For the brake genius out there.

[Cuppa]

G`day All
Cuppa to answer your question, it`s exactly what we want, that is for the cups to move out then when they return the agitation of the fluid drags the little air that is left in the cyl, out.

That makes sense, allowing max movement of the cups. I can imagine in that scenario the 'timing' of opening the bleed nipple might be super critical, more so than in 'normal' bleeding procedure.