1994 Chevrolet Astro Owner's Manual - Page 238

If you have the 4.3L engine (VIN Code W) with the square air cleaner,you can change the air cleaner filter without removingthe engine cover. Just lift the hood, unsnap both clips and removethe top. After changing the filter, snap both clips to secure the air cleaner. Besure air cleaner lid is correctly positioned to seal out dust and contaminants that are harmful to your engine. Refer to the Maintenance Schedule to determine when to replacethe air filter. See "Scheduled Maintenance Services" in the Index. NOTICE: If the air cleaner off, a backfire can cause damaging engine is a fire. And, dirt can easily get into your engine, which will damage it. Always have the air cleaner in place when you're driving. Automatic Transmission Fluid When to Check and Change A good time to check your automatic transmission fluid level is whenthe engine oil ischanged. Refer to the Maintenance Schedule to determine when to change your fluid. See "Scheduled MaintenanceServices" in the Index. How to Check Because this operation can be a little difficult, you may choose to have this done at a GM dealership Service Department. If you do it yourself, be sure to follow all the instructions here, or you could get a falsereading on the dipstick. 6-20