Hi, stumbled across this post whilst searching for the date Dataref for the toliss A321!
I know this is an old post, and I'm sure you have this sorted now, but in case anyone else Googles this, finds this thread and needs the info, here it is:
"AirbusFBW/TotLeftBrake", "FLOAT",
"AirbusFBW/TotRightBrake", "FLOAT",
"AirbusFBW/BrakeAccu", "FLOAT"
Hope this helps someone
Cheers