1997 Chevrolet Blazer Owner's Manual - Page 269

A CAUTION: Operating the engine with the air cleanercan off cause you or others to burned. The air cleaner be air, if not only cleans the it stops flame the engine backfires. If it isn't there, and the engine backfires, you could be burned. Don't drive with it off, and be careful working on the engine with the air cleaneroff. Automatic Transmission Fluid When to Check and Change A good time to check your automatic transmission fluid level is when the engine oil is changed. Change both the fluid and filter every 50,000 miles (53 000 km) if the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. NOTICE: Uses such as found in taxi. police or delivery service. If you do not use your vehicle under any of these If the air cleaner off, a backfire can causea is conditions, the fluid and filter do not require changing. damaging engine fire. And, dirt can easily get See "Scheduled Maintenance Services" in the Index. into your engine, which damage it. Always will have the air cleaner in place when you're driving. 6-14