1997 Buick Skylark Owner's Manual - Page 324

I Short Trip/City Maintenance Schedule In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. I f you do not useyour vehicle under any of these do conditions, thefluid andfilter not require changing. I 150,000 Miles (240 000 km) 0Drain, flush and refill cooling system (or every 60 months sincelast service, whichever occursfirst). See "Engine Coolant" in the Index for what use. to Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test coolin system and pressure cap. An Emission Control Service. ACTUAL MILEAGE SERVICED BY: DATE SERVICED ACTUAL MILEAGE BY: I I 7-27