Ok. I drilled through my master cylinder (don't ask). I installed a new one tonight. I managed to do it all without removing any other hardware. I got the new one in and as soon as I filled the reservoir with fluid, it leaked out around the plunger in my interior. I had to really screw around with the master cylinder to get it in, but I didn't force anything. Can allowing the plunger to move around and side to side cause some seal or something to rupture, or should that not really be a problem? Before I potentially ruin a 2nd one, I'd like to be sure, but I also don't want to spend all night pulling that brake booster out if it's not necessary.

I pulled the rubber cover off of my junk master cylinder and had a look around. It looks like there's a yellow plastic piece and behind that is the ball on the end of the plunger. I'm guessing that that piece pushes some sort of sealed piston which has the fluid in it, so even if I'm putting a little force on the plunger, it shouldn't cause anything to rupture.... right?

 

Damn. I meant to post this in the transmission forum. Sorry.