Page 249 of 388

I RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS
FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST
I SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE.
HOT
WEATHER
+loo- ~
+ 80- -
+60- -
+40- -
+20- -
0- -
-7
-18 --
SAE 5W PREFER ~
COLD
WEATHER
LOOK
FOR THIS
SYMBOL
DO NOT USE SAE 2OW-50 OR ANY OTHER
GRADE OIL NOT RECOMMENDED
L
1-30 REO
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 (- 18 "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.
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.
If you are in an area where the temperature falls below
-20°F (-29"C), consider using either an SAE 5W-30
synthetic oil or an SAE OW-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
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Page 250 of 388

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
If any one of these is true for you, use the short tripkity
maintenance schedule:
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.
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, use the long
trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (1 2 500 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
,! I!
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.
k
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Page 252 of 388

Operating the engine with the air cleaner 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 off.
NOTICE:
If the air cleaner 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 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
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.
In hilly or mountainous terrain.
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.
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Page 256 of 388

Rear Axle Engine Coolant
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.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See “Recommended Fluids and
Lubricants” in
the Index. The cooling
s stem in your vehicle
is filled with
DEX-COOL
8 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 sysre~ 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 DEX-COOL’ coolant will:
0 Give freezing protection down to -34°F (-37°C).
0 Give boiling protection up to 265 “F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
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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.
What to Use
Use a mixture of one-half clean water (preferably
distilled) and one-half
DEX-COOL@ coolant which
won’t damage aluminum parts.
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
50/50 mix of clean
water and DEX-COOL@ coolant.
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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
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).
,
I
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
I
warning sound, have your vehicle serviced. I
I I
I NOTICE:
Continuing to drive with worn-out brake pads
could result in costly brake repair.
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Page 298 of 388

Name
RH-HIBM
ECM-I
HORN
LH-HDLP
LH-HIBM
FUEL SOL
IGN-E
ECM-B
Circuits Protected
Right-hand High-beam Headlamp
(Export Only)
Ignition Coil, Crankshaft Position Sensor, VCM, Fuel Injectors,
Coil Driver
Horn Relay, Underhood Lamp(
s)
Left-hand Headlamp
(Export Only)
Left-hand High-beam Headlamp
(Export Only)
PCM, Fuel Solenoid Driver,
Engine Shutoff Solenoid
Air Conditioning Clutch Relay
Fuel Pump Relay, VCM, PCM,
Fuel Pump and Engine Oil
Pressure Switch
Capacities and Specifications
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.
These specifications
are for information only. If you
have
any questions, see the service manual for the
chassis or refer to the body manufacturer’s publications.
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Crankcase Capacity
ENGINE VIN Quantity With Filter
“VORTEC”4300 W 4.5 Quarts (4.3 L)
“VORTEC”5000
“VORTEC”5700
“VORTEC”7400 M
R
J
5 Quarts (4.8 L)
5 Quarts (4.8 L)
7 Quarts (6.5 L)
Fuel Tank Capacity
TYPE QUANTITY
Standard Tank 3 1 Gallons (1 17.33 L)
Optional Tank* * 55 Gallons (208.18 L)
*All quantities are approximate.
** 159’’ , 177” Wheelbase Vehicles Only.
All quantities are approximate. After refill, the level MUST be checked as outlined
under “Engine Oil And Filter Recommendations’’ in
Section
5.
**Add one additional quart for RPO 5Z1 and
WO KL5 Models.
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