I don't think my master needs a rebuild as it was working fine before I tore the calipers apart. My bike's a 2011 with 43k miles. It is a very long system, I'm aware, I just don't know what to do to completely flush the system. I think I'll buy some more brake fluid tomorrow and do a non stop flush for about 15 minutes, see if I get anything.
I tried hanging the calipers sideways today to see if I can get any air out that might've been stuck inside the caliper, I got nothing, going to leave it hanging upside down overnight, with the lever pulled, see if it's better by morning.
It does have the stock lever. Why?
There's no bleed nipples by the abs unit right? That would've helped as I could scratch it off the list. Of course the ABS unit having upward facing hoses doesn't help the situation, some chance I got a bubble in the stupid ABS unit as it's a high point.