Thresholds can also vary with specific vehicle design.
Frontal airbags are not intended to inflate during vehicle
rollovers, rear impacts, or in many side impacts.
In any particular crash, no one can say whether an
airbag should have inflated simply because of the
damage to a vehicle or because of what the repair costs
were. For frontal airbags, inflation is determined by
what the vehicle hits, the angle of the impact, and how
quickly the vehicle slows down.
What Makes an Airbag Inflate?
In a deployment event, the sensing system sends an
electrical signal triggering a release of gas from the
inflator. Gas from the inflator fills the airbag causing the
bag to break out of the cover and deploy. The inflator, the
airbag, and related hardware are all part of the airbag
module.
Frontal airbag modules are located inside the steering
wheel and instrument panel.
How Does an Airbag Restrain?
In moderate to severe frontal or near frontal collisions,
even belted occupants can contact the steering wheel
or the instrument panel. In moderate to severe side
collisions, even belted occupants can contact the inside
of the vehicle.
Airbags supplement the protection provided by safety
belts. Frontal airbags distribute the force of the impact
more evenly over the occupant’s upper body, stopping
the occupant more gradually.
But airbags would not help in many types of collisions,
primarily because the occupant’s motion is not toward
those airbags. SeeWhen Should an Airbag Inflate? on
page 1-52for more information.
Airbags should never be regarded as anything more
than a supplement to safety belts.
1-53
Engine Starter Over-Crank
Protection
The vehicle may have an engine starter over-crank
protection system. If the starter motor overheats and
shuts off due to over-cranking, the motor must cool down
before it will reset and allow starter operation. It can take
up to six minutes before the starter will work again.
Starting the Gasoline Engine
The 8th digit of the Vehicle Identification Number (VIN)
shows the code letter for the engine. Use this number
to verify the type of engine in the vehicle. SeeVehicle
Identification Number (VIN) on page 5-94. Follow
the proper steps to start the engine.
To start a diesel engine, seeStarting the Diesel Engine
on page 2-14.
Automatic Transmission
Set the parking brake and move the shifter to N (Neutral)
or P (Park), if so equipped. The engine will not start in
any other position.
Manual Transmission
Set the parking brake, shift to N (Neutral) and hold the
clutch pedal to the floor while starting the engine.
Starter Motor Operation
•The starter motor will disengage if you release the
key or the engine reaches a predetermined engine
speed.
•To prevent overheating, the starter motor will
disengage after continuously operating for
15 seconds. You must release the key from the
start position to re-engage the starter.
•The starter motor will not engage if the engine is
already running.
•The starter motor will disengage if, after
two seconds, the starter pinion gear does not
engage the flywheel or there is no engine rpm
signal from the engine speed sensor.
2-12
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
❑Diesel Engine: Inspect engine air cleaner filter change
indicator. If necessary, replace the filter. If vehicle is
driven in dusty/dirty conditions, inspect filter change
indicator at every engine oil change. SeeEngine Air
Cleaner/Filter on page 5-38for more information.
❑Diesel Only: Replace fuel filter (or every 750 hours of
engine operation, whichever occurs first).
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Gasoline Engine Only: 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)
❑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 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).
6-9
❑Gasoline Engine: Inspect engine air cleaner filter.
If necessary, replace the filter. If vehicle is driven in
dusty/dirty conditions, inspect filter at every engine oil
change. SeeEngine Air Cleaner/Filter on page 5-38
for more information.
❑Diesel Engine: Inspect engine air cleaner filter change
indicator. If necessary, replace the filter. If vehicle is
driven in dusty/dirty conditions, inspect filter change
indicator at every engine oil change. SeeEngine Air
Cleaner/Filter on page 5-38for more information.
❑Diesel Only: Replace fuel filter (or every 750 hours of
engine operation, whichever occurs first).
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Gasoline Engine Only: Replace fuel filter(s) (or every
12 months, whichever occurs first).(2)
❑Inspect door hinge pins and bushings and replace as
necessary.
❑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)
❑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)
6-13
90,000 Miles (144 000 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)
❑DURAMAX/Isuzu Diesel Without Engine Oil Life
System Only: Change engine oil and filter (or every
12 months, or every 750 hours of engine operation,
whichever occurs first).(2) (39)
❑DURAMAX/Isuzu Diesel With Engine Oil Life System
Only: Check oil life system. If engine oil and filter are
changed, reset system. See “Engine Oil (DURAMAX/
Isuzu Diesel)” in the Index.(2) (9)
❑Check fluid levels (or every 3 months, whichever
occurs first).(1) (5)
❑Gasoline Engine: Replace engine air cleaner filter.
SeeEngine Air Cleaner/Filter on page 5-38for more
information.
❑Diesel Engine: Inspect engine air cleaner filter change
indicator. If necessary, replace the filter. If vehicle is
driven in dusty/dirty conditions, inspect filter change
indicator at every engine oil change. SeeEngine Air
Cleaner/Filter on page 5-38for more information.
❑Diesel Only: Replace fuel filter (or every 750 hours of
engine operation, whichever occurs first).
❑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.
❑Gasoline Engine Only: 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)
6-17
❑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)
❑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)
6-19
(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