1998 Chevrolet Astro Owner's Manual - Page 283

'Wait at least 30 minutes before checking the transmission fluid level if you have been driving: When outside temperatures are above 90°F (32°C). At high speed for quite awhile. 0 Checking Transmission Fluid Cold A cold check is made after the vehicle has been sitting for eight hours or more with the engine off and is used only as a reference. Let the engine at idle for five run minutes if outside temperaturesare 50°F (10°C) or more. If it's colder than 50°F ( 10°C), you may have to idle the enginelonger. Should the fluid level be low during a cold check, you must perform a hotcheck before addingfluid. This will give you a more accurate reading of the fluid level. In heavy traffic -- especially in hot weather. While pulling a trailer. 0 I To get theright reading, thefluid should beat normal operating temperature,which is 180°F to 200°F 182°C to 93 " C). See "Checking Transmission Fluid 'Hot" in the Index. Checking Transmission Fluid Hot Get the vehicle warmed up by driving about 15 miles (24 km) when outside temperaturesare above 50°F (10°C). If it's colder than 50°F (lO"C), drive the vehicle in DRIVE (D) until the engine temperature gage moves and then remainssteady for 10 minutes. Then follow thehot check procedures. Checking the Fluid Hot Cold or Park your vehicle on a level place. Keep the engine running. With the parking brake applied, place the shift lever in PARK (P) . With your foot on the brake pedal, move the shift lever through each gear range, pausing for about three seconds in each range. Then, position the shift lever inPARK (P). 0 Let the engine run at idle for three minutes or more. 6-21