Brake pedal sits too low

Guys... I... I think I've found the answer to all of the problems that I've been having...

So the little rubber washer/bushing that goes into the groove on the pushrod?
Well, there wasn't one on the vehicle when I pulled the old MC out, so when I pulled the new MC out of the box, I had no idea what it was for... and now I can't find it. How screwed am I?