Another Brake Bleeding Thread (lbs)

So I employed the help of my wife bleeding my rear brakes so that I could get the left center bleed valve on the front caliper.  Unfortunately after bleeding the servo PCV with the inverted front left caliper and then bleeding the front left center bleeder I am still hearing a high-pitched whining sound upon hard actuation of the rear pedal.

Something else I noticed, the second master cylinder is quite firm now and does not depress.  I seem to recall that prior to this drain and refill, I could easily actuate the second master cylinder by just putting sufficient pressure on the front left cylinder with my hand.  I recall seeing the rubber bushing get pushed in a good bit, but not all the way, and now that is not really possible.  The way I bleed the front left center bleeder valve was to have my wife pump the rear pedal and maintain pressure while I opened the bleed valve and then closed it before she released the pedal.  I am curious if somehow I pushed the second master cylinder out of its channel by pushing on the pedal after the caliper was removed from the fork and inverted.  If I can't get this figured out I think I'll have to disassemble the second master cylinder to check that it is actuating correctly and then refill and bleed the system again.

Anyone ever taken apart their second master cylinder on the front left brake caliper?

So I was able to unstick my second master cylinder after disconnecting and reconnecting the inlet line.  I realized that I believe the problem occurred when I was pumping the rear brake pedal while the caliper was hoisted up to get the correct orientation of the second master cylinder.  Anyway, that solved I commenced bleeding the servo PCV again and realized that if I pump the second master cylinder by hand it seems to help along the bleeding process by acting as a pump.  Now the only problem is that I either have an inordinate amount of air stuck in that circuit of the hydraulic system or I am doing something wrong.  I am guessing it is the former since I have only refilled the reservoir about three or four times now.  I suppose after about twice that amount of fluid passes through the system without air coming out of the line I should be okay.  Also, I realized that the servo PCV bleeder valve has an o-ring on it so I don't see how I could be pulling in air through the threads.  I am not sure if the caliper bleeder valves have o-rings, but I do suspect that I am pulling air through those threads when using the vacuum tool.   Anyway, I believe I am at least understanding the problem a little better now.  The good part is that I can reuse the fluid I am pumping through the system since the old fluid is long since flushed out.  I suppose I keep updating in the unfortunate case that someone else with LBS decides to drain and then refill their hydraulic lines.