At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light (if equipped)
and all your belts, buckles, latch plates, retractors
and anchorages 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.
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
Cleaning the Outside of Your Vehicle on page 5-80.
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.
6-25
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. See “Parking Brake” if necessary.
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), if equipped, or NEUTRAL (N). If
the starter works in any other position, your vehicle
needs service.
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 illumination of the low air warning lamp or for
the 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.
6-26
Exhaust System Check
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. Refer toEngine Exhaust on page 2-37and
Running Your Engine While You Are Parked on
page 2-38.
Windshield Wipers and Washers Check
Check operation and condition of the wiper blades.
Check the flow of the washer spray.
Defroster Check
Move the control to the defrost symbol and the fan to HI
or the high symbol. Then check the airflow from the
ducts at the inside base of the windshield.
Mirrors and Sun Visors Check
Check that friction joints hold mirrors and sun visors in
place.
Seat Adjuster Check
When adjusting a manual seat, be sure seat adjusters
latch by attempting to move the seat after latching.
Lamps Check
Check panel lighting, warning lights, indicator lights and
interior lamps. On the outside, check: license plate
lamps, sidemarker lamps, reflectors or lights on outside
mirrors, headlamps, parking lamps, identification and
clearance lamps, taillamps, brake lamps, turn signals,
backup lamps and hazard warning flashers. Have
headlamp aim checked at once if beams seem
improperly aimed.
Glass, Mirrors, Lamps and/or
Re ectors Condition Check
Look for broken, scratched, dirty or damaged glass,
mirrors, lamps or reflectors that could reduce the view
or visibility or cause injury. Replace, clean or repair
promptly.
Door Latches Check
Check that doors close, latch and lock tightly. Check for
broken, damaged or missing parts that might prevent
tight latching.
6-27
Hood Latches Check
Check that the hood closes firmly. Check for broken,
damaged, loose or missing parts that might prevent tight
latching. Make sure the secondary latch (if equipped)
keeps the hood from opening all the way when the
primary latch is released.
Fluid Leaks Check
Check for fuel, coolant, oil or other fluid leaks by looking
at the surface beneath the vehicle after it has been
parked for awhile.
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 equipped)
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.
6-28
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. To determine the
proper viscosity for your vehicle’s
engine, see “Engine Oil” in the
Index.
Engine Oil
(DURAMAX™
Diesel Engine)Engine oil with the letters CI-4 or
CH-4 is best for your vehicle. The
CI-4 or CH-4 designation may
appear either alone or in
combination with other API
designations, such as API CI-4/SL.
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.
Usage Fluid/Lubricant
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.
Engine Coolant
(Gasoline
Engine &
DURAMAX™
Diesel)50/50 mixture of clean, drinkable
water and use only
DEX-COOL
®Coolant. See “Engine
Coolant” in the Index.
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.
Power Steering
SystemDEXRON
®-III Automatic
Transmission Fluid.
6-29
Just dial GM Medium Duty Truck Roadside Assistance
at 1-800-862-4389 to reach a qualified representative
who can assist you in a repair or arrange a tow. We also
provide dealer information at no charge, such as
location of the nearest authorized medium duty
GM Truck dealer and their hours of operation.
Roadside Assistance is available 24 hours a day,
7 days a week, 365 days a year, including weekends
and holidays. Should you have any questions about
Roadside Assistance, call the GM Medium Duty Truck
Roadside Assistance Center or contact your dealer.
Vehicle Data Collection and
Event Data Records
Your vehicle, like other modern motor vehicles, has a
number of sophisticated computer systems that monitor
and control several aspects of the vehicle’s
performance. Your vehicle uses on-board vehicle
computers to monitor emission control components to
optimize fuel economy, to monitor conditions for air bag
deployment and, if so equipped, to provide anti-lock
braking and to help the driver control the vehicle
in difficult driving situations. Some information may be
stored during regular operations to facilitate repair
of detected malfunctions; other information is stored only
in a crash or near crash event by computer systems
commonly called event data recorders (EDR).In a crash or near crash event, computer systems, such
as the Air Bag Sensing and Diagnostic Module (SDM)
in your vehicle may record information about the
condition of the vehicle and how it was operated, such
as engine speed, brake applications, throttle position,
vehicle speed, safety belt usage, air bag readiness, air
bag performance data, and the severity of a collision.
This information has been used to improve vehicle crash
performance and may be used to improve crash
performance of future vehicles and driving safety. Unlike
the data recorders on many airplanes, these on-board
systems do not record sounds, such as conversation of
vehicle occupants.
To read this information, special equipment is needed
and access to the vehicle or the SDM is required.
GM will not access information about a crash event or
share it with others other than
•with the consent of the vehicle owner or, if the
vehicle is leased, with the consent of the lessee,
•in response to an official request of police or similar
government office,
•as part of GM’s defense of litigation through the
discovery process, or
•as required by law.
7-5
Reporting Safety Defects to the
Canadian Government
If you live in Canada, and you believe that your vehicle
has a safety defect, you should immediately notify
Transport Canada, in addition to notifying General
Motors of Canada Limited. You may write to:
Transport Canada
330 Sparks Street
Tower C
Ottawa, Ontario K1A 0N5
Reporting Safety Defects to
General Motors
In addition to notifying NHTSA (or Transport Canada) in
a situation like this, we certainly hope you’ll notify us.
Please call us at 1-800-862-4389, or write:
GM Medium Duty Truck
Customer Assistance Center
P.O. Box 44947
Detroit, MI 48244In Canada, please call us at 1-800-263-3777 (English)
or 1-800-263-7854 (French). Or, write
General Motors of Canada Limited
Customer Communication Centre, 163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Service Publications Ordering
Information
Service Manuals
Service Manuals have the diagnosis and repair
information on engines, transmission, axle, suspension,
brakes, electrical, steering, body, etc.
RETAIL SELL PRICE: $120.00
7-7
A
Accessory Power Outlets.................................3-17
Adding Equipment to Your Air Bag-Equipped
Vehicle.......................................................1-61
Adding Washer Fluid.......................................5-44
Additives, Fuel................................................. 5-7
Add-On Electrical Equipment............................5-86
Adjusting the Speakers
(Balance/Fade)............................3-47, 3-50, 3-54
Air Bag
Off Light.....................................................3-28
Readiness Light..........................................3-27
Air Bag System..............................................1-48
Adding Equipment to Your Air Bag-Equipped
Vehicle...................................................1-61
Air Bag Off Switch.......................................1-55
How Does an Air Bag Restrain?....................1-53
Servicing Your Air Bag-Equipped Vehicle.........1-60
What Makes an Air Bag Inflate?....................1-53
What Will You See After an Air Bag Inflates? . . 1-54
When Should an Air Bag Inflate?...................1-53
Where Are the Air Bags?..............................1-52
Air Brake.......................................................2-35
Air Brake System Warning Light........................3-33
Air Brake Systems..........................................5-50
Air Cleaner/Filter, Engine.................................5-30
Air Conditioning System...................................5-67Air Connections..............................................4-36
Air Dryer.......................................................5-50
Air Pressure Gage..........................................3-44
Air Shift Control (Automatic Transmission)..........2-27
Air Suspension...............................................2-27
Air Suspension Seats........................................ 1-6
Airbag Sensing and Diagnostic Module (SDM)...... 7-5
All Overseas Locations...................................... 7-4
Allison Transmission
®External Filters...............5-100
Aluminum or Chrome-Plated Wheels..................5-82
AM ...............................................................3-57
AM-FM Radio.................................................3-46
Antenna, Fixed Mast.......................................3-59
Anti-lock Brake System (ABS)............................ 4-7
Anti-Lock Brake, System Warning Light..............3-34
Anti-Lock Brakes, Trailer System
Warning Light.............................................3-35
Appearance Care............................................5-76
Care of Safety Belts....................................5-79
Chemical Paint Spotting...............................5-83
Cleaning the Inside of Your Vehicle................5-77
Cleaning the Outside of Your Vehicle..............5-80
Finish Damage............................................5-83
Sheet Metal Damage...................................5-82
Underbody Maintenance...............................5-83
Vehicle Care/Appearance Materials................5-84
Weatherstrips..............................................5-79
Ashtrays........................................................3-18
1