
(14)= Adjust tire pressures as indicated on the Gross
Vehicle Weight (GVW) Rating label for optimum tire life.
SeeTires on page 5-74for further details. Check
tires for excessive or abnormal wear or damage. Also
check for damaged wheels. Replace wheels and/or tires
as needed.
(15)= 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.
(16)= 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.
(17)= Check all gasoline engine drive belts for cracks,
fraying, and wear. Replace as needed.
(18)= Adjust valve lash. Incorrect valve clearance will
result in increased engine noise and reduced engine
output.(19)= 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.
(20)= Check shields and underhood insulation for
damage or looseness. Adjust or replace as needed.
(21)= Inspect parking brake drum and linings for wear
or cracks and check linkage and adjustment.
(22)= Wheel bearing service:
•Grease type — Clean, inspect, and lubricate with
the proper wheel bearing grease at designated
intervals or when hubs are removed. See
Part C: Recommended Fluids and Lubricants on
page 6-33.
•Oil-filled type — Some wheel bearings are
lubricated by axle lubricant. When you have oil-filled
hubs, use lubricant identical to that used in the
axle. Lubricant change intervals are the same for
front and rear axles. However, you must maintain
the proper oil level between change intervals.
SeeFront Wheel Bearings with Oil-Filled Hubs on
page 5-73andPart C: Recommended Fluids
and Lubricants on page 6-33.
6-25

(23)= Check the air intake system installation to see
that gaskets are seated properly and all hose
connections, fasteners, and other components are tight.
Tighten connections and fasteners or replace parts
as required.
(24)= Evaporative Control System Service, if
equipped: Check all fuel and vapor lines and hoses
for proper connections and correct routing (or every
24 months, whichever occurs first). Replace parts
as needed.
(25)= Replace spark plugs. Inspect wires for damage.
Check the wire boot and boot heat shield fit at spark
plugs and coil. Replace parts as needed.
(26)= Check the fuel tank, fuel cap and fuel lines for
damage which could cause leakage. Inspect fuel cap for
correct sealing ability and any indications of damage.
Check fuel cap gasket for even filler neck imprint.
Replace parts as needed.
(27)= Check Exhaust Gas Recirculation (EGR) system
as described in the service manual. SeeService
Publications Ordering Information on page 7-11.
(28)= Inspect Electronic Vacuum Regulator Valve
(EVRV) filter for excessive contamination or plugging.
If needed, clean filter with solution of soap and water, let
dry and install.(29)= Drain, flush, and refill cooling system. This
service can be complex; you should have your dealer
perform this service. SeePart C: Recommended Fluids
and Lubricants on page 6-33for what to use. Inspect
hoses. Clean radiator, condenser, pressure cap,
and neck. Pressure test cooling system and pressure
cap. For Caterpillar
®diesel engines, always refer to the
Caterpillar®Diesel Engine Operation & Maintenance
Manual for coolant recommendations and change
intervals.
(30)= Change the lubricant. SeePart C: Recommended
Fluids and Lubricants on page 6-33.
(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.
6-26

•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, standard brake chambers, quick release
valves, quick release/double check valve
combinations, parking brake control valve, double
check valves, pressure protection valves, and
alcohol 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.(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 5-77.
(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.
6-27

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 for you or a service station attendant to
perform these underhood checks at each fuel ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil (Caterpillar®Diesel Engine)
on page 5-24orEngine Oil (DURAMAX®Diesel) on
page 5-24orEngine Oil (Gasoline Engine) on page 5-28
for further details.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
(Gas and DURAMAX®Engines) on page 5-38orEngine
Coolant (Caterpillar®Diesel Engines) on page 5-40
for further details.
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 5-48
for further details.
6-28

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.
6-32

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. GM Goodwrench
®
oil meets all the requirements for
your vehicle. 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.
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
®
Diesel)50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant
(Gas and DURAMAX®Engines) on
page 5-38orEngine Coolant
(Caterpillar
®Diesel Engines) on
page 5-40.
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
®-VI Automatic
Transmission Fluid.
Manual
Transmission
(Except ZF
6-Speed)Synthetic Manual Transmission Fluid
(GM Part No. U.S. 12345724, in
Canada 10953510).
6-33

Engine
Air Cleaner/Filter.........................................5-35
Alarm and Automatic Shutdown.....................2-20
Battery.......................................................5-58
Change Engine Oil Light...............................3-40
Check and Service Engine Soon Light............3-38
Checks Before Operating..............................2-24
Coolant..............................................5-38, 5-40
Coolant Heater............................................2-26
Coolant Temperature Gage...........................3-36
Diesel Engine Exhaust Brake........................2-27
Exhaust.....................................................2-45
Exhaust Restrictor.......................................2-22
Fan Breakage............................................... 5-5
Fan Noise..................................................5-47
High Idle System.........................................2-21
Oil .....................................................5-24, 5-28
Oil Life System...........................5-31, 5-33, 5-34
Overheating................................................5-40
Overspeed Warning Light..............................3-40
Reduced Power Light...................................3-42
Shutdown Warning Light...............................3-40
Speed Limiter.............................................3-28
Starter Over-Crank Protection........................2-12
Starting Your Diesel.....................................2-15
Starting Your Gasoline..................................2-13Entry Lighting.................................................3-17
Event Data Recorders (EDR)............................. 7-6
Exhaust Brake Indicator Light...........................3-41
Exhaust Restrictor...........................................2-22
Extender, Safety Belt.......................................1-28
Exterior Lamps...............................................3-14
F
Filter
Engine Air Cleaner......................................5-35
Filter Minder Gage..........................................3-46
Finish Damage...............................................5-89
Fixed Mast Antenna........................................3-67
Flashers, Hazard Warning.................................. 3-6
Flat Tire........................................................5-82
Fluid
Automatic Transmission................................5-36
Manual Transmission....................................5-37
Power Steering...........................................5-47
Windshield Washer......................................5-48
Four-Wheel Drive....................................2-35, 5-65
Front Axle......................................................5-66
Front Wheel Bearings with Oil-Filled Hubs..........5-73
5

Fuel............................................................... 5-6
Additives...................................................... 5-6
Diesel Engine Fuel........................................ 5-7
Filling a Portable Fuel Container....................5-21
Filling Your Tank..........................................5-20
Filter..........................................................5-70
Filter Replacement.......................................5-18
Fuels in Foreign Countries............................5-19
Gage .........................................................3-45
Gasoline Octane........................................... 5-6
Gasoline Specifications.................................. 5-6
Primary Filter and Water Separator................5-71
Running Out of Fuel....................................5-17
Secondary Filter and Water Separator/Heater....5-71
Very Cold Weather Operation........................5-10
Water in Fuel..............................................5-10
Water in Warning Light.................................3-46
What Fuel to Use.......................................... 5-8
Fuses
Fuses and Circuit Breakers...........................5-93
Instrument Panel Fuse Block.........................5-94
Underhood Fuse Block.................................5-96
Windshield Wiper.........................................5-93G
Gage
Air Pressure...............................................3-47
Check Gages Warning Light..........................3-44
Engine Coolant Temperature.........................3-36
Filter Minder...............................................3-46
Fuel..........................................................3-45
Hourmeter..................................................3-47
Oil Pressure...............................................3-38
Speedometer..............................................3-27
Tachometer.................................................3-27
Transmission Temperature.............................3-41
Voltmeter Gage...........................................3-32
Gasoline
Octane........................................................ 5-6
Specifications............................................... 5-6
Gasoline Engine, Starting.................................2-13
GM Mobility Reimbursement Program.................. 7-5
6