GMC TopKick 2007 Owner's Manual page 375

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)
C600, C700, and C800 Gasoline Engines Only:
Engine drive belts service (or every 12 months,
whichever occurs first). (17)
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).
67,500 Miles (108 000 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)
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.
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)
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