ok so if the slaves come pre-bled, and u bench bleed the master, why would u still have to bleed it after its in the car??? seems as though u would be done.

 

Because it is unlikely you will get the two connected without a burp of air entering the system. Mostly full/ bleeding a burp is much easier than a total system fill on the car( why bench/ pre -fill is done)

 

but from what ive been ready ur only supposed to crack the bleed the close it again right away. how in the heck is that supposed to get the burp out. ud have to go thru all the fluid in the slave in hopes that there might be some air in there.