Install new master cylinder without bleeding?

Short answer is no, as soon as you remove the old one you will introduce Air into your lines.
So I will need to bleed all four wheels?
Nice. My cylinder has had the look of being wet for a while. I was told that is normal, now I noticed paint bubbling up below it on the firewall.:mad: So I think it's time for a new one! Just thought I'd throw it out there, i literally just got done bleeding them a few months ago. I dont have a helper, no I have to bribe the wife to come out and help. I'm under the car "hows the pedal feel?" Her: "um, I dont know! You come see!"......... So yep. Fun fun. Well thanks for the bad news! :)