GMC 2010 T-Series Owner's Manual page 251

1 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 the condition of cooling and
heater hoses and clamps. Replace hoses if
cracked, swollen, or damaged.
1 Wheels and tires service. (13)
1 Hydraulic brake service (or every 6 months,
whichever occurs first). (6) (30)
1 Parking brake service (or every 6 months,
whichever occurs first). (7)
1 Air brake service (or every 6 months, whichever
occurs first). (26)
1 Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first). (27)
1 Check air brake relay valve operation and check
for leaks (or every month, or every 300 hours,
whichever occurs first).
1 Clean air brake application valve (or every
3 months, or every 300 hours, whichever occurs
first). Lubricate linkage.
1 Air brake chamber service (or every 2 months,
whichever occurs first). (28)
1 Air brake system valve service (or every 3 months,
or every 900 hours, whichever occurs first). (31)
1 Rear axle air shift motor service. (9)
1 Air intake system service (or every 24 months,
whichever occurs first). (3) (4) (20)
115 000 km (72,000 Miles)
1 Lubricate U-joints (or every 6 months, whichever
occurs first).
120 000 km (75,000 Miles)
1 Vehicles Without Engine Oil Life System Only:
Change engine oil and filter (or every 12 months,
or every 750 hours of engine operation, whichever
occurs first). (2) (33)
1 Vehicles With Engine Oil Life System Only: Check
oil life system (or every 12 months, or every
750 hours of engine operation, whichever occurs
first). If engine oil and filter are changed, reset
system. See Engine Oil Life System on
page 5 19. (2) (8)
1 Inspect engine air cleaner filter change indicator.
If necessary, replace the filter. If vehicle is driven
in dusty/dirty conditions, inspect filter change
indicator at every engine oil change. See Engine
Air Cleaner/Filter on page 5 21 for more
information.
1 Chassis lubrication service (or every 6 months,
whichever occurs first). (10)
6-13