How to check and add fluid to your automatic transmission, Edit article how to check and add fluid to your automatic transmission. edited by carolyn barratt, farvand, maluniu, keywil and 3 others. your car's automatic. How to check transmission and discover possible, First, check the transmission fluid level and condition. if you don't know how to do it, here is an illustration: how to check the automatic fluid. Video: how to check transmission fluid levels, Transcript: how to check transmission fluid levels hi, i'm matt ediger from downforce motoring for about.com, and this is how to check your car's automatic.