GMC TopKick 2007 Owner's Manual page 372

Air brake system valve service (or every
3 months, or every 900 hours, whichever
occurs first). (37)
Thermostatically controlled engine cooling
fan service. (3) (19)
Shields and underhood insulation
service. (3) (4) (20)
Rear axle air shift motor service. (10)
Air intake system service (or every 24 months,
whichever occurs first). (3) (4) (23)
Evaporative Control System service, if
equipped, (or every 24 months, whichever
occurs first). (2) (24) †
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).
372
48,000 Miles (75 000 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)
Lubricate U-joints (or every 6 months, whichever
occurs first).
50,000 Miles (80 000 km)
Inspect air compressor discharge port (or every
6 months or every 1,800 hours, whichever
occurs first.)