1994 GMC Suburban Owner's Manual - Page 348

DIESEL ENGINES- MAINTENANCE SCHEDULElj- Tire Inspection* 23 Rotation** and Wheel t e 24 t + + + 25 BrakeSystemsInspection** Change filter every 15,000 miles (24 000 km), except when operating in dusty conditions. Dusty conditions may require more frequent filter replacement. Extreme dust and dirt operating conditions(off-road), may require the air filter to be checkedas often as every 300 miles (483km) and replacedas necessary. * An Emission Control Service ** See "Explanation of Scheduled Maintenance Services" in this section. A A Noise Emission Control Service H Applicable only to vehicles sold in the United States t This maintenance scheduleapplies to all diesel engines available. 10408/T0908 7- 14