Kendall, I am overdue for a change with your cooler. Please, a quick refresher for quantity and refill point. Thank you Sir
With the Cool Tech (Setrab) cooler, the cooler fills from the bottom and return to the transaxle is from the top of the cooler.
On your 3-year change intervals there are two methods.
1. You can drain the transaxle "normally" and fill "normally". You should measure the fluid you get out. In a car that has been started/driven recently, you will drain out 3.9-4.0 quarts, and this it what you will be able to add back through the fill plug. In this scenario, you will still have "old" oil in the cooler and lines.
2. For a complete change, you should also drain the cooler which can be accomplished by removing the bottom line to the cooler. Most likely, you will need to temporarily un-bolt and lift the cooler so that you can access the bottom line.
The cooler will hold about .65 quarts.
OEM: 4.0 quarts capacity (although you always seem to only get out ~3.8 quarts)
OEM + Cool Tech Cooler = 4.8 quarts (20% added fluid capacity)