GMC T-Series 1999 Owner's Manual page 304

Scheduled Maintenance (DURAMAX
78,000 Miles (124 800 km) (Continued)
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- - -
Spring to axle U bolts and shackle bolts service. (16)
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Exhaust system service (or every month, whichever
occurs first). (3)(4)(17)
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Air brake service (or every 6 months, whichever
occurs first). (39)
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Wheel bearing service (or every 24 months, whichever
occurs first, and whenever hubs are removed). (23)
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Wheels and tires service. (15)
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Hydraulic brake service (or every 6 months,
whichever occurs first). (7)
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Hydraulic brake caliper service (or every 6 months,
whichever occurs first). (22)
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Hydraulic parking brake service (or every 6 months,
whichever occurs first). (8)
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Engine drive belts service (or every 6 months,
whichever occurs first). (18)
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Clutch pedal free travel service. (10)
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Lubricate clutch shift block (or every month,
whichever occurs first).
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Throttle linkage service. (19)
7-42
t
DIESEL)
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Thermostatically controlled engine cooling fan
service. (4)(20)
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Shields and undercab insulation service (or every
month, whichever occurs first). (4)(5)(21)
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Air intake system service (or every 24 months,
whichever occurs first). (4)(5)(24)
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Replace fuel filter (or every 6 months, whichever
occurs first). (3)
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Fuel tank, fuel cap and fuel lines service (or every
72 months, whichever occurs first). (3)(30)
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Air cleaner filter replacement service (or every
24 months, whichever occurs first). (3)(4)(27)
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Rear axle air shift motor service. (11)
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Check air brake relay valve operation and check for
leaks (or every month, or every 300 hours,
whichever occurs first).
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Clean air brake application valve (or every 3 months,
or every 300 hours, whichever occurs first);
lubricate linkage.
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Air brake chamber service (or every 2 months,
whichever occurs first). (41)
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