My adventure in braking wasn't as bad by any stretch, but it still got my attention.
The day I went to pick up 'Tater I checked it out, got the brakes functional, altho I had to remember NOT to retract the pedal all the way as the hydrovac was dead so it was relying on the residual pressure to keep it stoppable and the pedal didn't like to come back on it's own.
We got a fair ways down te road, tested the brakes & everything, and before I pased through the 1st town we pulled over so I could do a walk around and add some gas. when we got rolling again it was dragging on the brakes a bit, and without thinbking I pulled the pedal all the way up,...
So, I'm comin up to a major intersection, have a red light, and as I shift down I pressed the brakes, and they went to the floor and stayed there.

Thankfully I was suck in low gear, managed to slam it into 2nd and by some miracle the right turn lane was open so I managed to swing it onto the shoulder without entering traffic and ramming the busload of kids that were in the intersection. The shaft brake worked real well considering it was pretty shot, may have been my pucker factor 12 helpin out tho. I pumped the brakes back up, limped her to a service station up the road, and called a tow.
It was my fault, I knew what not to do and I expereinced a bit of mental flatuence to go with my case of cranial rectumitis. One of the 1st systems that got a rebuild was the brakes. 90% new parts, the rest were rebuilt or deemed servicable. The old girl will stop in nothin flat, even with a load, thereby preventing me from carying my own load in my shorts.