Have you ever depressed your clutch pedal, only to hear a "pop", the pedal goes straight to the floor, then see a funny black round part at your feet that looks like this? Well, this happened to my daughter a few weeks ago. I had no idea what this part is but she found the answer. It's the stock clutch master cylinder rod end that, with time, deteriorates and eventually breaks off. According to Ford, this part is not available separately and you must purchase a complete master cylinder! She did research and found this: Not only did I get one for her, but for myself too. I think before this part breaks without warning and leaves you stranded, replace it with an aftermarket aluminum piece like this one.