Instrument Panel, Vinyl, and Other
Plastic Surfaces
A soft cloth dampened with water may be used to
remove dust. If a more thorough cleaning is necessary,
a clean soft cloth dampened with a mild soap solution
can be used to gently remove dust and dirt. Never use
spot lifters or removers on plastic surfaces. Many
commercial cleaners and coatings that are sold to
preserve and protect soft plastic surfaces may
permanently change the appearance and feel of your
interior and are not recommended. Do not use silicone or
wax-based products, or those containing organic solvents
to clean your vehicle’s interior because they can alter the
appearance by increasing the gloss in a non-uniform
manner.
Some commercial products may increase gloss on your
instrument panel. The increase in gloss may cause
annoying reflections in the windshield and even make it
difficult to see through the windshield under certain
conditions.
Care of Safety Belts
Keep belts clean and dry.
{CAUTION:
Do not bleach or dye safety belts. If you do, it
may severely weaken them. In a crash, they
might not be able to provide adequate
protection. Clean safety belts only with mild
soap and lukewarm water.
Weatherstrips
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 frequent application may be required. See
Part C: Recommended Fluids and Lubricants on
page 6-31.
5-96
Engine Drive Belt Routing
Air conditioning compressor (A)
Dual Generators (B)Air conditioning compressor (A)
Air brake compressor (B) 8.1L V8 Engine (C4, C5)
8.1L V8 Engine (C6,C7,C8)
5-117
❑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)
❑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).(34)
❑Air compressor dry element pleated paper air strainer
service (or every 2 months, or every 800 hours,
whichever occurs first).
❑C600, C700, and C800 Gasoline Engines Only:
Engine drive belts service (or every 12 months,
whichever occurs first.)(17)
❑Thermostatically controlled engine cooling fan
service.(3) (19)
❑Shields and underhood insulation service.(3) (4) (20)
❑Gasoline Engine: Air compressor remote mounted
air filter dry element pleated paper air strainer
service (or every 6 months or every 1800 hours,
whichever occurs first).37,500 Miles (60 000 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)
❑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)
❑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).(34)
6-9
❑Exhaust system service (or every 6 months,
whichever occurs first).(2) (3) (16)
❑Wheel bearing (grease type) service (and whenever
hubs are removed).(22) (36)
❑Wheels and tires service.(14)
❑Isuzu Diesel Engine Only: Adjust valve lash (or every
2,625 hours of engine operation, whichever
occurs first).(18)
❑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)
❑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).(34)
❑Air compressor dry element pleated paper air strainer
service (or every 2 months, or every 800 hours,
whichever occurs first).❑C600, C700, and C800 Gasoline Engines Only:
Engine drive belts service (or every 12 months,
whichever occurs first).(17)
❑Thermostatically controlled engine cooling fan
service.(3) (19)
❑Shields and underhood insulation service.(3) (4) (20)
❑Gasoline Engine: Air compressor remote mounted
air filter dry element pleated paper air strainer
service (or every 6 months or every 1800 hours,
whichever occurs first).
67,500 Miles (108 000 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)
❑Cooling system service. Clean the cooling system
filler cap with clean water, clean the core, pressure
test the cap and the system for proper pressure
capability, and inspect condition of cooling and heater
hoses and clamps. Replace hoses if cracked,
swollen, or damaged.
❑Wheels and tires service.(14)
6-13
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Cooling system service. Clean the cooling system
filler cap with clean water, clean the core, pressure
test the cap and the system for proper pressure
capability, and inspect condition of cooling and heater
hoses and clamps. Replace hoses if cracked,
swollen, or damaged.
❑Replace fuel filter(s) (or every 12 months, whichever
occurs first).(2)
❑Check restraint system.(40)
❑Steering system service.(12)
❑Front and rear suspension service.(13)
❑Spring-to-axle U-bolts and shackle bolts service.(15)
❑Exhaust system service (or every 6 months,
whichever occurs first).(2) (3) (16)
❑Inspect door hinge pins and bushings and replace as
necessary.
❑Wheel bearing (grease type) service (and whenever
hubs are removed).(22) (36)
❑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)
❑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).(34)
❑Air brake system valve service (or every 3 months,
or every 900 hours, whichever occurs first).(37)
❑Air compressor dry element pleated paper air strainer
service (or every 2 months, or every 800 hours,
whichever occurs first).
❑C600, C700, and C800 Gasoline Engines Only:
Engine drive belts service (or every 12 months,
whichever occurs first).(17)
❑Thermostatically controlled engine cooling fan
service.(3) (19)
❑Shields and underhood insulation service.(3) (4) (20)
❑Rear axle air shift motor service.(10)
❑Air intake system service (or every 24 months,
whichever occurs first).(3) (4) (23)
6-17
❑Evaporative Control System service, if equipped, (or
every 24 months, whichever occurs first).(2) (24) †
❑Gasoline Engine: Air compressor remote mounted air
filter dry element pleated paper air strainer service
(or every 6 months or every 1800 hours, whichever
occurs first).
96,000 Miles (152 000 km)
❑Lubricate U-joints (or every 6 months, whichever
occurs first).
97,500 Miles (156 000 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)
❑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)
❑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).(34)
100,000 Miles (160 000 km)
❑Diesel Only: Inspect engine drive belt; replace as
necessary.
❑Gasoline Engine Only (Vehicles with GVW of
16,000 lbs or less): Spark plug service.(2) (25)
❑Change power steering fluid (or every 36 months,
whichever occurs first).(12)
❑Replace power steering reservoir filter element
(or every 24 months, whichever occurs first).
❑Wheel bearing (oil type) service (and whenever hubs
are removed).(22) (36)
❑Except four-wheel drive: Front axle service.(31)
❑Four-wheel drive only: Front axle service.(30)
❑Four-wheel drive only: Transfer case service.(30)
6-18
❑Rear axle service — Eaton®, Rockwell®, Spicer®
axles (or every 12 months, whichever occurs
first).(30)
❑Exhaust brake service, if equipped. Check for
excessive spindle free play and smooth operation.
Lubricate ball joint cap.
❑Inspect air compressor discharge port (or every
6 months or every 1,800 hours, whichever occurs
first).
❑Manual transmission (ZF 6-speed only) fluid
replacement (or every 48 months, whichever
occurs first).
❑Trailer brake hand control valve service (or every
12 months, or every 3,600 hours, whichever
occurs first).(35)
120,000 Miles (192 000 km)
❑C600, C700, and C800 Gasoline Engines Only:
Replace engine drive belts.
❑C400 and C500 Gasoline Engines Only: Engine drive
belts service (or every 12 months, whichever occurs
first).(17)
❑DURAMAX
®Diesel Only: Diesel Particulate Filter
(DPF) service. Then every 100,000 miles
(160 000 km).(7) (38)
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).
6-19
(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.
(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 5-82for 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.
6-22