Electric Air Compressor
The vehicle might have an electric air compressor.
This compressor is used to run options that require
pressurized air, such as an air horn or air seat.
The air compressor is used when vehicles do not have
an air brake system.
The air supply for this
system must be
maintained by releasing
the drain valve to eject any
moisture that could have
built up in the system.
It is recommended that this system be drained on a
weekly basis.
Clutch Pedal Free Travel
If the vehicle has a V8 engine and a manual
transmission, the clutch needs adjustment when pedal
free travel gets down to about 1/4 inch (6 mm), as
measured at the clutch pedal pad. There should be
1 1/2 to 2 inches (38 to 51 mm) of clutch pedal
free travel.
If the clutch ever needs service, be sure to use only
approved clutch replacement parts.
Chassis Lubrication
The Maintenance Schedule provides all of the required
chassis lubrication intervals and identifies proper
lubricants to use. Be sure to see the Maintenance
Schedule before performing any chassis lubrication
service. To determine location of chassis lubrication
items, use the following charts.
5-57
2. Push the release lever and slide the wiper assembly
toward the driver side of the vehicle.
3. Install a new blade by reversing Steps 1 and 2.
Other Service Items
Fuel Filter
Fuel Filter/Pressure Regulator
(Gasoline Engines)
The steel fuel filter/pressure regulator is located near
the engine compartment on the driver’s side frame rail.
If your vehicle has a rear steel fuel tank, the fuel
filter/pressure regulator is located near the rear fuel
tank, on the driver’s side frame rail. SeeScheduled
Maintenance on page 6-5for recommended service
intervals.
If your vehicle is equipped with the optional Davco
spin-on type filter, it is located on the driver’s side
frame rail.
Fuel Filter (Diesel Engines)
If you have a diesel engine, your fuel filter is located in
the engine compartment on the driver’s side of the
vehicle, or along the driver’s side frame rail. See “Fuel
Filter Replacement” earlier in this section for further
information.
Also seeScheduled Maintenance on page 6-5for
recommended service intervals.
5-72
Part A: Scheduled Maintenance
Services
In this part are scheduled maintenance services which
are to be performed at the mileage intervals specified.
Using the Maintenance Schedule
We want to help keep this vehicle in good working
condition. But we do not know exactly how you will drive
it. You might drive very short distances only a few
times a week. Or you might drive long distances all the
time in very hot, dusty weather. You might use the
vehicle in making deliveries or in many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You might need
more frequent checks and replacements. So please read
the following and note how you drive. If you have any
questions on how to keep the vehicle in good condition,
see your dealer/retailer.
This part tells you the maintenance services that should
be done and when to schedule them.
When you go to your dealer/retailer for service, trained
and supported service people will perform the work
using genuine parts.The proper fluids and lubricants to use are listed in
Part C. Make sure whoever services the vehicle uses
these. All parts should be replaced and all necessary
repairs done before you or anyone else drives the
vehicle.
This schedule is for vehicles that:
•carry passengers and cargo within recommended
limits on the vehicle’s Certification or Tire
Information label. SeeLoading the Vehicle on
page 4-20.
•are driven on reasonable road surfaces within legal
driving limits.
•use the recommended fuel. SeeGasoline Octane
on page 5-6for gasoline engine vehicles orWhat
Fuel to Use on page 5-8for diesel engine vehicles.
Scheduled Maintenance
Supplements
If the vehicle has a Caterpillar®diesel engine, the owner
manual is supplemented by the Caterpillar®Diesel
Engine Operation & Maintenance Manual. If the vehicle
has an Allison Transmission
®, the owner manual is
supplemented by an Allison Transmission®Operator’s
Manual. Always refer to these manuals for related
maintenance services.
6-4
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 and some DURAMAX
®diesel
and Isuzu diesel engine vehicles have a computer
that lets you know when to change the engine oil. This
is not based on mileage, but on engine operation
and engine temperature. When the computer has
calculated that the oil needs changing, the Engine Oil
Life System will indicate that a change is necessary. See
Engine Oil Life System (Gasoline Engine) on page 5-35
orEngine Oil Life System (DURAMAX/Isuzu Diesel
Engines) on page 5-36orEngine Oil Life System
(Caterpillar Diesel Engine) on page 5-38.
The “Footnotes” at the end of this Maintenance
Schedule further explain maintenance services.
SeeService Publications Ordering Information on
page 7-10.
100 Miles (160 km)
❑Wheel stud nut service.(36)
1,000 Miles (1 600 km)
❑Wheel stud nut service.(36)
❑Rear axle air shift motor service.(10)
7,500 Miles (12 000 km)
❑Gasoline Engine Only: Check engine oil life system.
If engine oil and filter are changed, reset system. See
“Engine Oil (Gasoline Engine)” in the Index.(2) (8)
❑Check fluid levels (or every 3 months, whichever
occurs first).(1) (5)
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Spring-to-axle U-bolts and shackle bolts service.(15)
❑Wheels and tires service.(14)
❑Hydraulic brake service (or every 6 months, whichever
occurs first).(6) (36)
❑Parking brake service (or every 6 months, whichever
occurs first).(21)
❑Air brake service (or every 6 months, whichever
occurs first).(32)
❑Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first).(33)
6-5
150,000 Miles (240 000 km)
❑Cooling system service (or every 60 months since
last service, whichever occurs first).(2) (29)
❑Diesel Engine Only: Inspect engine drive belt;
replace as necessary.
❑Isuzu Diesel Only: Diesel Particulate Filter (DPF)
service (or every 4,500 hours, whichever occurs
first). Then every 150,000 miles (240 000 km),
or every 4,500 hours, whichever occurs first.(7)
200,000 Miles (320 000 km)
❑Rear axle service — Eaton®, Rockwell®, Spicer®
axles (or every 12 months, whichever occurs
first).(30)
❑Remove, disassemble, clean, and inspect the air
brake trailer supply valve (or every 2 years, or
every 7,200 hours, whichever occurs first).
❑Diesel Engine Only: Inspect engine drive belt;
replace as necessary.
250,000 Miles (400 000 km)
❑Four-wheel drive only: Front axle service.(30)
❑Four-wheel drive only: Transfer case service.(30)
❑Manual transmission (except ZF 6-speed) fluid
replacement (or every 60 months, whichever occurs
first).
300,000 Miles (480 000 km)
❑Rear axle service — Eaton®, Rockwell®, Spicer®
axles (or every 12 months, whichever occurs
first).(30)
❑Remove, disassemble, clean, and inspect the air
brake air dryer (or every 3 years, or 10,800 hours,
whichever occurs first). Replace desiccant.
❑Isuzu Diesel Only: Diesel Particulate Filter (DPF)
service (or every 4,500 hours, whichever occurs
first). Then every 150,000 miles (240 000 km),
or every 4,500 hours, whichever occurs first.(7)
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 Transmission
®,
your owner manual is supplemented by an Allison
Transmission
®Operator’s Manual. Always refer to
these manuals for related maintenance services.
(2)= An Emission Control Service.
(3)= A Noise Emission Control Device.
6-20
(14)= Adjust tire pressures as indicated on the
Certification or Tire Information label for optimum tire
life. SeeTires on page 5-76for 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, including DPF
pressure lines, 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. 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 5-75andPart 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.
6-23
(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.(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.
6-24
Part B: Owner Checks and Services
These owner checks and services should be performed
at the intervals specified to help ensure vehicle
safety, dependability, and emission control performance.
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 the vehicle
warranty.Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil (DURAMAX Diesel Engine)
on page 5-24orEngine Oil (Caterpillar Diesel Engine)
on page 5-27orEngine Oil (Isuzu Diesel Engine) on
page 5-28orEngine Oil (Gasoline 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 5-47.
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 5-50.
Tire Inflation Check
Check tire inflation cold. Make sure the tires are inflated
to the correct pressures. SeeLoading the Vehicle on
page 4-20andInflation - Tire Pressure on page 5-77.
6-26