Woz1976-MT
New member
2) why pull the drain plug if you are draining it through the cooler lines?
If you want to be extremely OCD, you need to completely drain the pan first before you start the cooler line method, otherwise as you are adding a couple of quarts to the pan it will be mixing with old fluid still in the pan. Granted you could always use 16-18 quarts during the exchange and it would be negligible about how much original fluid was still in the whole system, but some of us tend to be a bit more OCD.
If you are measuring very carefully (and you're certain your A/T fluid was at the proper level before beginning), you don't need to mess with the fill bolt on the side of the transmission. Keep in mind that when you put everything back together and do the fluid level check and you don't get any fluid running out, you either have to disconnect the cooler lines to add fluid or use the fill bolt.
I would say try it your way, but just be fully prepared to remove the fill bolt just in case. It never hurts to be prepared for any contingencies.