
To reset the Engine Oil Life System, do the
following:
1. Turn the ignition key to RUN with the
engine off.
2. Fully apply and hold the brake pedal while
you fully press and release the accelerator
pedal, pausing slightly at each press and each
release, three times within five seconds.
3. Turn the key to OFF.
If the change engine oil light comes back on when
you start your vehicle, the Engine Oil Life
System has not reset. Repeat the procedure.
Engine Air Cleaner/Filter
The engine air
cleaner/filter is located
in the center of the
engine compartment.
When to Inspect the Engine Air
Cleaner/Filter
If your vehicle has an
air cleaner/filter change
indicator, inspect the
indicator at every
oil change and replace
the filter when the
indicator tells you to.
For vehicles without a change indicator, inspect
the air cleaner/filter at every oil change and
replace the filter at the first oil change after
25,000 miles (40 000 km).
How to Inspect the Engine Air
Cleaner/Filter
Locate the filter change indicator. When the
change indicator turns black or is in the red/orange
change area, replace the filter and reset the
indicator.
280

Power Steering Fluid
SeeScheduled Maintenance on page 363to
determine when to check your power steering fluid.
How To Check Power Steering Fluid
Check your power steering fluid only when the
engine is warm. If the engine is not warm, you
probably will not get an accurate reading.
If the fluid level is between the MIN (Minimum) and
MAX (Maximum) marks, you have enough. If you
need fluid, add only enough of the proper fluid to
bring it in between the MIN and MAX marks.
If your power steering fluid level is low, this can
cause the brake or service brakes soon warning
lights to come on. In addition, the steering
effort and emergency brake distance could
increase.If either light remains on after you have added
power steering fluid to the proper level, then shut
off the engine for 10 seconds. This should
reset the brake warning lights. If one or both lights
stay on, see “Hydraulic Brake System Warning
Lights” underBrake System Warning Light
on page 169for more information.
What to Use
To determine what kind of fluid to use, see
Part C: Recommended Fluids and Lubricants on
page 397.
Notice:When adding power steering uid or
making a complete uid change, always
use the proper uid. Failure to use the proper
uid can cause leaks and damage hoses
and seals.
295

When It Is Time for New Tires
Replace your tires when the tread depth is down
to 1/8 of an inch (3.2 mm) for the front tires,
or 1/16 of an inch (1.6 mm) for a rear tire. Also,
you need a new tire if:
•You can see cord or fabric showing through
the tire’s rubber.
•The tread or sidewall is cracked, cut or
snagged deep enough to show cord or fabric.
•The tire has a bump, bulge or split.
•The tire has a puncture, cut or other damage
that cannot be repaired well because of the
size or location of the damage.
{CAUTION:
Mixing tires could cause you to lose
control while driving. If you mix tires of
different types — like radial and
bias-belted tires — the vehicle may not
handle properly, and you could have a
crash. Be sure to use the same type of
tires all around.When you replace tires, make sure they are the
same size, load range, speed rating and
construction type (bias, bias-belted or radial) as
your original tires.
If your vehicle has four-wheel drive, the axle
differentials, propshafts and transfer case may be
damaged if tires of different sizes, brands or
tread types are installed on the front and rear
axles. That damage would not be covered under
your warranty.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned at
the factory to give you the longest tire life and
best overall performance.
Proper front wheel alignment must be maintained
in order to ensure efficient steering, good
directional stability, and prevent abnormal tire
wear. If you notice unusual tire wear or your
vehicle is pulling one way or the other, the
alignment may need to be reset. If you notice your
vehicle vibrating when driving on a smooth
road, your wheels may need to be balanced.
324

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)
❑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)
12,000 Miles (20 000 km)
❑Isuzu 6H Diesel Without Engine Oil Life System
Only: Change engine oil and filter (or every
12 months, or every 600 hours of engine
operation, whichever occurs first).(2)
❑Isuzu 6H Diesel With Engine Oil Life System
Only: Check oil life system (or every 12 months,
or every 600 hours of engine operation,
whichever occurs first). If engine oil and filter
are changed, reset system. See “Engine Oil
(DURAMAX
®/Isuzu Diesel)” in the Index.(2) (7)
364

15,000 Miles (24 000 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)
❑6.6L DURAMAX
®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)
❑6.6L DURAMAX
®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)
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Check fluid levels (or every 3 months,
whichever occurs first).(1) (5)
❑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 280for 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 280for more information.
❑DURAMAX
®/Isuzu Diesel Only: Replace fuel
filter (or every 750 hours of engine operation,
whichever occurs first).
❑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)
❑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)
365

❑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)
❑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).
22,500 Miles (36 000 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)
❑Inspect door hinge pins and bushings and
replace as necessary.
❑Cooling system service. Clean the cooling
system filter 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)
❑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)
366

❑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 intake system service (or every 24 months,
whichever occurs first).(3) (4) (23)
❑Evaporative Control System service,
if equipped, (or every 24 months,
whichever occurs first).(2) (24) †
❑Rear axle air shift motor service.(10)24,000 Miles (40 000 km)
❑Isuzu 6H Diesel Without Engine Oil Life System
Only: Change engine oil and filter (or every
12 months, or every 600 hours of engine
operation, whichever occurs first).(2)
❑Isuzu 6H Diesel With Engine Oil Life System
Only: Check oil life system (or every 12 months,
or every 600 hours of engine operation,
whichever occurs first). If engine oil and filter
are changed, reset system. See “Engine Oil
(DURAMAX
®/Isuzu Diesel)” in the Index.(2) (7)
❑Lubricate U-joints (or every 6 months,
whichever occurs first).
367

30,000 Miles (48 000 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)
❑6.6L DURAMAX
®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)
❑6.6L DURAMAX
®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: 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 280for 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 280for more information.
❑DURAMAX
®/Isuzu 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)
❑Replace fuel filter(s) (or every 12 months,
whichever occurs first).(2)
❑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)
368