(30)= Change the lubricant. SeePart C: Recommended
Fluids and Lubricants on page 6-31.
(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.
•Replace the air compressor filter element, mounted
on the air compressor. For remote air compressor
intake service, refer to engine air cleaner filter
replacement.
•Remove, disassemble, clean, and inspect the safety
valve, service brake chambers, quick release valves,
quick release/double check valve combinations,
parking brake control valve, double check valves,
pressure protection valves, and ether injector
(if equipped).
•Remove, disassemble, and clean the application
valve; replace parts showing wear.
•Remove, disassemble, clean, and inspect the spring
brake control valve; replace rubber parts.
6-24
(33)= Clean and lubricate air brake automatic slack
adjuster. Check pushrod travel and auto adjustment
operation. Have serviced if needed.
(34)= Air brake chamber service: Check operation,
mounting clamps, and air lines and check for leaks.
(35)= Trailer brake hand control valve service: Check
operation; lubricate cam and follower.
(36)= Tighten the wheel stud nuts to the specified
torque values at 100 miles (160 km). Thereafter, tighten
them 1,000 miles (1 600 km) after each time the wheel
is removed. SeeTightening the Wheel Nuts on
page 5-86.
(37)= Inspect and clean any accumulated dirt, gravel,
or other foreign objects from the valves and valve boots
as needed. Using light oil, lubricate brake pedal to
brake application valve linkage components. Check any
rubber boots for cracks, holes, or deterioration and
replace if necessary.(38)= Estimated minimum. Actual mileage depends on
fuel and oil consumed.
(39)= If the vehicle has the Isuzu diesel engine and is
used primarily for long trip, highway service, change
the engine oil and filter every 18,000 miles (28 800 km),
or every 12 months, or every 750 hours of engine
operation, whichever occurs first.
(40)= Make sure any safety belt reminder light and
safety belt assemblies are working properly. Look
for any other loose or damaged safety belt system parts.
If you see anything that might keep a safety belt
system from doing its job, have it repaired. Have any
torn or frayed safety belts replaced.
6-25
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 to perform these underhood checks at
each fuel fill.
Engine Oil Level Check
Notice:It is important to check the engine oil
regularly and keep it at the proper level. Failure to
keep the engine oil at the proper level can cause
damage to the engine not covered by your warranty.Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil (Caterpillar
®Diesel Engine)
on page 5-23orEngine Oil (Gasoline Engine) on
page 5-24orEngine Oil (DURAMAX
®Diesel Engine) on
page 5-28orEngine Oil (Isuzu Diesel Engine) on
page 5-32.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
(Caterpillar®Diesel Engines) on page 5-44orEngine
Coolant (Gas and DURAMAX®/Isuzu 7.8L L6 Engines)
on page 5-44.
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 5-55.
Tire In ation Check
Check tire inflation cold. Make sure the tires are inflated
to the correct pressures. SeeLoading Your Vehicle
on page 4-21andInflation - Tire Pressure on page 5-82.
6-26
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
Underbody Inspection
Corrosive materials used for ice, snow removal, and
dust control can collect on the underbody. If these
materials are not removed, accelerated corrosion (rust)
can occur on underbody parts such as fuel lines, frame,
floor pan, and exhaust system. At least every spring,
flush these materials from the underbody with plain water.
Take care to clean well any areas where mud and other
debris can collect. Sediment packed in closed areas of
the frame should be loosened before being flushed.
Engine Cover Check
Check that the cab’s engine cover and seal, if the
vehicle has one, are not torn or damaged. Be sure that
the cover is clamped down firmly to the floor.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part C.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
Tractor Protection (Breakaway) Valve
Check
On air brake models, remove, disassemble, clean, and
inspect the tractor protection (breakaway) valve.
6-30
Service Publications Ordering
Information
Service Manuals
Service Manuals have the diagnosis and repair
information on engines, transmission, axle suspension,
brakes, electrical, steering, body, etc.
Service Bulletins
Service Bulletins’ give additional technical service
information needed to knowledgeably service
General Motors cars and trucks. Each bulletin contains
instructions to assist in the diagnosis and service of
your vehicle.
Owner Information
Owner publications are written specifically for owners
and intended to provide basic operational information
about the vehicle. The owner manual includes the
Maintenance Schedule for all models.
In-Portfolio: Includes a Portfolio, Owner Manual, and
Warranty Booklet.
RETAIL SELL PRICE: $35.00 (U.S.) plus processing fee
Without Portfolio: Owner Manual only.
RETAIL SELL PRICE: $25.00 (U.S.) plus processing fee
Current and Past Model Order Forms
Technical Service Bulletins and Manuals are available
for current and past model GM vehicles. To request
an order form, specify year and model name of
the vehicle.
ORDER TOLL FREE: 1-800-551-4123
Monday-Friday 8:00 AM - 6:00 PM
Eastern Time
For Credit Card Orders Only
(VISA-MasterCard-Discover), visit Helm, Inc. on the
World Wide Web at: www.helminc.com
Or you can write to:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207
Prices are subject to change without notice and without
incurring obligation. Allow ample time for delivery.
Note to Canadian Customers: All listed prices are
quoted in U.S. funds. Canadian residents are to make
checks payable in U.S. funds.
7-10
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