So, there's been some good responses and educational information...but, is there a problem or issue with the new MC not having the "extra hole" that my original has... and, what is that "extra hole" there for..?
I’d use it and not worry about it as long as it bench bleeds ok.
As for the old one, beats me. Could have been an error, cold be there’s a difference in the piston, seals or passages between the old and new one. As long as the new one works I wouldn’t give it a lot of though unless you want to tear them down and compare the internals.
