Page 263 of 404
When to Add Oil
If the oil is at or below the ADD mark, then you'll need
to add some oil. But you must use the right kind. This
part explains what kind
of oil to use. For crankcase
capacity, see "Capacities and Specifications"
in the Index
NOTICE:
Don't add too much oil. If your engine has so
much oil that the oil level gets above the upper
mark that shows the proper operating range,
your engine could be damaged.
The engine oil fill cap
for the 4.3L, S.OL and the
S.7L engine is located on
the driver's side engine
valve cover.
The engine oil
fill cap for the 7.4L engine is located at
the front
of the engine.
Just fill it enough to put the level somewhere in the
proper operating range. Push the dipstick all the way
hack in when you're through.
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What Kind of Oil to Use
Oils recommended for your vehicle can be identified by
looking for the “Starburst” symbol. This symbol
indicates that the
oil has been certified by the American
Petroleum Institute
(API). Do not use any oil which
does not carry this Starburst symbol.
If you change your own oil,
be sure you use oil that has
the Starburst symbol on the
front of
the oil container.
If you have your oil changed for you, be sure the oil put
into your engine is American Petroleum Institute
certified for gasoline engines.
You should also use the proper viscosity oil for your
vehicle, as shown
in the following chart:
RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS ~~ . . - . . -.
FOR BEST FUEL E Y AND COLD STARTING, SELECT THE LOWEST
~ ~~~ ~ ~
SAE VISCOSITY Gnnvr ulL FOR THE EXPECTED TEMPERATURE RANGE.
HOT
WEATHER
C
I +3*
+ 27
i SAE SW-30
’I PREFERRED
LOOK
FOR THIS
SYMBOL
COLD
WEATHER
DO NOT USE SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED
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As shown in the chart, SAE 5W-30 is best for your
vehicle. However,
you can use SAE low-30 if it’s going
to be
0°F (-1 8°C) or above. These numbers on an oil
container show its viscosity, or thickness. Do not use
other viscosity oils, such as
SAE 20W-50.
I NOTICE:
Use only engine oil with the American Petroleum
Institute Certified For Gasoline Engines
“Starburst” 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.
Engine Oil Additives
Don’t add anything to your oil. Your GM dealer is ready
to advise if you think something should be added.
When to Change Engine Oil
See if any one of these is true for you:
a
a
a
a
a
Most trips are less than 5 to 10 miles (8 to I6 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.
If none of them is true, change the oil and filter every
7,500 miles ( 12 500 km) or I2 months -- whichever
occurs first. Driving a vehicle
with a fully warmed
engine under highway conditions causes engine
oil to
break down slower.
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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.
Air Cleaner
Your air cleaner is located between the battery and
coolant recovery tank.
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Page 269 of 404
Automatic Transmission Fluid
When to Check a1 C’ -ge
A good time to check your auromarlc transmission fluid
level
is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles
(83 000 km) if the vehicle’s GVWR is over 8,600 or
if the vehicle is mainly driven under one or more of
these conditions:
In heavy city traffic where the outside temperature
regularly reaches
90°F (32°C) or higher.
0 In hilly or mountainous terrain.
0 When doing frequent trailer towing.
Uses such as found in taxi, police or delivery service.
If your vehicle’s GVWR is not over 8,600 and you do
not use your vehicle under any of these conditions, the
fluid and filter
do not require changing.
See “Scheduled Maintenance Services’’
in the Index.
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 on the dipstick.
NOTICE:
Too much or too little fluid can damage your
transmission.
Too much can mean that some of
i 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.
Wait at least 30 minutes before checking the
transmission fluid level
if you have been driving:
When outside temperatures are above 90°F (32°C).
0 At high speed for quite a while.
In heavy traffic -- especially in hot weather.
While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which
is 180°F to 200°F (82°C
to 93°C).
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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.
II
Check the fluid level only when your engine is off, the
vehicle
is parked on a level place and the transmission
is cool enough for you to rest your fingers on the
transmission case.
Then, follow these steps:
1. Remove the filler plug.
2. Check that the lubricant level is up to the bottom of
the filler plug hole.
3. If the fluid level is good, install the plug and be sure
it is fully seated. If the fluid level is low, add more
fluid as described in the next steps.
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A 50/50 mixture of water and the proper coolant for
your vehicle
will:
Give freezing prorecrlon down to -34°F (-37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning gages work as they should.
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. use
a mixture
of one-half dum wwter (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. 363462 1 ) with any complete coolant change. If you
use this mixture.
you don’t need to add anything else.
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
50150 mix of clean
water and
DEX-COOL TM (orange-colored,
silicate-free) antifreeze.
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NOTICE:
0
0
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 &‘Appearance Care”
in
the Index.
Brake Wear
If you have a C 3500 HD model, it has four-wheel
disc 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).
A’ CAUTION:
I
The brake wear warning sound means that
sooner or later your brakes won’t work well.
That could lead to an accident. When you hear
the brake wear warning sound, have your vehicle serviced.
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