Hello, I have a 1999 A8 and cant find the plug to drain the fluid oil from the transmision torque converter. Do they have one or how do you flush all the fluid from transmission the pan only had like 5 litters and the whole transmiison uses about 12. Can you help me pls. Thank you

 

?????

 

Unfortunately, the trans has to be pulled to drain the TC...only a shop "flusher" (using WAY more ATF than the original capacity...$$) can truly do it on first try with trans installed...or multiple fillings (and driving cycles) the home method.

But you only have a total, on factory fill, of 9.8 liters of ATF...a simple drain won't release much more than 4-5 liters. With pan and filter off you'll drain out 7-8 liters, IF it was full in the first place.
If you do not remove the pan and change filter, you are not only wasting your time, you are likely doing more harm than good...new ATF (with fresh detergents) will likely break loose more sediment which will go directly to an already partially clogged filter. A clean unrestricted filter is truly more important than new ATF, to assure full pressure reaching all valves, clutches, etc...lubrication is just one purpose of ATF.