2003 CHEVROLET C/K air condition

7-13
90,000 Miles (144 000 km)

Gasoline Engine Only: Check Oil Life System.
If engine oil and filter are changed, reset system.
See ªEngine Oilº in the Index. (3)(9)

DURAMAX Diesel Only: Change engine
oil and filter (or every 12 months, whichever
occurs first). (2)(3)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(6)

DURAMAX Diesel Only: Replace fuel filter.

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Cooling system service. Clean the cooling system
filler 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)

Replace fuel filter(s) (or every 12 months, whichever
occurs first). (3)
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)

Inspect door hinge pins and bushings and replace
as necessary.

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)

C600, C700 and C800 Gasoline Engines Only:
Engine drive belts service (or every 12 months,
whichever occurs first). (18)

Thermostatically controlled engine cooling fan
service. (4)(20)

Shields and underhood insulation service. (4)(5)(21)

Rear axle air shift motor service. (11)

Air intake system service (or every 24 months,
whichever occurs first). (4)(5)(24)
(Continued)

7-16
Footnotes

= The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the maintenance
be recorded.
(1) = If your vehicle has an Allison automatic
transmission, your GM owner's manual is supplemented
by an Allison Transmission Operator's Manual. Always
refer to these manuals for related maintenance services.
(2) = Refer to the Caterpillar Diesel Engine Operation
and Maintenance Manual for oil recommendations and
change intervals.
(3) = An Emission Control Service.
(4) = A Noise Emission Control Device.
(5) = Applies only to vehicles sold in the United States.(6) = Check fluid level in brake master cylinder, power
steering pump, axle, transmission and hydraulic spring
parking brake pump (if equipped). A low fluid level in
the brake master cylinder can indicate worn brake
linings and should be checked accordingly.
(7) = Inspect brake lines and hoses for proper hook
-up,
binding, leaks, cracks, chafing, etc. Inspect disc brake
pads for wear and rotors for surface condition. Inspect
caliper assemblies. Check brake pedal for excessive free
play or travel (or every 6 months, whichever occurs first)
and have serviced if needed. Check brakes more often if
driving habits and conditions result in frequent braking.
(8) = Inspect parking brake drum and linings for wear or
cracks and check linkage and adjustment.
(9) = This vehicle has the GM Oil Life System. This
system will show you when to change the engine oil and
filter
-- usually between 3,000 miles (5 000 km) and
7,500 miles (12 000 km) since your last oil change.
Under severe conditions, the indicator may come on
before 3,000 miles (5 000 km). Never drive your vehicle
more than 7,500 miles (12 000 km) or 12 months
without an oil and filter change.
Remember to reset the Oil Life System whenever the oil
is changed. For more information, see ªChange Oil
Lightº in the Index.

7-17
(10) = Check clutch pedal for free travel. Press pedal
by hand until resistance is felt. Free travel should be
maintained at 1.5 to 2 inches (38 to 51 mm) measured
at the clutch pedal pad. Make checks at 1,000 miles
(1 600 km) and then at every 7,500 mile (12 000 km)
interval thereafter.
(11) = Inspect rear axle air shift motor for fluid leaks.
Remove plug to check fluid level. Inspect air lines and
hoses for proper hook
-up, binding, leaks, etc. Inspect at
3,000 miles (5 000 km) and 22,500 miles (36 000 km)
and then every 22,500 miles (36 000 km) thereafter.
(12) = Chassis Lubrication Service: Lubricate all grease
fittings in front suspension, front axle and steering
linkage. DO NOT lubricate kingpin bushings with air
pressure equipment; instead, use a hand grease gun to
ensure complete purge and eliminate sealer cap
distortion. Lubricate transmission and shift linkage,
hood latches and hood hinges, parking brake lever pivot,
clevis pins and linkage, disc brake caliper rails, clutch
linkage and release bearing (if equipped), bearing pads,
propshaft universal joints, brake camshaft bracket, slack
adjusters, pedal shaft, clutch cross shaft and clutch pedal
springs. Lubricate suspension, axle and steering linkage
more often when operating under dusty or muddy
conditions and in excessive off
-road use.(13) = Check steering system:

Look for damaged, loose or missing parts. Also look
for parts showing signs of wear or lack of lubrication.
Replace parts as needed. Also check steering gear
mounting bolts, pitman arm nut, gear housing upper
cover and side cover attaching bolts, steering column
mounting bolts and cardan joint clamp bolts; tighten
if necessary. (See service manual.)

Inspect power steering hoses, tubes and fittings for
leaks. Hoses and lines must not be twisted, kinked or
tightly bent. Make sure clips, clamps, supporting
tubes and hoses are in place and properly secured.

Check steering gear for leakage around pitman shaft
and housing. If leakage is evident (lubricant oozing
out, not just oily film), leak should be corrected
immediately.
(14) = Check front and rear suspension. Look for
damaged, loose or missing parts or parts showing signs
of wear or lack of lubrication. Replace parts as needed.

7-18
(15) = Adjust tire pressures as indicated on the GVW
Rating label for optimum tire life. See ªTiresº in the
Index for further details. Check tires for excessive or
abnormal wear or damage. Also check for damaged
wheels. Replace wheels and/or tires as needed.
(16) = Check spring
-to-axle U-bolts and shackle
bolts for proper torque. See the service manual for
torque sequence and specifications. When parts are
replaced, the torque must be checked and adjusted
more often during the first 6,000 miles (10 000 km).
Check torque at 500 miles (800 km) and 2,000 miles
(3 000 km) after first use of parts.
(17) = Check complete exhaust system and cab areas
near the exhaust system for broken, damaged, missing or
out
-of-position parts. Also inspect for open seams,
holes, loose connections or other conditions which could
let exhaust fumes seep into the driver compartment.
Needed repairs should be made at once. To help
maintain system integrity, replace exhaust pipes
whenever a new muffler is put on.
(18) = Check all gasoline engine drive belts for cracks,
fraying and wear. Replace as needed.(20) = With the engine off and below normal operating
temperature, check to see that the thermostatically
controlled engine cooling fan can be rotated by hand on
viscous
-operated drives. Replace as needed.
(21) = Check shields and underhood insulation for
damage or looseness. Adjust or replace as needed.
(23) = Wheel bearing service:

Grease type
-- Clean, inspect and lubricate with the
proper wheel bearing grease at designated intervals
or when hubs are removed. See ªRecommended
Fluids and Lubricantsº in the Index.

Oil
-filled type -- Some wheel bearings are lubricated
by rear axle lubricant. When you have oil
-filled
hubs, use lubricant identical to that used in your rear
axle. Lubricant change intervals are the same for
front and rear axles. However, you must maintain oil
level at the OIL LEVEL mark between change
intervals. See ªRecommended Fluids and
Lubricantsº in the Index.
(24) = Check the air intake system installation to see that
gaskets are seated properly and all hose connections,
fasteners and other components are tight. Tighten
connections and fasteners or replace parts as required.

7-20
(39) = Air brake service:

Inspect brake lines and hoses for proper hook
-up,
binding, leaks, cracks, chafing, etc. Inspect drum
brake linings for wear or cracks. Inspect other brake
parts at each wheel, including drums, wheel
cylinders and piston heat shields, boots and wheel
speed sensor wiring. Check brake pedal for excessive
free play or travel (or every 6 months, whichever
occurs first) and have serviced if needed. Check
brakes more often if driving habits and conditions
result in frequent braking. Replace air dryer cartridge
only if excessive oil or moisture is present. A small
amount of oil in the system is normal and should not
be considered as a reason to replace the cartridge.

Test air lines for leaks; tighten as needed. Replace
compressor filter.

Inspect air parking brake chamber for leaks and
damage. Inspect lines and hoses for leaks, cracks,
chafing, etc. Also check all attachments for
tightness, wear or damage. Note: The spring brake
section of the rear brake diaphragms are
non
-serviceable.

Replace the air compressor filter element, mounted
on the air compressor. For remote air compressor
intake service, refer to engine air cleaner filter
replacement.
Remove, disassemble, clean and inspect the safety
valve, standard brake chamber, quick release valve,
quick release/double check valve combination,
parking brake control valve, double check valve,
pressure protection valve and alcohol injector.

Remove, disassemble and clean the application
valve; replace parts showing wear.

Remove, disassemble, clean and inspect the spring
brake control valve; replace rubber parts.
(40) = Clean and lubricate air brake automatic slack
adjuster. Check pushrod travel and auto adjustment
operation. Have serviced if needed.
(41) = Air brake chamber service: Check operation,
mounting, clamps and air lines and check for leaks.
(42) = Trailer brake hand control valve service: Check
operation; lubricate cam and follower.
(46) = Tighten the wheel stud nuts to the specified
torque values at 100 miles (160 km). Thereafter, tighten
them 1,000 miles (1 600 km) after each time the wheel
is removed. See ªTightening the Wheel Nutsº in
the Index.

7-24
Automatic Transmission Shift Indicator Check
Check that the indicator points to the gear chosen.
Steering Check
Be alert for any changes in steering action, abnormal
front tire wear or steering wheel position. An inspection
or service is needed when the steering wheel is harder to
turn or has too much free play, or if there are strange
sounds when turning or parking.
Brake System Check
Be alert to illumination of the low air warning lamp or
for the tone alarm, or changes in braking action, such
as repeated pulling to one side, unusual sounds when
braking or increased brake pedal travel. Make sure air
brake system reservoirs are drained daily with full
system air pressure, and check system for leaks. Any
of these conditions could indicate the need for brake
system inspection and/or service.Engine Cooling System Service
Inspect the hoses and have them replaced if they are
cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the outside
of the radiator and air conditioning condenser. To help
ensure proper operation, a pressure test of the cooling
system and pressure cap is recommended at least once
a year.
Exhaust System Check
Be alert for any changes in the sound of the exhaust
system or any smell of fumes. These are signs the
system may be leaking. Have it checked and/or repaired
at once. Refer to ªEngine Exhaustº and ªRunning Your
Engine While You're Parkedº in the Index.
Windshield Wipers and Washers Check
Check operation and condition of the wiper blades.
Check the flow of the washer spray.

7-25
Defroster Check
Move the control to the defrost symbol and the fan to
HI or the high symbol. Then check the airflow from the
ducts at the inside base of the windshield.
Mirrors and Sun Visors Check
Check that friction joints hold mirrors and sun visors
in place.
Seat Adjuster Check
When adjusting a manual seat, be sure seat adjusters
latch by attempting to move the seat after latching.
Lamps Check
Check panel lighting, warning lights, indicator lights
and interior lamps. On the outside, check: license plate
lamps, sidemarker lamps, reflectors or lights on outside
mirrors, headlamps, parking lamps, identification and
clearance lamps, taillamps, brake lamps, turn signals,
backup lamps and hazard warning flashers. Have
headlamp aim checked at once if beams seem
improperly aimed.Glass, Mirrors, Lamps and/or Reflectors
Condition Check
Look for broken, scratched, dirty or damaged glass,
mirrors, lamps or reflectors that could reduce the view
or visibility or cause injury. Replace, clean or repair
promptly.
Door Latches Check
Check that doors close, latch and lock tightly. Check for
broken, damaged or missing parts that might prevent
tight latching.
Hood Latches Check
Check that the hood closes firmly. Check for broken,
damaged, loose or missing parts that might prevent tight
latching. Make sure the secondary latch (if equipped)
keeps the hood from opening all the way when the
primary latch is released.