Avensis T27 EPB / Emergency release

[AvensisTJB]

Hi, my sons Avensis started popping  up the EPB warning lights. We could see  & hear the brake accutator moving and the lever arm on the brakes. It worked ok then would intermittently pop up a warning. We read on a web page that if you do the emergency release then apply brkaes/drive fopr a short while it may recalibrate. After incorrectly turning the Hex key anti clock wise , we turned it clock wise, and it seems full disengaged (car rolls when pushed). But now when we try and apply the EPB we hear the acctuator motor try and run  but only for about 3 - 5 secs.  .. Have tried holding the EPB button doen for 5 to 8 secs but and it whirs but then pops up a EOB overheat warning.. Help.. how do we get it back working..Thanks