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?

 

Anybody know? I was hoping to get some responses before I put the 2nd one in tonight.

 

Yea it sounds like you broke the seal on the 1st new one. Pull the brake booster off for clearance and try not to stress the plunger arm any more than normal cluch operation would do.
Always a fun job especially bleeding the sucker after install.
Good Luck!
SSC

 

Pulling the booster off (and especially putting it back) is a sonofabitch and was really hoping that i didn't have to do it.

I know all about the pains of bleeding the system too. I've bled the IROC so many times that it was squirting clean fluid and my pedal still sucks.

 

"My pedle still sucks"

One little trick that worked for me before on a s10 was to pop the bleeder open and remove the resivor cover and let it sit over night and gravity bleed. I pumped that suker for an hour with no luck let it set overnight tightened it up in the morn tryed bleeding it again 2 bleeds later it was perfect.
If your not in need of the car this moment try it and see if it helps.
SSC

 

Good idea. Maybe I'll try that on my IROC.

Anyway, here's an update. I took a different approach when I installed this one. On the last one, I hooked the slave cylinder tube to the MC up where I could reach it, then had a bitch of a time putting it into place. This time, I put the MC into place first. It slid right into the hole on a straight-shot. No bending, twisting or tweaking necessary. I didn't have to touch the booster or steering column either. Anyway, once it was in place, I had to reach way down into the cramped area to install the tube and press the holding pin into place. It was a pain, but much better than removing the booster. After I got that on, I tightened the MC, put the SC back into place and bled it. Took a total of about 2 hours.