurate reading if you check your
transmission fluid.

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6-22 When to Check and What to Use
Refer to the Maintenance Schedule, Owner Checks and
Services, to determine how often you should check the
fluid level in your clutch master cylinder reservoir and
for the proper fluid. See ªOwner Checks and Servicesº
and ªRecommended Fluids and Lubricantsº in
the Index.
How to Check
The proper fluid should be added if the level does not
reach the bottom of the diaphragm when it's in place in
the reservoir. See the instructions on the reservoir cap.
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
ªScheduled Maintenance Servicesº in the Index.

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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.
Use care not to overtighten plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Front 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
ªScheduled Maintenance Servicesº in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you may need to add some lubricant.

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NOTICE:

Using the wrong fluid can badly damage
brake system parts. For example, just a few
drops of mineral
-based oil, such as engine
oil, in your brake system can damage brake
system parts so badly that they'll have to be
replaced. Don't let someone put in the
wrong kind of fluid.

If you spill brake fluid on your vehicle's
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on your vehicle. If you do, wash it off
immediately. See ªAppearance Careº in
the Index.
Brake Wear
If you have four-wheel drive, your vehicle has
four
-wheel disc brakes. If not, your vehicle has front
disc brakes and rear drum 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 firmly).
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.

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Battery
Your new vehicle comes with an ACDelco Freedom

battery. When it's time for a new battery, we recommend
an ACDelco Freedom battery. Get one that has the
replacement number shown on the original battery's label.
Vehicle Storage
If you're not going to drive your vehicle for 25 days or more,
remove the black, negative (
-) cable from the battery. This
will help keep your battery from running down.
CAUTION:
Batteries have acid that can burn you and gas
that can explode. You can be badly hurt if you
aren't careful. See ªJump Startingº in the Index
for tips on working around a battery without
getting hurt.
Contact your dealer to learn how to prepare your vehicle
for longer storage periods.
Also, for your audio system, see ªTheft
-Deterrent
Featureº in the Index.
Bulb Replacement
Before you replace any bulbs, be sure that all the lamps
are off and the engine isn't running. See ªReplacement
Bulbsº in the Index.
For any bulb changing procedure not listed in this
section, contact your GM dealer's service department.
Halogen Bulbs
CAUTION:
Halogen bulbs have pressurized gas inside and
can burst if you drop or scratch the bulb. You or
others could be injured. Be sure to read and
follow the instructions on the bulb package.