These problems aren't new. About 20 years ago I was driving my car to work (HK Holden) & the brakes suddenly failed completely. I would normally fix it myself as a quick check showed it was a failed master cylinder. As I had to go to work I dropped it at the nearest mechanics & asked him to find out what the problem was & fix it. When I went to pick it up, he said it was the master cylinder & he had replaced it with a new one. Great, I thought. Until I drove it. I had to pump the pedal up to get any brakes & even then they would lock up. I managed to get it home & tried to bleed the brakes myself. After no success, I pulled the cylinder off & took it down to the local parts dealer. He checked the serial numbers & I found out the mechanic had fitted a master cylinder for a drum brake front. Of course, mine had discs. What annoyed me wasn't that he made an honest mistake. It was that he must have known how dangerous the car was when he gave it back & he charged me for his stuff up.