Lol. IMO I'd verify that it's actually the master cylinder that's leaking. Like I posted before, its pretty simple to confirm. Just remove the two nuts that secure the MC to the brake booster. You will see a rubber grommet and the brake booster pushrod sticking out. I'd say if you find brake fluid there it's indeed the master cylinder leaking. But that also means that all the fluid in the reservoir has gone into the brake booster, plus how ever much you've added along the way to keep it topped off. Another check you can do is to remove that vacuum check valve from the booster and stick something like a pipe cleaner (make sure it's not sharp at the end) down inside the brake booster, and if it comes up damp then I'd try to remove e the fluid somehow, especially if it's a lot. There shouldn't be any type of moisture in there. But on the plus side, if you find that the booster gives out later down the road, it's a pretty easy part to replace, if you plan ahead and find a way to support the master cylinder, you don't even have to mess with the brake system. Two nuts on the front, and four on the back. If it's possible, take the master cylinder in with you to match it up with a replacement. There are a few different ones that look somewhat similar. Or as in my case, the new one I got is completely different in shape and size, but is the correct one for my application.
Also like I mentioned before, now would be a good time to replace the rubber brake lines, since your gonna have to bleed the entire system anyways. Any signs of cracking, soft or hard spots in the rubber line is grounds for replacement.
Make sure you don't do as I did and not buy enough brake fluid. I bought a quart which is approx. How much the system holds, but the fluid coming out of the bleeders was nasty stuff. And I needed another quart and then some in order to flush the lines until clear new fluid came out and to top of the master cylinder.
I hate bleeding brakes...lol.
Don't forget to hold in the prop valve "centering pin" on the end of the valve. It's located under a little round rubber boot at the front end of the prop valve.
You must keep the pin depressed while bleeding the brake system or your brake system warning light will turn on inside the dash cluster, and they can be a little tricky to recenter. This is all assuming your gonna under take the task yourself. If your gonna have a shop do it, by all means, let them have at it!
