& I (we've) done it dozens or hundreds if times, so riddle me this. How can an uncapped master cylinder makes all kinds of air bubbles as if if had a HUGE air leak, with zero evidence of any leaks only to build monster lever pressure when firmly capped? All of the masters I have ever bled make pressure when capped or open, but this bitch makes zero pressure when exposed to atmosphere. Thoughts, ideas, suppositions please. TK.