GMC 2003 C4C042, Owner'S Manual

Page: 355 / 386

7-9
j Wheel bearing (grease type) service (or every
24 months, whichever occurs first, and whenever
hubs are removed). (23)(46)
j Inspect door hinge pins and bushings and replace
as necessary.
j Steering system service. (13)
j Front and rear suspension service. (14)
j Spring
-
to
-
axle U
-
bolts and shackle
bolts service. (16)
j Exhaust system service (or every 6 months,
whichever occurs first). (3)(4)(17)
j Wheels and tires service. (15)
j Hydraulic brake service (or every 6 months,
whichever occurs first). (7)(46)
j Parking brake service (or every 6 months, whichever
occurs first). (8)
j Thermostatically controlled engine cooling fan
service. (4)(20)
j Shields and underhood insulation service. (4)(5)(21)
j Rear axle air shift motor service. (11)
j Air intake system service (or every 24 months,
whichever occurs first). (4)(5)(24)
j Evaporative Control System service (if equipped) (or
every 24 months, whichever occurs first). (3)(26)
[
j Air brake service (or every 6 months, whichever
occurs first). (39)
j Air brake automatic slack adjuster service
(or every 500 hours, whichever occurs first). (40)
j Check air brake relay valve operation and check for
leaks (or every month, or every 300 hours,
whichever occurs first).
j Clean air brake application valve (or every 3 months,
or every 300 hours, whichever occurs first); lubricate
linkage.
j Air brake chamber service (or every 2 months,
whichever occurs first). (41)
j Trailer brake hand control valve service (or every
3 months, or every 900 hours, whichever
occurs first). (42)
j L18/LB7 Engines Only: Clutch pedal free
travel service. (10)
50,000 Miles (80 000 km)
j DURAMAXt Diesel Only: Change engine oil
and filter (or every 12 months, whichever occurs
first). (2)(3)
j Inspect air compressor discharge port (or every
6 months or every 1,800 hours, whichever
occurs first).