2007 Chevrolet Colorado Owner's Manual - Page 342

How to Add Automatic Transmission Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See Recommended Fluids and Lubricants on page 455. Add fluid only after checking the transmission fluid while it is hot. A cold check is used only as a reference. If the fluid level is low, add only enough of the proper fluid to bring the level up to the HOT area for a hot check. It does not take much fluid, generally less than one pint (0.5 L). Do not overfill. Notice: Use of the incorrect automatic transmission fluid may damage your vehicle, and the damages may not be covered by your warranty. Always use the automatic transmission fluid listed in Recommended Fluids and Lubricants on page 455. • After adding fluid, recheck the fluid level as described under "How to Check Automatic Transmission Fluid," earlier in this section. • When the correct fluid level is obtained, push the dipstick back in all the way; then flip the handle down to lock the dipstick in place. 342 Manual Transmission Fluid When to Check A good time to have it checked is when the engine oil is changed. However, the fluid in your manual transmission does not require changing. How to Check Because this operation can be a little difficult, you may choose to have this done at your GM dealership service department. If you do it yourself, be sure to follow all the instructions here, or you could get a false reading. Notice: Too much or too little fluid can damage your transmission. Too little fluid could cause the transmission to overheat. Be sure to get an accurate reading if you check your transmission fluid. Check the fluid level only when your engine is off, the vehicle is parked on a level place and the transmission is cool enough for you to rest your fingers on the transmission case.