Chevrolet kodiak 2004 Owner's Manual page 321

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)
Rear axle air shift motor service. (11)
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) †
50,000 Miles (80 000 km)
DURAMAX™ Diesel Only: Change engine oil
and filter (or every 12 months, whichever occurs
first). (2) (3)
Inspect air compressor discharge port (or every
6 months or every 1,800 hours, whichever occurs
first.)
52,500 Miles (84 000 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)
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