I have tried searching for this issue all over the internet, but have not found anything related to it, so I am hoping that someone here may have had this issue already and has found a viable solution. I will try to be as brief as possible.
A little over a year ago, my clutch pedal went to the floor and stayed there. My son is a mechanic and worked at a local transmission shop at the time. He told me it could be the master cylinder, the slave cylinder, or the clutch, or even a combination of those things. I went ahead and got all three parts from Auto Zone (Duralast brand), and he replaced the slave cylinder and clutch for me. The reason he didn’t replace the master cylinder at that point was because dropping the trans and replacing what he did took way more time than he thought, so he delayed the master cylinder, since the clutch was working OK. He did suggest that the master cylinder still should be replaces, and did that about a month later. This was in October of last year. Everything was fine until June of this year. At random times, the master cylinder would seize up, and I was not able to push the clutch pedal more than halfway. Since the part was still under warranty, we swapped it out for another one, and that seemed to do the trick for about a month. Then that one started seizing up as well! We were both baffled, and I finally decided to talk to a mechanic friend at our church, and he suggested replacing the master cylinder with a dealer part instead of the Duralast one. He did that, and when I went to pick up the car, I noticed that the clutch pedal was sitting a few inches higher than normal. Both my mechanic friend and my son said the same thing: maybe the rod on the dealer part is a little longer than the Duralast one. Didn’t make much sense to me, but I figured they knew what they were talking about, so thought I would just have to get used to the new clutch pedal position. Three days later, I go to start the car, and the clutch pedal went to the floor and stayed there!!!! Since it was the first day of my new job, I didn’t have time to mess with it, so I rented a car for the week, and had my son come over that weekend to take a look. I assumed that the system needed to be bled again, so that is what we tried to do. However, when we weren’t getting any pressure with me manually pumping the clutch pedal with my hand, my son got under the dash and saw that the linkage was not connected! He popped it back on, and not only was it working again, but the clutch pedal was back to its original position!!! Over the next several weeks, the linkage would pop off ever 3-4 days, and I would just pop it back on. Once it started happening every day, I contacted my mechanic friend, and he agreed to replace the master cylinder, since it was still under warranty. He confirmed that the clip that connects to the clutch pedal was broken, and assured me that the new master cylinder was just fine. I picked up the car this past Saturday, and when I got in, the clutch pedal was sitting higher again! Since it was raining real bad, I decided to just get the car home and get under the dash the next day and see what was going on. So, yesterday I get in and try to start it so I can pull it into the garage, and the clutch pedal went to the floor and stayed there!!!! A quick check confirmed that the linkage popped off again!!!! I reconnected it, and it was fine. Well, sort of. As with the last one, I noticed that once it was reconnected, and I would start to pump the clutch pedal, I could actually see the connector slowly walking its way off the clutch pedal!! I believe it is supposed to snap on and stay in place, but something is causing it to walk off the pedal and disconnect!!!! I am at my wits end trying to figure this issue out!!! Is there anyone out there that has had this issue????
By the way, my car is a 2002 Chevy Cavalier LS Sport, 2.2 Ecotech with 5-speed manual.
Any help, suggestions, or ideas would be greatly appreciated!!!!

I haven’t had an issue with the connector walking off the post on the pedal but I have split the plastic connector on the master. My fix was to remove the master and pedal, remove the plastic connector, use a die to thread the rod on the master, and install a studded rod end from McMaster Carr. Pedal needed to be removed to cut the post off the pedal and drill a hole for the stud to utilize.

I’ll warn you install is a bit of a bitch as there isn’t much room to get the stud into the pedal but I haven’t had any issues since and it actually gives the clutch pedal a bit more positive feel.