DON'TIm trying to get my pistons off to clean
Seriously.
You got air into it!
Now you have to perform a procedure called "bleeding" to get the air bubbles out and the brake fluid in.
I've bled my brakes before but this time it seems like the fluid isn't even leaving the reservoir. If I pull on the brake I see very very small bubbles. Do I just have to keep doing that untill there's pressure and I can bleed the rest?