Page 272 of 366

Secondary Fuel Filter and Water
Separator/Heater
If you have a Caterpillar®
diesel engine, you may
also have this spin-on filter
and fuel separator/heater.
It will be mounted in
the engine compartment
on the driver’s side of
the vehicle.
It has a metal drain bowl at the bottom. Occasionally,
check the bowl for any water or particles.
To check or drain the bowl, do the following:
•Shut off the engine.
•Push up on the spring loaded drain valve until clear
fuel is flowing from the valve.
The particles or water will drain out first. SeeEngine Oil
(Caterpillar
®Diesel Engine) on page 5-20orEngine
Oil (Gasoline Engine) on page 5-20orEngine Oil
(DURAMAX™ Diesel) on page 5-25for proper disposal
procedures.
Automatic Ether Injection System
If you have a Caterpillar®
diesel engine, you may
have this feature. The
ether cylinder is located in
the engine compartment
on the driver’s side of
the vehicle.
To change an empty ether cylinder, follow these steps.
1. Loosen the screw head on the cylinder-to-bracket
clamp.
2. Spread the clamp apart.
3. Clean any dirt from the neck of the cylinder and the
top of the valve before you take out the cylinder.
4. Check the inside of the valve for any foreign matter.
Clean the valve as necessary.
5. Cover the valve to protect it from dirt and take out
the cylinder.
5-66
Page 301 of 366
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
5-95
Page 302 of 366
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
5-96
Page 307 of 366
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—
—
—
——
—
—
—
5-101
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 315 of 366

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 have a computer that lets you
know when to change your engine oil. This is not
based on mileage, but on engine revolutions and engine
operating temperature. When the computer has
calculated that the oil needs changing, the GM Oil Life
System will indicate that a change is necessary.
The “Footnotes” at the end of this Maintenance
Schedule further explain maintenance services.
SeeService Publications Ordering Information on
page 7-7.
100 Miles (160 km)
❑Wheel stud nut service.(46)
1,000 Miles (1 600 km)
❑Wheel stud nut service.(46)
❑Rear axle air shift motor service.(11)
7,500 Miles (12 000 km)
❑Gasoline Engine Only: Check Oil Life System. If
engine oil and filter are changed, reset system. See
“Engine Oil (Gasoline Engine)” in the Index.(3) (9)
❑Check fluid levels (or every 3 months, whichever
occurs first).(1) (6)
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(12)
❑Wheels and tires service.(15)
❑Hydraulic brake service (or every 6 months, whichever
occurs first).(7) (46)
❑Parking brake service (or every 6 months, whichever
occurs first).(8)
❑Air brake service (or every 6 months, whichever
occurs first).(39)
❑Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first).(40)
❑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).(41)
❑Trailer brake hand control valve service (or every
3 months, or every 900 hours, whichever occurs
first).(42)
6-5
Page 316 of 366

10,000 Miles (16 000 km)
❑DURAMAX™ Diesel Only: Change engine oil
and filter (or every 12 months, whichever occurs
first).(2) (3)
15,000 Miles (24 000 km)
❑Gasoline Engine Only: Check Oil Life System.
If engine oil and filter are changed, reset system. See
“Engine Oil (Gasoline Engine)” in the
Index.(3) (9)
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(12)
❑Check fluid levels (or every 3 months, whichever
occurs first).(1) (6)
❑Gasoline Engine: Inspect engine air cleaner filter if
you are driving in dusty conditions and replace
filter if necessary. 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 5-30for more
information.† (3)
❑DURAMAX™ Diesel Only: Replace fuel filter.
❑Steering system service.(13)
❑Front and rear suspension service.(14)
❑Spring-to-axle U-bolts and shackle bolts service.(16)❑Exhaust system service (or every 6 months,
whichever occurs first).(3) (4) (17)
❑Wheels and tires service.(15)
❑Hydraulic brake service (or every 6 months,
whichever occurs first).(7) (46)
❑Parking brake service (or every 6 months, whichever
occurs first).(8)
❑Air brake service (or every 6 months, whichever
occurs first).(39)
❑Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first).(40)
❑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).(41)
❑Trailer brake hand control valve service (or every
3 months, or every 900 hours, whichever occurs
first).(42)
❑Thermostatically controlled engine cooling fan
service.(4) (20)
❑Shields and underhood insulation service.(4) (5) (21)
6-6
Page 317 of 366

20,000 Miles (32 000 km)
❑DURAMAX™ Diesel Only: Change engine oil
and filter (or every 12 months, whichever occurs
first).(2) (3)
❑Air compressor dry element pleated paper air strainer
service (or every 2 months or every 800 hours,
whichever occurs first).
22,500 Miles (36 000 km)
❑Gasoline Engine Only: Check Oil Life System. If
engine oil and filter are changed, reset system. See
“Engine Oil (Gasoline Engine)” in the Index.(3) (9)
❑Check fluid levels (or every 3 months, whichever
occurs first).(1) (6)
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(12)
❑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.
❑Wheel bearing (grease type) service (or every
24 months, whichever occurs first, and whenever hubs
are removed).(23) (46)❑Wheels and tires service.(15)
❑Hydraulic brake service (or every 6 months, whichever
occurs first).(7) (46)
❑Parking brake service (or every 6 months, whichever
occurs first).(8)
❑Air brake service (or every 6 months, whichever
occurs first).(39)
❑Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first).(40)
❑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).(41)
❑Trailer brake hand control valve service (or every
3 months, or every 900 hours, whichever occurs
first).(42)
❑Air intake system service (or every 24 months,
whichever occurs first).(4) (5) (24)
❑Evaporative Control System service (if equipped) (or
every 24 months, whichever occurs first).(3) (26) †
❑Rear axle air shift motor service.(11)
6-7