{CAUTION:
You can be burned if you spill coolant on
hot engine parts. Coolant contains
ethylene glycol and it will burn if the
engine parts are hot enough. Do not spill
coolant on a hot engine.
1. You can remove the
coolant surge tank
pressure cap when
the cooling system,
including the coolant
surge tank pressure
cap and upper
radiator hose, is no
longer hot.
Turn the pressure cap slowly counterclockwise
about one full turn. If you hear a hiss, wait
for that to stop. A hiss means there is
still some pressure left.2. Then keep turning the pressure cap slowly,
and remove it.
3. Fill the coolant surge tank with the proper
mixture, to the FULL COLD mark.
293
4. With the coolant surge tank pressure cap off,
start the engine and let it run until you can
feel the upper radiator hose getting hot. Watch
out for the engine cooling fan.
By this time, the coolant level inside the
coolant surge tank may be lower. If the level is
lower, add more of the proper mixture to the
coolant surge tank until the level reaches
slightly above the FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your 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.
294
Windshield Washer Fluid
What to Use
When you need windshield washer fluid, be sure
to read the manufacturer’s instructions before
use. If you will be operating your vehicle in an area
where the temperature may fall below freezing,
use a fluid that has sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the
washer symbol on it.
Add washer fluid
until the tank is full.
The windshield washer fluid reservoir is located in
the engine compartment on the driver’s side of
the vehicle.Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not mix water with ready-to-use washer
uid. Water can cause the solution to
freeze and damage your washer uid tank
and other parts of the washer system.
Also, water does not clean as well
as washer uid.
Fill your washer uid tank only
three-quarters full when it is very cold.
This allows for expansion if freezing
occurs, which could damage the tank if it
is completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
296
(28)= Inspect Electronic Vacuum Regulator
Valve (EVRV) filter for excessive contamination
or plugging. If needed, clean filter with solution
of soap and water, let dry and install.
(29)= Drain, flush, and refill cooling system.
This service can be complex; you should
have your dealer perform this service. See
Part C: Recommended Fluids and Lubricants
on page 397for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap, and
neck. Pressure test cooling system and pressure
cap. For Caterpillar
®diesel engines, always
refer to the Caterpillar®Diesel Engine Operation &
Maintenance Manual for coolant recommendations
and change intervals.
(30)= Change the lubricant. See
Part C: Recommended Fluids and
Lubricants on page 397.
(31)= Front axle service: Re-pack upper
kingpin roller bearing.(32)= Air brake service:
•Inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chafing,
etc. Inspect drum brake linings for wear or
cracks. Inspect other brake parts at each
wheel, including drums and wheel speed
sensor wiring. Check brake pedal for
excessive free play or travel (or every
6 months, whichever occurs first) and have
serviced if needed. Check brakes more often
if driving habits and conditions result in
frequent braking. Replace air dryer cartridge
only if excessive oil or moisture is present.
A small amount of oil in the system is normal
and should not be considered as a reason
to replace the cartridge.
•Test air lines for leaks; tighten as needed.
Replace compressor filter.
•Inspect air parking brake chamber for leaks
and damage. Inspect lines and hoses for
leaks, cracks, chafing, etc. Also check
all attachments for tightness, wear, or damage.
Note: The spring brake section of the rear
brake diaphragms are non-serviceable.
389
Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals
specified to help ensure the safety, dependability
and emission control performance of your
vehicle.
For your safety and that of others, any of the
safety-related components that may have been
damaged in an accident should be checked
and any needed repairs made before operating
the vehicle.
At the minimum, these routine checks should be
made every 6 months or 6,000 miles (10 000 km),
whichever occurs first. Whenever repairs are
needed, have them completed before operating
the vehicle.
At Each Fuel Fill
It is important for you or a service station attendant
to perform these underhood checks at each fuel ll.
Engine Oil Level Check
Check the engine oil level and add the proper
oil if necessary. SeeEngine Oil (Caterpillar®
Diesel Engine) on page 268orEngine Oil
(Gasoline Engine) on page 268orEngine Oil
(DURAMAX
®/Isuzu Diesel Engine) on page 272.
Engine Coolant Level Check
Check the engine coolant level and add
DEX-COOL®coolant mixture if necessary. See
Engine Coolant (Gas and DURAMAX®/Isuzu
Engines) on page 284orEngine Coolant
(Caterpillar
®Diesel Engines) on page 287.
Windshield Washer Fluid Level Check
Check the windshield washer fluid level in the
windshield washer fluid reservoir and add
the proper fluid if necessary. SeeWindshield
Washer Fluid on page 296.
Tire In ation Check
Check tire inflation cold. Make sure the tires are
inflated to the correct pressures. SeeLoading Your
Vehicle on page 238andIn ation - Tire Pressure
on page 322.
391
Part C: Recommended Fluids
and Lubricants
Fluids and lubricants identified below by name,
part number, or specification may be obtained
from your dealer.
Usage Fluid/Lubricant
Engine Oil
(Gasoline
Engine)Engine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certified for Gasoline Engines
starburst symbol. GM Goodwrench
®
oil meets all the requirements for
your vehicle. To determine the
proper viscosity for your vehicle’s
engine, see “Engine Oil” in the
Index.
Usage Fluid/Lubricant
Engine Oil
(DURAMAX
®/
Isuzu Diesel
Engines)Engine oil with the letters CJ-4
or CI-4 is best for your vehicle.
The CJ-4 or CI-4 designation
may appear either alone or in
combination with other API
designations, such as API CJ-4/SM.
These letters show American
Petroleum Institute levels of quality.
To determine the preferred viscosity
for your vehicle’s diesel engine,
see “Engine Oil” in the Index.
Engine Oil
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine
oil recommendations.
Engine Coolant
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine
coolant recommendations.
397
Usage Fluid/Lubricant
Engine Coolant
(Gasoline
Engine &
DURAMAX
®/
Isuzu Diesel)50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant (Gas
and DURAMAX®/Isuzu Engines)
on page 284orEngine Coolant
(Caterpillar
®Diesel Engines)
on page 287.
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid
or equivalent DOT-3 brake fluid.
Windshield
Washer SolventGM Optikleen
®Washer Solvent.
Clutch Bearing
LubricantClutch Bearing Lubricant
(GM Part No. 12378484 or
equivalent NLGI #3 consistency).
Exhaust Brake
Ball Joint Cap
LubricantHigh-Temperature Grease
(GM Part No. U.S. 1051344,
in Canada 903037) or
NLGI #3 consistency.
Usage Fluid/Lubricant
Power Steering
SystemDEXRON
®-VI Automatic
Transmission Fluid.
Manual
TransmissionSynthetic Manual Transmission
Fluid (GM Part No. U.S. 12345724,
in Canada 10953510).
Automatic
TransmissionSee the Allison Transmission
®
Operator’s Manual for correct
transmission fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241,
in Canada 10953474).
Chassis
LubricationChassis Lubricant
(GM Part No. U.S. 12377985,
in Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
398
Care of
Safety Belts............................................. 334
Your Cassette Tape Player....................... 202
Your CD Player........................................ 204
Your CDs ................................................. 203
Center Console Storage Area...................... 135
Center Passenger Position, Safety Belts........ 37
Charging System Light................................ 167
Check
Engine Light............................................ 174
Gages Warning Light............................... 180
Checking Things Under the Hood................ 266
Chemical Paint Spotting.............................. 338
Child Restraints
Child Restraint Systems............................. 49
Infants and Young Children........................ 45
Lower Anchors and Tethers for Children..... 57
Older Children........................................... 42
Securing a Child Restraint in a Rear
Outside Seat Position............................. 58
Securing a Child Restraint in the Center
Rear Seat Position (Crew Cab) or
Center Front Position.............................. 60
Securing a Child Restraint in the Right
Front Seat Position................................. 63
Where to Put the Restraint................. 54, 55
Chime Level Adjustment.............................. 204Cigarette Lighter.......................................... 157
Cleaning
Aluminum or Chrome-Plated Wheels........ 337
Exterior Lamps/Lenses............................. 335
Fabric/Carpet........................................... 333
Finish Care.............................................. 335
Inside of Your Vehicle .............................. 331
Instrument Panel, Vinyl, and Other
Plastic Surfaces.................................... 334
Tires........................................................ 337
Underbody Maintenance........................... 338
Washing Your Vehicle .............................. 335
Weatherstrips........................................... 334
Windshield and Wiper Blades................... 336
Climate Control System............................... 157
Outlet Adjustment..................................... 160
Rear Heating System............................... 161
Collision Damage Repair............................. 410
Control of a Vehicle..................................... 210
Coolant
Engine Temperature Gage........................ 173
Heater, Engine......................................... 111
Low Warning Light................................... 173
Surge Tank Pressure Cap........................ 288
Cooling System........................................... 290
Cruise Control............................................. 146
419