GMC 2010 T-Series Owner's Manual page 245

1 Thermostatically controlled engine cooling fan
service. (3) (17)
1 Shields and underhood insulation
service. (3) (4) (18)
36 000 km (22,500 Miles)
1 Check fluid levels (or every 3 months, whichever
occurs first). (1) (5)
1 Chassis lubrication service (or every 6 months,
whichever occurs first). (10)
1 Inspect door hinge pins and bushings and replace
as necessary.
1 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 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 Air intake system service (or every 24 months,
whichever occurs first). (3) (4) (20)
1 Rear axle air shift motor service. (9)
40 000 km (24,000 Miles)
1 Lubricate U-joints (or every 6 months, whichever
occurs first).
6-7