GMC 2003 GMT560 T-Series, Owner'S Manual

Page: 241 / 284

22,500 Miles (36 000 km)
❑
Check fluid levels (or every 3 months, whichever
occurs first).
(1) (6)
❑
Chassis lubrication service (or every 6 months,
whichever occurs first).
(12)
❑
Inspect door hinge pins and bushings and replace as
necessary.
❑
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 condition of cooling and heater
hoses and clamps. Replace hoses if cracked,
swollen or damaged.
❑
Wheel bearing (grease type) service (or every
24 months, whichever occurs first, and whenever
hubs are removed).
(23) (46)
❑
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)
❑
Air intake system service (or every 24 months,
whichever occurs first).
(4) (5) (24)
❑
Rear axle air shift motor service. (11)
6-7