(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. SeePart C:
Recommended Fluids and Lubricants on page 6-31.
•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 5-81andPart C: Recommended Fluids
and Lubricants on page 6-31.
(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 7-10.
(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/retailer perform this service. SeePart C:
Recommended Fluids and Lubricants on page 6-31for
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.
6-23
(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
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.
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 the
vehicle has one, 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.
6-29
Dome Lamps.................................................3-16
Door
Locks.......................................................... 2-6
Power Door Locks......................................... 2-7
Driving
At Night.....................................................4-13
Defensive..................................................... 4-2
Drunken....................................................... 4-3
Highway Hypnosis.......................................4-15
Hill and Mountain Roads..............................4-15
In Rain and on Wet Roads...........................4-14
Rocking Your Vehicle to Get it Out.................4-20
Tow Hooks.................................................4-20
Winter........................................................4-16
Dual Tire Operation.........................................5-84
E
EDR .............................................................7-11
Electrical System
Add-On Equipment.....................................5-102
Fuses and Circuit Breakers.........................5-103
Fusible Links.............................................5-103
Headlamp Wiring.......................................5-102
Instrument Panel Fuse Block.......................5-103
Power Windows and Other Power Options....5-103
Underhood Fuse Block...............................5-106
Windshield Wiper Fuses.............................5-102Engine
Air Cleaner/Filter.........................................5-39
Alarm and Automatic Shutdown.....................2-18
Change Engine Oil Light...............................3-38
Check and Service Engine Soon Light............3-36
Checks Before Operating..............................2-23
Coolant......................................................5-44
Coolant Heater............................................2-25
Coolant Temperature Gage...........................3-35
Diesel Engine Exhaust Brake........................2-26
Drive Belt Routing......................................5-117
Exhaust.....................................................2-45
Exhaust Restrictor.......................................2-22
Fan Breakage............................................... 5-6
Fan Noise..................................................5-54
High Idle System.........................................2-20
Oil ....................................5-23, 5-24, 5-28, 5-32
Oil Life System...........................5-36, 5-37, 5-39
Overheating................................................5-48
Reduced Power Light...................................3-41
Shutdown Warning Light...............................3-39
Speed Limiter.............................................3-27
Starter Over-Crank Protection........................2-12
Starting Diesel............................................2-14
Starting the Gasoline...................................2-12
Engine Overspeed Warning Light......................3-39
Entry Lighting.................................................3-17
Event Data Recorders.....................................7-11
4
Exhaust Brake Indicator Light...........................3-40
Exhaust Restrictor...........................................2-22
Extender, Safety Belt.......................................1-28
Exterior Lamps...............................................3-14
F
Filter
Engine Air Cleaner......................................5-39
Filter Minder Gage..........................................3-45
Finish Damage...............................................5-99
Fixed Mast Antenna........................................3-58
Flashers, Hazard Warning.................................. 3-6
Flat Tire........................................................5-92
Fluid.............................................................5-43
Power Steering...........................................5-54
Windshield Washer......................................5-55
Four-Wheel Drive....................................2-32, 5-73
Front Axle......................................................5-74
Front Wheel Bearings with Oil-Filled Hubs..........5-81
Fuel............................................................... 5-7
Additives...................................................... 5-8
Change Filter Warning Light..........................3-44
Diesel Engine Fuel........................................ 5-9
Filling a Portable Fuel Container....................5-21
Filling the Tank...........................................5-20
Filter..........................................................5-78
Filter Replacement.......................................5-18
Fuels in Foreign Countries............................5-19Fuel (cont.)
Gage.........................................................3-43
Gasoline Octane........................................... 5-7
Gasoline Specifications.................................. 5-7
Primary Filter and Water Separator................5-79
Running Out of...........................................2-50
Running Out of Fuel....................................5-17
Secondary Filter and Water Separator/
Heater....................................................5-80
Very Cold Weather Operation........................5-12
Water in Fuel..............................................5-12
Water in Warning Light.................................3-44
What Fuel to Use.......................................... 5-9
Fuses
Fuses and Circuit Breakers.........................5-103
Instrument Panel Fuse Block.......................5-103
Underhood Fuse Block...............................5-106
Windshield Wiper.......................................5-102
G
Gage
Air Pressure...............................................3-46
Check Gages Warning Light..........................3-42
Engine Coolant Temperature.........................3-35
Filter Minder...............................................3-45
Fuel..........................................................3-43
Hourmeter..................................................3-46
Oil Pressure...............................................3-37
5