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Item Number Item Remarks
4 Pivot Points and Hinges Apply chassis lubricant.
5 Pivot Points and Hinges Apply chassis lubricant.
6 Slack Adjuster** One fitting.
7Brake Cam Roller Pins at interface of pin
and shoe**Apply engine oil.
8 Front Steering KnucklesOne fitting each side, lower bushing.
(Hand-operated grease gun only.) Hand-pack
upper bearing.
9 Front Wheel Bearings Hand-pack or lubricate.
10 Steering Tie Rod Ends One fitting each end.
11 Spring Slip Pads* (Multi-Leaf Only) Apply chassis lubricant.
12 Clutch Release Bearing* Cup or fitting.
13 Battery Terminal (except “ST” type) Keep coated with petroleum jelly.
14 Transmission Fill to level of filler plug.
15 Propshaft U-JointsLubricate with GM Part No. 1051344 Wheel
Bearing Lubricant.
16 Parking Brake Clevis Pin$ Apply chassis lubricant.
17 Parking Brake Lever Pivot*, $ Apply chassis lubricant.
18Clutch Release Cross Shaft, Master
Cylinder$Apply chassis lubricant, fill to 1/4 inch (6 mm)
below opening.
19 Release Bearing, Clutch Cross Shaft Two fittings, apply chassis lubricant.
20 Clutch Release Fork Two fittings.
* Applies to some vehicles.
** Applies to air brakes only.
$ Applies to hydraulic brakes only.
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Tandem Axle ModelsItem
Number Item Remarks
1 Brake Camshafts One fitting each.
2 Propshaft U-JointOne fitting each
joint. Lubricate
with GM Part
No. 1051344, Wheel
Bearing Lubricant
3 Rear AxlesFill to level of
filler plug.
4Brake Shoe
Roller PinsApply engine oil
at pin to shoe joint
only.
5 Rear Spring PinOne fitting
each side.
Battery
Your vehicle has one or more maintenance free
batteries. When it is time for a new battery, be sure
it has the replacement number shown on the
original battery’s label. We recommend an
ACDelco
®replacement battery.
Warning:Battery posts, terminals, and related
accessories contain lead and lead compounds,
chemicals known to the State of California
to cause cancer and reproductive harm. Wash
hands after handling.
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Page 320 of 430
If your vehicle has
oil-filled hubs,
occasionally check to
see if they have enough
oil. You can tell if
there is oil there by
using the circular gage
on the sight glass.
If there isn’t, clean the rubber fill plug in the center
of the glass, and then remove it. Be careful not
to allow any dirt or water to get into the oil.
Add enough of the recommended oil to bring it up
to the level mark that you’ll see on the glass.Refer to your Maintenance Schedule for the
proper oil to use.
When you fill the hub, check the glass again after
driving a short distance. It takes a while for the
oil to flow through the system, and you may
find that you have to add a little more to fill it to
the proper level. Be sure not to overfill the hub.
Air Conditioning System
Every now and then, have your dealership check
your air conditioning system to be sure it has
not lost any cooling ability. If you think the system
is not working properly, have your GM dealer
check it out as soon as possible.
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Page 348 of 430
ApplicationCapacities
English Metric
7.2L 250 - 300 hp Engine 32.8 qt 31.0 L
7.2L 250 - 300 hp Engine with A/C and Increased Cooling 33.3 qt 31.5 L
Isuzu 6H 200 - 230 hp Engine 31.6 qt 29.9 L
Isuzu 6H 200 - 230 hp Engine with A/C and Increased
Cooling35.3 qt 33.4 L
Isuzu 6H 250 - 300 hp Engine 34.9 qt 33.0 L
Isuzu 6H 250 - 300 hp Engine with A/C and Increased
Cooling35.4 qt 33.5 L
8.1L 225 - 295 hp Engine 33.3 qt 31.5 L
8.1L with A/C and Increased Cooling 34.9 qt 33.0 L
Engine Oil with Filter
6.6L 14.6 qt 13.8 L
7.2L 30.0 qt 28.4 L
Isuzu 6H
123.8 qt 22.5 L
8.1L 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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Page 360 of 430

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.
How This Section is Organized
This maintenance schedule is divided into
four parts:
“Part A: Scheduled Maintenance Services”
explains what to have done and how often. Some
of these services can be complex, so unless
you are technically qualified and have the
necessary equipment, you should let your GM
dealer’s service department do these jobs.
Your GM dealer has GM-trained and supported
service people that will perform the work using
genuine GM parts.
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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)
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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)
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❑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