Air Filter Restriction Indicator
If your vehicle has this
feature, the gage is
located above the
switchbank in the center of
the instrument panel. It
monitors the engine
air filter.
As the filter gets dirty, the yellow indicator will begin to
rise. When it reaches 25 inches of vacuum on the
scale, the filter should be replaced.
After replacing the filter, reset the gage by pressing in
the yellow reset button at the bottom of the gage.
If you have a Caterpillar
®diesel engine, also see your
Caterpillar®Operation & Maintenance Manual.
Air Pressure Gage
If your vehicle has air
brakes, the air pressure
gage is located above the
switchbank in the center
of the instrument panel.
This gage shows the air pressure for both your front
and rear brake systems.
If the needle on the gage indicates that the air pressure
is below 60 to 75 psi (415 to 517 kPa), the low air
warning light will come on. An alarm will also sound if
this happens.
The yellow pointer shows the pressure available for the
front system, while the green pointer shows pressure
for the rear. There should be no more than 4 psi
(28 kPa) difference showing between the systems.
Don’t drive until both pointers are showing at least
115 psi (793 kPa), so you’ll have enough air if you need
to apply your brakes.
3-44
Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown after 100,000 miles
(166 000 km) should be repeated at the same miles (km)
after those intervals for the life of this vehicle.
Gasoline engine vehicles have a computer that lets you
know when to change your engine oil. This is not
based on mileage, but on engine revolutions and engine
operating temperature. When the computer has
calculated that the oil needs changing, the GM Oil Life
System will indicate that a change is necessary.
The “Footnotes” at the end of this Maintenance
Schedule further explain maintenance services.
SeeService Publications Ordering Information on
page 7-7.
100 Miles (160 km)
❑Wheel stud nut service.(46)
1,000 Miles (1 600 km)
❑Wheel stud nut service.(46)
❑Rear axle air shift motor service.(11)
7,500 Miles (12 000 km)
❑Gasoline Engine Only: Check Oil Life System. If
engine oil and filter are changed, reset system. See
“Engine Oil (Gasoline Engine)” in the Index.(3) (9)
❑Check fluid levels (or every 3 months, whichever
occurs first).(1) (6)
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(12)
❑Wheels and tires service.(15)
❑Hydraulic brake service (or every 6 months, whichever
occurs first).(7) (46)
❑Parking brake service (or every 6 months, whichever
occurs first).(8)
❑Air brake service (or every 6 months, whichever
occurs first).(39)
❑Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first).(40)
❑Check air brake relay valve operation and check for
leaks (or every month, or every 300 hours, whichever
occurs first).
❑Clean air brake application valve (or every 3 months,
or every 300 hours, whichever occurs first). Lubricate
linkage.
❑Air brake chamber service (or every 2 months,
whichever occurs first).(41)
❑Trailer brake hand control valve service (or every
3 months, or every 900 hours, whichever occurs
first).(42)
6-5
300,000 Miles (480 000 km)
❑Remove, disassemble, clean and inspect the air
brake air dryer (or every 3 years, or 10,800 hours,
whichever occurs first). Replace desiccant on
Bendix-Westinghouse units.
Footnotes
† = The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
(1)= If your vehicle has an Allison automatic
transmission, your GM owner’s manual is supplemented
by an Allison Transmission
®Operator’s Manual.
Always refer to these manuals for related maintenance
services.
(2)= Refer to the Caterpillar
®Diesel Engine Operation
and Maintenance Manual for oil recommendations
and change intervals.
(3)= An Emission Control Service.
(4)= A Noise Emission Control Device.
(5)= Applies only to vehicles sold in the United States.(6)= Check fluid level in brake master cylinder, power
steering pump, axle, transmission and hydraulic
spring parking brake pump (if equipped). A low fluid
level in the brake master cylinder can indicate
worn brake linings and should be checked accordingly.
(7)= Inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chafing, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect caliper assemblies. 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.
(8)= Inspect parking brake drum and linings for wear or
cracks and check linkage and adjustment.
(9)= This vehicle has the GM Oil Life System. This
system will show you when to change the engine oil and
filter – usually between 3,000 miles (5 000 km) and
7,500 miles (12 000 km) since your last oil change.
Under severe conditions, the indicator may come on
before 3,000 miles (5 000 km). Never drive your vehicle
more than 7,500 miles (12 000 km) or 12 months
without an oil and filter change.
Remember to reset the Oil Life System whenever the oil
is changed. For more information, seeChange Engine
Oil Light on page 3-39.
6-19
Safety Belts (cont.)
Safety Belt Extender....................................1-26
Safety Belt Use During Pregnancy.................1-21
Safety Belts Are for Everyone......................... 1-8
Safety Warnings and Symbols.............................. iii
Scheduled Maintenance..................................... 6-5
Scheduled Maintenance Supplements.................. 6-4
Seat Adjuster Check........................................6-27
Seatback Adjustment......................................... 1-3
Seats
Air Suspension Seats.................................... 1-6
Manual........................................................ 1-2
Rear Seat Operation...................................... 1-7
Reclining Seatbacks...................................... 1-4
Split Bench Seat........................................... 1-6
Securing a Child Restraint
Center Rear Seat Position (Crew Cab) or
Center Front Position................................1-41
Rear Outside Seat Position...........................1-39
Right Front Seat Position..............................1-43
Service........................................................... 5-3
Doing Your Own Work................................... 5-4
Engine Soon Light.......................................3-37
Publications Ordering Information..................... 7-7
Transmission Warning Light..........................3-31
Two Safety Cautions about Engine Fan
Breakage.................................................. 5-5Service Bulletins............................................... 7-8
Service Engine Soon Light...............................3-37
Service Manuals............................................... 7-7
Servicing Your Air Bag-Equipped Vehicle............1-60
Setting Preset Stations....................3-47, 3-49, 3-54
Setting the Time.............................................3-45
Setting the Tone (Bass/Treble)..........3-47, 3-49, 3-54
Sheet Metal Damage.......................................5-82
Shoulder Belt Height Adjuster...........................1-15
Skidding........................................................4-16
Sliding Rear Windows.....................................2-10
Some Other Rainy Weather Tips.......................4-20
Special Fabric Cleaning Problems.....................5-78
Specifications, Capacities.................................5-93
Speedometer..................................................3-25
Split Bench Seat.............................................. 1-6
Starter Motor Operation...................................2-13
Starter Switch Check.......................................6-26
Starting Your Diesel Engine..............................2-14
Starting Your DURAMAX™ Diesel Engine...........2-19
Starting Your Engine...............................2-13, 2-19
Starting Your Gasoline Engine..........................2-12
Steering........................................................4-12
Steering Check...............................................6-26
Steering in Emergencies..................................4-13
Steering Tips..................................................4-12
Stopping the Diesel Engine..............................2-15
Stopping the Gasoline Engine...........................2-14
13