GMC 2003 GMT560 T-Series, Owner'S Manual

Page: 244 / 284

❑
Wheel bearing (grease type) service (or every 24
months, whichever occurs first, and whenever
hubs are removed.)
(23) (46)
❑
Inspect door hinge pins and bushings and replace as
necessary.
❑
Steering system service. (13)
❑
Front and rear suspension service. (14)
❑
Spring-to-axle U-bolts and shackle bolts service. (16)
❑
Exhaust system service (or every 6 months,
whichever occurs first).
(3) (4) (17)
❑
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)
❑
Thermostatically controlled engine cooling fan
service.
(4) (20)
❑
Shields and underhood insulation service. (4) (5) (21)
❑
Rear axle air shift motor service.
(11)
❑
Air intake system service (or every 24 months,
whichever occurs first).
(4) (5) (24)
50,000 Miles (80 000 km)
❑
Change engine oil and filter (or every 12 months,
whichever occurs first).
(2) (3)
❑
Inspect air compressor discharge port (or every 6
months or every 1,800 hours, whichever occurs
first.)
6-10