Last time I looked they had about half a dozen of them left at mainline, running them on thin routes like YUL-FRA. All of them were 29-31 years old. From what I read, they were due to be replaced by A330 last fall but it seems the phase out is dragging on:
https://en.wikipedia.org/wiki/Air_Canada#Current_fleet
They can't find anything currently available that generates the bucket loads of money these paid off 333s and 763s generate. The MAX situation exarcebates this for AC as well.
Rouge (which is the same thing as AC regardless of what the marketing department says) has 25 of them with no replacement in sight.