[Threadkiller]

& 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.

 

[skinthead]

Somehow you are getting air in there with the lid off. How, well, that is indeed the question. Possibly no pressurefrom the inside keeping the piston seal from rolling when uncapped. Beats me, but that is about the only thing I can come up with after the some hundreds of thousands of bleeds I have done.

 

[Tony the torch]

remove the brake line and pump it a couple of times with your finger over the end.

 

[fatass]

Bench bleed?