GMC T-Series 1999, Owner'S Manual

Page: 300 / 344

Scheduled Maintenance (DURAMAX
t
DIESEL)
yellow blue
7-38
52,000 Miles (83 200 km) (Continued)
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 900 hours, whichever occurs first). (42)
j Air brake automatic slack adjuster service (or every
500 hours, whichever occurs first). (40)
j Check starter brushes for wear (or every 12 months,
whichever occurs first). Replace as needed.
j Check generator brushes for wear (or every
12 months, whichever occurs first). Replace
as needed.
55,250 Miles (88 400 km)
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 Lubricate clutch shift block (or every month,
whichever occurs first).
58,500 Miles (93 600 km)
j Change engine oil and filters (or every 3 months,
whichever occurs first). (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 water pump (or every 3 months, whichever
occurs first).
j Lubricate steering column shaft (or every 3 months,
whichever occurs first).
j Inspect door hinge pins and bushings and replace as
necessary. Lubricate door hinge pins and rollers with
engine oil.
j Replace air conditioning filter dryer (or every
18 months, whichever occurs first, and whenever
refrigerant charge is lost for any reason).
j Wheels and tires service. (15)