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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).
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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
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Normal Maintenance Replacement Parts
Maintenance Replacement Parts
Replacement parts identified by name, part number, or specification can be obtained from your dealer.
Part GM Part Number ACDelco Part Number
Air Compressor Filter
Haldex compressor (8.1L Engine Only)88915425 A507CF
Engine Air Cleaner/Filter
6.6L V8 (C4/C5 Models) 19152817 A3102C
7.2L L6; Isuzu 6H (C6/C7/C8 Models) with Standard Air
Cleaner88937525 A2031C
7.2L L6; Isuzu 6H (C6/C7/C8 Models) with Heavy Duty Air
Cleaner88937525
1A2031C
8.1L V8 (C4/C5 Models) 88937527 A2032C
8.1L V8 (C6/C7/C8 Models) with Heavy Duty Air Cleaner 88937525 A2031C
8.1L V8 (C6/C7/C8 Models) with Standard Air Cleaner 88937545 A2034C
Engine Oil Filter
6.6L V8 88917036 PF2232
7.2L L6 — 1R-1807
2
Isuzu 6H 94392475 —
8.1L V8 25324052 PF454
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Engine Drive Belt Routing
A. Air Conditioning Compressor.
B. Dual Generators.A. Air Conditioning Compressor.
B. Air Brake Compressor. 8.1L V8 Engine (C4, C5)
8.1L V8 Engine (C6,C7,C8)
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A. Dual Generators. A. Air Conditioning Compressor.6.6L V8 Duramax Diesel Engine
Isuzu 6H Diesel Engine
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A. Air Conditioning Compressor.7.2L I6 Caterpillar Diesel Engine
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Page 316 of 376

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.
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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.
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