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
(14)= Check front and rear suspension. Look for
damaged, loose or missing parts or parts showing signs
of wear or lack of lubrication. Replace parts as
needed.
(15)= Adjust tire pressures as indicated on the GVW
Rating label for optimum tire life. SeeTires on page 5-68
for further details. Check tires for excessive or
abnormal wear or damage. Also check for damaged
wheels. Replace wheels and/or tires as needed.
(16)= Check spring-to-axle U-bolts and shackle bolts
for proper torque. See the service manual for torque
sequence and specifications. When parts are replaced,
the torque must be checked and adjusted more often
during the first 6,000 miles (10 000 km). Check torque at
500 miles (800 km) and 2,000 miles (3 000 km) after
first use of parts.
(17)= Check complete exhaust system and cab areas
near the exhaust system for broken, damaged,
missing or out-of-position parts. Also inspect for open
seams, holes, loose connections or other conditions
which could let exhaust fumes seep into the driver
compartment. Needed repairs should be made at once.
To help maintain system integrity, replace exhaust
pipes whenever a new muffler is put on.(18)= Check all gasoline engine drive belts for cracks,
fraying and wear. Replace as needed.
(20)= With the engine off and below normal operating
temperature, check to see that the thermostatically
controlled engine cooling fan can be rotated by hand on
viscous-operated drives. Replace as needed.
(21)= Check shields and underhood insulation for
damage or looseness. Adjust or replace as needed.
23)= Wheel bearing service:
•Grease type – Clean, inspect and lubricate with the
proper wheel bearing grease at designated intervals
or when hubs are removed. SeePart C:
Recommended Fluids and Lubricants on page 6-29.
•Oil-filled type – Some wheel bearings are lubricated
by rear axle lubricant. When you have oil-filled
hubs, use lubricant identical to that used in your rear
axle. Lubricant change intervals are the same for
front and rear axles. However, you must maintain oil
level at the OIL LEVEL mark between change
intervals. SeePart C: Recommended Fluids and
Lubricants on page 6-29.
6-21
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
Driving on Snow or Ice....................................4-26
Driving Through Deep Standing Water...............4-20
Driving Through Flowing Water.........................4-20
Dual Tire Operation.........................................5-69
E
Eaton®Fuller®Five and Six-Speed
Transmissions and TTC Spicer Seven-Speed
Transmissions.............................................2-30
Eaton
®Fuller®Nine and Ten-Speed
Non-Synchronized Manual Transmissions........2-32
Electric Air Compressor...................................5-51
Electrical Connections......................................4-36
Electrical System
Add-On Equipment......................................5-86
Fuses and Circuit Breakers...........................5-87
Fusible Links..............................................5-87
Headlamp Wiring.........................................5-86
Power Windows and Other Power Options......5-87
Windshield Wiper Fuses...............................5-87
Elevated Idle/Exhaust Restrictor........................2-21
Engine
Air Cleaner/Filter.........................................5-30
Battery.......................................................5-55
Change Engine Oil Light...............................3-39
Check and Service Engine Soon Light............3-37Engine (cont.)
Checks Before Operating..............................2-22
Coolant..............................................5-32, 5-35
Coolant Heater............................................2-23
Coolant Temperature Gage...........................3-35
Diesel Engine Exhaust Brake........................2-25
Drive Belt Routing......................................5-103
Exhaust.....................................................2-37
Fan Noise..................................................5-43
Oil .....................................................5-20, 5-25
Overheating................................................5-36
Overspeed Warning Light..............................3-39
Reduced Power Light...................................3-41
Shutdown Warning Light...............................3-39
Starting Your Diesel.....................................2-14
Starting Your DURAMAX™ Diesel..................2-19
Starting Your Gasoline..................................2-12
Engine Alarm and Automatic Shutdown..............2-16
Engine Coolant Level Check.............................6-24
Engine Cooling System Service........................6-26
Engine Cover Check.......................................6-28
Engine Oil Additives................................5-23, 5-29
Engine Oil Level Check...................................6-24
Engine Road Speed Governor..........................3-25
Engine Speed Limiting.....................................3-25
Engine Starter Over-Crank Protection.................2-12
Event Data Records (EDR)................................ 7-5
Exhaust Brake Indicator Light...........................3-40
5
G
Gage
Air Pressure...............................................3-44
Check Gages Warning Light..........................3-42
Engine Coolant Temperature.........................3-35
Filter Minder...............................................3-44
Fuel..........................................................3-42
Hourmeter..................................................3-45
Oil Pressure...............................................3-37
Speedometer..............................................3-25
Tachometer.................................................3-26
Transmission Temperature.............................3-40
Voltmeter Gage...........................................3-30
Gasoline
Octane........................................................ 5-6
Specifications............................................... 5-6
Gasoline Engine, Starting.................................2-12
Gasoline Engine Warm-Up...............................2-14
Glass, Mirrors, Lamps and/or Reflectors
Condition Check..........................................6-27
H
Hazard Warning Flashers................................... 3-5
Headlamp High/Low-Beam Changer.................... 3-8
Headlamp Wiring............................................5-86Headlamps On Reminder.................................3-13
Heavy-Duty Trailer Wiring Package....................4-35
Height Adjustment............................................. 1-6
High Idle System (Caterpillar
®Diesel and
Gasoline Engines).......................................2-16
Highway Hypnosis...........................................4-23
Hill and Mountain Roads..................................4-23
Hood
Checking Things Under................................5-18
Latches......................................................5-19
Hood Latches Check.......................................6-28
Horn............................................................... 3-6
Hourmeter Gage.............................................3-45
How to Add Coolant to the Coolant
Surge Tank.................................................5-39
How to Add Fluid............................................5-32
How to Check................................................5-69
How to Check and What to Use...............5-31, 5-32
How to Check Fluid........................................5-61
How to Check Lubricant...................................5-61
How To Check Power Steering Fluid..................5-43
How to Inspect the Engine Air Cleaner/Filter.......5-30
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-13
Hydraulic Brake System
Warning Lights............................................3-32
Hydraulic Brake Systems................................... 4-6
Hydraulic Brakes.............................................2-33
Hydroplaning..................................................4-20
7