keep in mind "bleed down" on fluid pressure, differs from "air ingress'. and should be treated accordingly.. they are completely different, and come from differing issues.. 'member how I mentioned that air ain't coming in thru the master cylinder?, on another issue..? loss of pumping pressure can come from damaged seals, but as there is no "air" issue, it's just loss of "first pump" compression on fluid. Seal replacement is the cure.
Yes, there's a chance the calipers are faulty still for one reason or another. That's why I have used calipers sitting in the garage, in case the master rebuild doesn't fix it.
At this point, first pump pressure is lost only after riding the bike, which I think is very weird.. It might be because the pistons actually move back and forth and calipers might be leaking as the pistons come in and go out.. They work fine while on the bike, seem to have constant pressure. But once I'm home and I put the ziptie on, 2 hours later, lever feels empty
I don't know at this point. I just want to ride my bike reliably again