Install new master cylinder without bleeding?

swingingdart said
If its fuller than that will it want to leak out?

Tooljunkie said
Some leak, some dont. Where the rubber sits on master,if the casting is machine finish smooth, it shouldnt leak.

I take the master cylinder apart and flat file the cap sealing surface until it’s smooth.
Then flush it out and reassemble.
It’s worth it to not have it seep all over the master.