Must be something in this Fall air, my master cylinder just failed on my 69 Road Runner a few weeks ago. Mine is a manual brake set up though.

Hope your failure wasn't as interesting as mine, I lost all brakes and took a little trip around the side on my garage, through some gravel, over my man door walkway, through my back yard and got it slowed down enough to slam it in park. Didn't hit or touch anything though. Could have been much worse.

Bench bled the new master last weekend, threw it on the car and bled the brakes, good to go now.