1998 GMC Safari Owner's Manual - Page 374

Long Tripmighway Maintenance Schedule 100,000 Miles (166 000 km) 0 Inspect spark plug wires. I DATE MILEAGE An Emission ControlService. 0 Replace spark plugs. An Emission ControlService. c7 If you haven't used your vehicle under severe service conditions listed previously and, therefore, haven't changed your automatic transmission fluid, change both the fluid and filter. 17 Inspect Positive Crankcase Ventilation(PCV) valve. An Emission ControlService. 150,000 Miles (240 000 km) 0 Drain, flush and refill cooling system (or every months since last service, 60 DATE I whichever occurs first). See "Engine Coolant" in the Indexwhat to use. for Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test the cooling system and pressure cap. An Emission Control Service. 7-40