Chevrolet kodiak 2004 Owner's Manual page 317

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)
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