1997 GMC Suburban Owner's Manual - Page 398

100,000 Miles (166 000 km) (Continued) - 150,000 Miles (240 000 km) 0Drain?flush and refill cooling system (or every 60 months since last service, whichever occurs first). See "Engine Coolant" in the Index for what to use. Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure testthe cooling system and pressure cap. An Emission Control Service. - In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police or delivery service. these VJYIU rmt use your vehicle urder c l n ~ of do ' conditions, the.fluici crndfilterdo n.ot require chcrnging. Inspect Positive Crankcase Ventilation (PCV) valve. An Emission Control Service. DATE SERVICED ACTUAL MILEAGE BY DATE ACTUAL MILEAGE SERVICED B Y