1997 Chevrolet Tahoe Owner's Manual - Page 395

100,000 Miles ( I 66 000 km) (Continued) In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. - 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 use. to Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test the cooling system and pressure cap. An Emission Control Service. Ifyou do not use your vehicle under any of these conditions, the fluid andfilter do require changing. not Inspect Positive Crankcase Ventilation (PCV) valve. An Emission Control Service. DATE ACTUAL MILEAGE SERVICED B Y DATE SERVICED ACTUAL MILEAGE BY