GMC T-Series 1999, Owner'S Manual, Page: 273 / 344

yellow blue
Scheduled Maintenance (Except DURAMAX
t
DIESEL)
7-11
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.
39,000 Miles (65 000 km)
j Engine oil and filter service. (3)(9)
j Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
j Clean air conditioner filter (or every month,
whichever occurs first). See “Air Conditioner Filter”
in the Index.
42,000 Miles (70 000 km)
j Engine oil and filter service. (3)(9)
j Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
j Chassis lubrication service (or every 6 months,
whichever occurs first). (12)
j Clean air conditioner filter (or every month,
whichever occurs first). See “Air Conditioner Filter”
in the Index.
j Lubricate door hinge pins and rollers with engine oil.
j Wheels and tires service. (15)
j Hydraulic brake service (or every 6 months,
whichever occurs first). (7)
j Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)
j Clutch pedal free travel service. (10)
45,000 Miles (75 000 km)
j Engine oil and filter service. (3)(9)
j Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
j Clean air conditioner filter (or every month,
whichever occurs first). See “Air Conditioner Filter”
in the Index.
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)