ApplicationCapacities
English Metric
Cooling System – C6/C7/C8 Manual Transmission
7.2L L6 Engine 30.4 qt 28.8 L
7.2L L6 Engine with A/C and Increased Cooling 33.9 qt 32.1 L
Isuzu 6H Engine (207–275 hp) 32.7 qt 31.0 L
Isuzu 6H Engine (207–275 hp) with A/C and Increased
Cooling35.9 qt 34.0 L
Isuzu 6H Engine (300 hp) 36.0 qt 34.1 L
Isuzu 6H Engine (300 hp) with A/C and Increased Cooling 36.0 qt 34.1 L
8.1L V8 Engine 33.3 qt 31.5 L
8.1L V8 Engine with A/C and Increased Cooling 34.9 qt 33.0 L
Engine Oil with Filter
6.6L V8 Engine 14.6 qt 13.8 L
7.2L L6 Caterpillar
®C7 Engine 30.0 qt 28.4 L
Isuzu 6H
1Engine 23.8 qt 22.5 L
8.1L V8 Engine 10.0 qt 9.4 L
Check fill level on the oil indicator after initial fill to make sure it is actually full. Oil level may vary depending on
vehicle option content.
1Additional oil is required with auxiliary oil filter systems. Make sure to add enough extra oil to fill the auxiliary oil
filter system. For vehicles equipped with the LUBERFINER 750-C, add 14 quarts (13.25 L).
5-103
ApplicationCapacities
English Metric
Transmission Fluid, Manual
ES052-7, ES066-7 22.0 pt 10.4 L
FS5205A 12.5 pt 5.9 L
FSO8406, FS6305A, FS6305B, FS6406, FS5406A 19.5 pt 9.2 L
FS4205A, FS4205B 11.5 pt 5.4 L
RT6609 12.0 pt 5.7 L
RT8709 26.0 pt 12.3 L
RT8908LL 28.0 pt 13.2 L
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck the fluid level after filling.
Engine Specifications
Engine RPO Type
6.6L V8 DURAMAX®LMM Common Rail Fuel System
7.2L L6 Caterpillar
®C7 LF6Hydraulic/Electronic Unit Injector
Fuel System
7.8L L6 Isuzu 6H LF8 Common Rail Fuel System
8.1L V8 VORTEC™ L18Single Port Fuel Injector Fuel
System
5-107
Maintenance Schedule
Introduction
Important: Keep engine oil at the proper level and
change as recommended.
Have you purchased the GM Protection Plan? The Plan
supplements the vehicle warranties. See the Warranty
and Owner Assistance booklet or your dealer/retailer for
details.
Maintenance Requirements
Maintenance intervals, checks, inspections and
recommended fluids and lubricants as prescribed in this
manual are necessary to keep this vehicle in good
working condition. Any damage caused by failure to
follow scheduled maintenance may not be covered by
the vehicle warranty.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep
the vehicle in good working condition, but also helps the
environment. Improper vehicle maintenance can even
affect the quality of the air we breathe. Improper
fluid levels or the wrong tire inflation can increase the
level of emissions from the vehicle. To help protect
the environment, and to keep the vehicle in good
condition, be sure to maintain the vehicle properly.
6-2
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
❑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)
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)
❑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)
❑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 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).
❑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)
6-6
❑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).
❑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)
6-7
❑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 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)
❑Lubricate U-joints (or every 6 months, whichever
occurs first).
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)
❑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: 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.
6-8