Page 261 of 392

yellowblue
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.
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.
Engine Cover
Removing the Engine Cover
1. Move both front seats as far back as they will go.
Page 266 of 392

yellowblue
6-20
Make sure the fresh air hose is still attached after the
filter change.
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.
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yellowblue
6-27
Thermostat
Engine coolant temperature is controlled by a thermostat
in the engine coolant system. The thermostat stops the
flow of coolant through the radiator until the coolant
reaches a preset temperature.
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see ªEngine Overheatingº in
the Index.A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:
Give freezing protection down to
-34F (-37C).
Give boiling protection up to 265F (129C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
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.
Page 274 of 392

yellowblue
6-28 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.
CAUTION:
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 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.
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the 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.
NOTICE:
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.
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6-34
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
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.
Some driving conditions or climates may cause a brake
squeal when the brakes are first applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly torque wheel nuts in the
proper sequence to GM specifications.
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6-69
Normal Maintenance
Replacement Parts
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing, and are subject to change. If a part listed in this
manual is not the same as the part used in your vehicle
when it was built, or if you have any questions, please
contact your GM truck dealer.
Engine Oil Filter AC Type PF52. . . . . . . . . . . . . . . .
Air Cleaner AC Type A1163C. . . . . . . . . . . . . . . . . . .
Positive Crankcase Ventilation
(PCV) Valve AC Type CV769C. . . . . . . . . . . . . . . .
Spark Plugs AC Type 41
-932 . . . . . . . . . . . . . . . . . . .
Spark Plug Gap 0.060 inches (1.52 mm). . . . . . . . . .
Fuel Filter AC Type GF481. . . . . . . . . . . . . . . . . . . . .
Thermostat GM Part No. 12559051. . . . . . . . . . . . . . .
Wiper Blades (Front) Trico 22110158, Pin Type. . . . .
18 inches (45.7 cm) Length
Wiper Blade (Rear)
Trico 22154396, Pin Type
14 inches (35.5 cm) Length
Vehicle Dimensions*
Length 189.8 inches (482 cm). . . . . . . . . . . . . . . . . . .
Width 77.5 inches (196.8 cm). . . . . . . . . . . . . . . . . . .
Height 76.0 inches (193.0 cm). . . . . . . . . . . . . . . . . . .
Wheelbase 111.0 inches (281.9 cm). . . . . . . . . . . . . .
Front Tread Width 65.1 inches (165.4 cm). . . . . . . . .
Rear Tread Width 65.1 inches (165.4 cm). . . . . . . . . .
*Figures reflect base equipment only.
Page 321 of 392

Scheduled Maintenance
yellowblue
7-5
Short Trip/City Definition
Follow the Short Trip/City Scheduled Maintenance if
any one of these conditions is true for your vehicle:
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 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 Service (or 3 months, whichever occurs first).
Every 6,000 Miles (10 000 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.
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (normal conditions).
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection. Fuel Tank, Cap and
Lines Inspection.
Page 322 of 392
Scheduled Maintenance
yellowblue
7-6
Short Trip/City Intervals
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).
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
Long Trip/Highway Definition
Follow this scheduled maintenance only if none of the
conditions from the Short Trip/City Scheduled
Maintenance is 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 causes engine oil to break
down slower.