At Least Twice a Year
Wiper Blade Check
Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades, if
contaminated. Replace wiper blades that are worn or
damaged. SeeWindshield Wiper Blade Replacement on
page 5-76andWindshield and Wiper Blades on
page 5-98for more information.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. Part C tells you what to use.
Body Lubrication Service
Lubricate all exposed surfaces such as door checks,
door lock bolts, lock strike plates, door hinge bushings,
latches, and dovetail bumper wedges. Where oil holes
are provided, a dripless oil can be used. The seat
adjusters, seat track, door weatherstrips, and rubber cap
bumpers should also be lubricated. Part C tells you what
to use. More frequent lubrication may be required when
exposed to a corrosive environment.
Parking Brake Check
Park on a fairly steep hill and hold the vehicle with the
parking brake only. This checks holding ability. See
Parking Brake (With Hydraulic Brakes) on page 2-38or
Parking Brake (With Air Brakes) on page 2-41.
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brakes.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only
in PARK (P) or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service. On
manual transmission vehicles, the starter should
work only when the clutch pedal is all the way down.
6-27
Automatic Transmission Shift Indicator
Check
Check that the indicator points to the gear chosen.
Steering Check
Be alert for any changes in steering action, abnormal
front tire wear or steering wheel position. An inspection
or service is needed when the steering wheel is harder
to turn or has too much free play, or if there are strange
sounds when turning or parking.
Brake System Check
Be alert to the low air warning light or tone alarm, or
changes in braking action, such as repeated pulling to
one side, unusual sounds when braking or increased
brake pedal travel. Make sure air brake system
reservoirs are drained daily with full system air pressure,
and check system for leaks. Any of these conditions
could indicate the need for brake system inspection
and/or service.
Engine Cooling System Service
Inspect the hoses and have them replaced if they are
cracked, swollen, or deteriorated. Inspect all pipes,
fittings, and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of the
cooling system and pressure cap is recommended at
least once a year.
Exhaust System Inspection
Be alert for any changes in the sound of the exhaust
system or any smell of fumes. These are signs the
system may be leaking. Have it checked and/or repaired
at once. SeeEngine Exhaust on page 2-45and
Running the Vehicle While Parked on page 2-50.
Check to be sure that mud or dirt is not caked on the
exhaust system, especially in the area of the diesel
particulate filter and tailpipe. Clean the area as needed.
SeeDiesel Particulate Filter (Diesel Engine) on
page 2-46.
At high mileages, the DPF becomes loaded with ash.
This is normal. When the amount of ash loading is high,
see your dealer/retailer for DPF cleaning or replacement.
6-28
Part C: Recommended Fluids and
Lubricants
Fluids and lubricants identified below by name, part
number, or specification can be obtained from your
dealer/retailer.
Usage Fluid/Lubricant
Engine Oil
(Gasoline
Engine)Engine oil which meets
GM Standard GM6094M and
displays the American Petroleum
Institute (API) Certified for Gasoline
Engines starburst symbol. To
determine the proper viscosity for
your vehicle’s engine, see “Engine
Oil” in the Index.
Engine Oil
(DURAMAX
®/
Isuzu Diesel
Engines)Engine oils with the letters CJ-4 are
required for your vehicle. The CJ-4
designation can appear either alone
or in combination with other
American Petroleum Institute (API)
designations, such as API CJ-4/SL.
These letters show API 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.
Usage Fluid/Lubricant
Engine Coolant
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine
coolant recommendations.
Engine Coolant
(Gasoline
Engine &
DURAMAX
®/
Isuzu Diesel
Engines)50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant
(Caterpillar®Diesel Engines) on
page 5-44orEngine Coolant
(Gas and DURAMAX
®/Isuzu 7.8L
L6 Engines) on page 5-44.
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid or
equivalent DOT-3 brake fluid.
Windshield
Washer SolventOptikleen
®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.
Power Steering
SystemDEXRON
®-VI Automatic
Transmission Fluid.
Manual
TransmissionSynthetic Manual Transmission Fluid
(GM Part No. U.S. 88861952, in
Canada 88861953).
6-31
Usage Fluid/Lubricant
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.
Front Wheel
Bearings
(Except Oil
Filled Hubs)Wheel bearing lubricant meeting
requirements of NLGI #2,
Category GC or GC-LB
(GM Part No. U.S. 1051344, in
Canada 993037).
Front Wheel
Bearings with
Oil Filled HubsSAE 75W-90 Synthetic Axle
Lubricant for Medium Duty Trucks
(GM Part No. U.S. 89021675, in
Canada 10953512).
Transfer Case
(Four-Wheel
Drive)Manual Transmission Fluid
(GM Part No. U.S. 88861800, in
Canada 88861801).
Front Axle
(Four-Wheel
Drive)SAE 75W-90 Synthetic Axle
Lubricant for Medium Duty Trucks
(GM Part No. U.S. 89021675, in
Canada 10953512).
Usage Fluid/Lubricant
Rear Axle and
Rear HubsSAE 75W-90 Synthetic Axle
Lubricant for Medium Duty Trucks
(GM Part No. U.S. 89021675, in
Canada 10953512).
Rear Axle Shift
Motor LubricantRefrigerant Oil
(GM Part No. U.S. 5416939, in
Canada 10953496).
Propshafts and
SplinesWheel bearing lubricant meeting
requirements of NLGI #2, Category
GC or GC-LB
(GM Part No. U.S. 1051344, in
Canada 993037).
Cab — Door
Hinges and
LatchesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Weatherstrip
ConditioningWeatherstrip Lubricant
(GM Part No. U.S. 3634770, in
Canada 10953518) or
Dielectric Silicone Grease
(GM Part No. U.S. 12345579, in
Canada 992887).
Weatherstrip
SqueaksSynthetic Grease with
Teflon, Superlube
(GM Part No. U.S. 12371287, in
Canada 10953437).
6-32
Audio System(s).............................................3-48
Automatic Transmission
Fluid..........................................................5-43
Operation...................................................2-29
B
Battery..........................................................5-66
Bench Seat, Split............................................. 1-6
Brake
Diesel Engine Exhaust.................................2-26
Emergencies................................................ 4-5
Exhaust Indicator Light.................................3-40
Trailer Hand Control Valve.............................. 4-6
Brakes..........................................................5-57
Hydraulic Systems......................................... 4-4
Parking Brake Burnish Procedure...................2-43
System Warning Light..................................3-32
Braking........................................................... 4-4
Braking in Emergencies..................................... 4-5
Break-In, New Vehicle.....................................2-10
Bucket Seats................................................... 1-2
Bulb Replacement...........................................5-76
Buying New Tires...........................................5-85
C
California Perchlorate Materials Requirements....... 5-5
California Proposition 65 Warning....................... 5-5Capacities and Specifications..........................5-109
Carbon Monoxide...................................2-45, 4-16
Care of
Safety Belts................................................5-96
Center Console Storage Area...........................2-53
Change Fuel Filter Warning Light......................3-44
Charging System Light....................................3-30
Check
Engine Light...............................................3-36
Gages Warning Light...................................3-42
Checking Things Under the Hood......................5-22
Chemical Paint Spotting.................................5-100
Child Restraints
Child Restraint Systems...............................1-35
Infants and Young Children...........................1-31
Lower Anchors and Tethers for Children..........1-40
Older Children.............................................1-28
Securing a Child Restraint in a Rear Outside
Seat Position...........................................1-40
Securing a Child Restraint in the Center Front
Seat Position...........................................1-44
Securing a Child Restraint in the Center Rear
Seat Position...........................................1-42
Securing a Child Restraint in the Right Front
Seat Position...........................................1-44
Where to Put the Restraint...........................1-38
Chime Level Adjustment..................................3-58
Cigarette Lighter.............................................3-20
2
Specifications, Capacities...............................5-109
Speedometer..................................................3-26
Split Bench Seat.............................................. 1-6
Starting Diesel Engine.....................................2-14
Starting the Gasoline Engine............................2-12
Steering.......................................................... 4-9
Steering Wheel, Tilt Wheel................................. 3-7
Storage Areas................................................2-53
Center Console Storage Area........................2-53
Stuck in Sand, Mud, Ice, or Snow.....................4-19
Sun Visors...................................................... 2-9
Suspension, Air..............................................2-44
Switchbanks, Instrument Panel..........................3-18
T
Tachometer....................................................3-26
Theft-Deterrent, Radio.....................................3-57
Tilt Wheel........................................................ 3-7
Time, Setting..................................................3-48
Tires.............................................................5-82
Aluminum or Chrome-Plated Wheels,
Cleaning.................................................5-98
Buying New Tires........................................5-85
Cleaning....................................................5-99
Dual Tire Operation.....................................5-84
If a Tire Goes Flat.......................................5-92
Inflation - Tire Pressure................................5-82
Tightening the Wheel Nuts............................5-86Tires (cont.)
Wheel Alignment and Tire Balance.................5-86
Wheel Loading............................................5-83
Wheel Replacement.....................................5-90
When It Is Time for New Tires......................5-84
Tow Hooks.....................................................4-20
Towing
Your Vehicle...............................................4-24
Traction
Control System (TCS).................................... 4-8
Trailer
Connections................................................4-26
Trailer Brake Hand Control Valve........................ 4-6
Transmission
Fluid, Automatic...........................................5-43
Fluid, Manual..............................................5-43
Service Warning Light..................................3-31
Temperature Gage.......................................3-39
Transmission Operation, Automatic....................2-29
Transmission Operation, Manual........................2-30
Trip Odometer................................................3-26
Turn and Lane-Change Signals.......................... 3-8
Turn Signal/Multifunction Lever........................... 3-7
Two-Speed Rear Axle......................................2-27
U
Using this Manual................................................ ii
11