Why do we have a give a pressure 0 call out when checking brakes while taxi on the old A320s but not in the newer A320s.?
I found an answer here: https://www.pprune.org/tech-log/456530-a320-brake-check.html
The complete fly by wire braking system apparently eliminates the check for residual pressure (check zero) of the older models, probably because the valve that determines which hydraulic pressure reaches the brakes is either no longer present or automatically tested anyway.
The new a320 also has a different PTU design which no longer barks...