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(8)= This vehicle has the Engine 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 gasoline engine
vehicle more than 7,500 miles (12 000 km) or
12 months without an oil and filter change.
Remember to reset the Engine Oil Life System
whenever the oil is changed. For more information,
seeEngine Oil Life System (Gasoline Engine)
on page 276orEngine Oil Life System
(DURAMAX
®Diesel) on page 278orEngine
Oil Life System (Caterpillar®Diesel Engine)
on page 279.(9)= This vehicle has the Engine 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 15,000 miles (24 000 km) since
your last oil change. Under severe conditions,
the indicator may come on before 3,000 miles
(5 000 km). Never drive your 6.6L diesel engine
vehicle more than 15,000 miles (24 000 km),
or 12 months, or 750 engine hours, without an
oil and filter change.
Remember to reset the Engine Oil Life System
whenever the oil is changed. For more information,
seeEngine Oil Life System (Gasoline Engine)
on page 276orEngine Oil Life System
(DURAMAX®Diesel) on page 278orEngine
Oil Life System (Caterpillar®Diesel Engine)
on page 279.
(10)= Inspect rear axle air shift motor for fluid
leaks. Remove plug to check fluid level. Inspect
air lines and hoses for proper hook-up, binding,
leaks, etc. Inspect at 1,000 miles (1 600 km)
and 22,500 miles (36 000 km) and then every
22,500 miles (36 000 km) thereafter.
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(11)= Chassis Lubrication Service: Lubricate all
grease fittings in front suspension, front axle,
and steering linkage. DO NOT lubricate kingpin
bushings with air pressure equipment; instead,
use a hand grease gun to ensure complete purge
and eliminate sealer cap distortion. Front axle
tie rod ends, both upper and lower kingpin fittings,
and both steering linkage relay rod ends should
be greased with the vehicle loaded on the ground
and wheels turned straight ahead, NOT with
the vehicle on a hoist. Apply kingpin bushing
lubricant to both upper and lower kingpin grease
fittings until new lubricant purges from between
the upper shim pack and thrust bearing. Lubricate
transmission and shift linkage, hood latches
and hood hinges, parking brake lever pivot, clevis
pins and linkage, disc brake caliper rails, clutch
linkage and release bearing (if equipped), bearing
pads, propshaft universal joints, brake camshaft
bracket, slack adjusters, pedal shaft, clutch
cross shaft, clutch pedal springs, and clutch cable
bushing at transmission. Lubricate suspension,
axle, and steering linkage more often when
operating under dusty or muddy conditions and in
excessive off-road use. Frequently power-washed
vehicles will require more frequent lubrication.(12)= Check steering system:
•Look for damaged, loose, or missing parts.
Inspect the steering linkage relay rod and
tie rod ends for looseness or lack of lubricant.
Also look for parts showing signs of wear
or lack of lubrication. Replace parts as
needed. Also check steering gear mounting
bolts, pitman arm nut, gear housing upper
cover and side cover attaching bolts, steering
column mounting bolts and cardan joint
clamp bolts; tighten if necessary. See the
service manual.
•Inspect power steering hoses, tubes, and
fittings for leaks. Hoses and lines must not
be twisted, kinked, or tightly bent. Make sure
clips, clamps, supporting tubes, and hoses
are in place and properly secured.
•Check steering gear for leakage around
pitman shaft and housing. If leakage is evident
(lubricant oozing out, not just oily film), leak
should be corrected immediately.
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(13)= 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.
(14)= Adjust tire pressures as indicated on the
Certification or Tire Information label for optimum
tire life. SeeTires on page 321for 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.
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(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 397.
•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. See
Front Wheel Bearings with Oil-Filled Hubs
on page 319andPart C: Recommended
Fluids and Lubricants on page 397.
(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 415.
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(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. See
Part C: Recommended Fluids and Lubricants
on page 397for 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. See
Part C: Recommended Fluids and
Lubricants on page 397.
(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.
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•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.
(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 325.
(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.
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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 268orEngine Oil
(Gasoline Engine) on page 268orEngine Oil
(DURAMAX
®/Isuzu Diesel Engine) on page 272.
Engine Coolant Level Check
Check the engine coolant level and add
DEX-COOL®coolant mixture if necessary. See
Engine Coolant (Gas and DURAMAX®/Isuzu
Engines) on page 284orEngine Coolant
(Caterpillar
®Diesel Engines) on page 287.
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 296.
Tire In ation Check
Check tire inflation cold. Make sure the tires are
inflated to the correct pressures. SeeLoading Your
Vehicle on page 238andIn ation - Tire Pressure
on page 322.
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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
seeWindshield and Wiper Blades on page 336.
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.
392