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Cooling System Capacity
The following approximate capacities are given in English and metric conversions. Please refer toPart C:
Recommended Fluids and Lubricants on page 6-29for more information.
ApplicationCapacities
English Metric
C4/C5 Models
8.1L with manual transmission 30.1 quarts 28.5 liters
8.1L with automatic transmission 29.8 quarts 28.2 liters
6.6L with manual transmission 27.6 quarts 26.1 liters
6.6L with automatic transmission 27.3 quarts 25.8 liters
C6/C7/C8 Models
8.1L with manual transmission 33.3 quarts 31.5 liters
8.1L with manual transmission, air conditioning and
increased cooling34.9 quarts 33.0 liters
8.1L with automatic transmission 32.5 quarts 30.8 liters
7.8L 200–230 hp engine with manual transmission 31.6 quarts 29.9 liters
7.8L 200–230 hp engine with manual transmission, air
conditioning and increased cooling35.3 quarts 33.4 liters
C6/C7/C8 Models
7.8L 200–215 hp engine with automatic transmission 33.7 quarts 31.9 liters
7.2L 175–230 hp engine with manual transmission 29.3 quarts 27.7 liters
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ApplicationCapacities
English Metric
7.2L 175–230 hp engine with manual transmission, air
conditioning and increased cooling33.0 quarts 31.2 liters
7.2L 175–210 hp engine with automatic transmission 31.4 quarts 29.7 liters
7.8L 250–275 hp engine with manual transmission 34.9 quarts 33.0 liters
7.8L 250–275 hp engine with manual transmission, air
conditioning and increased cooling35.4 quarts 33.5 liters
7.8L 230–275 hp engine with automatic transmission 33.3 quarts 31.5 liters
7.2L 250–300 hp engine with manual transmission 32.8 quarts 31.0 liters
7.2L 250–300 hp engine with manual transmission, air
conditioning and increased cooling33.3 quarts 31.5 liters
7.2L 250–300 hp engine with automatic transmission 31.2 quarts 29.5 liters
Air Conditioning Refrigerant R134a 2.1 lbs. 1.0 kg
It is recommended that service work on your air conditioning system be performed by a qualified technician.
R134a 2.1 lbs. (1.0 kg)
Use Refrigerant Oil, R143a Systems
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Engine Oil with Filter Capacity
ApplicationCapacities
English Metric
7.2L** 30.0 quarts 28.4 liters*
8.1** 6.5 quarts 6.1 liters
7.8L** 23.8 quarts 22.5 liters
6.6L** 14.6 quarts 13.8 liters
*Additional 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).
**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.
Fuel Tank Capacity
ApplicationCapacities
English Metric
C4/C5 Models
Standard*
Optional
Optional
Optional40 gallons
40 gallons
60 gallons
80 gallons151.4 liters
151.4 liters
227.1 liters
302.8 liters
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Part Engine
(RPO Code)GM Part
NumberACDelco®Part
NumberOther Part
Numbers
Engine Air Cleaner/Filter
6.6L (LB7/LLY) (C4/C5 Models)
6.6L (LB7/LLY) (C6/C7/C8 Models)
7.2L (LG5)
7.8L (LG4) (C4/C5 Models)
7.8 L (LG4) (C6/C7/C8 Models)
8.1L (L18)88937527
88937548***
—
8837527
88937548***
25313349—
—
—
—
—
A1518C—
—
Donaldson P522606
—
—
—
Engine Oil Filter
6.6L (LB7/LLY)
7.2L (LG5)
7.8L (LG4)
8.1L (L18)88917036
—
94392475
89028862PF2232
—
—
PF454—
CAT 1R0739
—
—
Fuel Filter
6.6L (LB7/LLY)
7.2L (LG5)
7.8L (LG4)
8.1L (L18)97256734
—
94392474
——
915 Primary**
—
GF626*—
—
—
—
Power Steering Fluid Filter
6.6L (LB7/LLY)
7.2L (LG5)
7.8L (LG4)
8.1L (L18)88892858
88892858
88892858
88892858—
—
—
——
—
—
—
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Part Engine
(RPO Code)GM Part
NumberACDelco®Part
NumberOther Part
Numbers
Pressure Caps
6.6L (LB7/LLY)
7.2L (LG5)
7.8L (LG4)
8.1L (L18)15075118
—
15075118
15997145—
—
—
——
—
—
—
Secondary Fuel Filter
6.6L (LB7/LLY)
7.2L (LG5)
7.8L (LG4)
8.1L (L18)—
—
15098649
25055052—
—
—
——
CAT 1R0751
—
—
Spark Plugs
6.6L (LB7/LLY)
7.2L (LG5)
7.8L (LG4)
8.1L (L18)—
—
—
——
—
—
41-983—
—
—
—
*Optional Davco (K28) D350921 spin-on type filter located on driver’s side frame rail.
**Optional Cold Weather (KUK) Racor B6484GM spin-on type filter located on driver’s side frame rail.
***Optional air filter (GM Part No. 88937525) for C6/C7/C8 Models. Fits inside standard size filter (GM Part No.
88937548) listed previously.
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Engine Drive Belt Routing
8.1L EngineDURAMAX™ Diesel
Engine
Caterpillar Diesel Engine
5-103
Page 312 of 366

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 your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your dealer
for details.
Maintenance Requirements
Maintenance intervals, checks, inspections and
recommended fluids and lubricants as prescribed in this
manual are necessary to keep your vehicle in good
working condition. Any damage caused by failure
to follow scheduled maintenance may not be covered by
warranty.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
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 your vehicle. To help protect
our environment, and to keep your vehicle in good
condition, be sure to maintain your vehicle properly.
6-2
Page 314 of 366

Part A: Scheduled Maintenance
Services
In this part are scheduled maintenance services which
are to be performed at the mileage intervals specified.
Using Your Maintenance Schedule
We at General Motors want to help keep your vehicle in
good working condition. But we do not know exactly
how you will drive it. You may drive very short distances
only a few times a week. Or you may drive long
distances all the time in very hot, dusty weather. You
may use your vehicle in making deliveries or in
many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may 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 your vehicle in good condition,
see your dealer.
This part tells you the maintenance services you should
have done and when to schedule them.
When you go to your dealer for your service needs, you
will know that GM-trained and supported service
people will perform the work using genuine GM parts.The proper fluids and lubricants to use are listed in
Part C. Make sure whoever services your 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. You will find limits on your vehicle’s GVW
Rating label. SeeLoading Your Vehicle on
page 4-33.
•are driven on reasonable road surfaces within legal
driving limits.
•use the recommended fuel. SeeWhat Fuel to Use
on page 5-8.
Scheduled Maintenance
Supplements
If your vehicle has a Caterpillar®diesel engine, your
owner’s manual is supplemented by the Caterpillar®
Diesel Engine Operation & Maintenance Manual. If your
vehicle has an Allison transmission, your owner’s
manual is supplemented by an Allison
Transmission
®Operator’s Manual. Always refer to these
manuals for related maintenance services.
6-4