My FF Roadster (Coyote, TKO600, Hydraulic Clutch from Forte) has been on the road for about 5200 miles over the last 4 years. It's been bullet proof and not given me a problem EXCEPT I've been having a weird issue with my clutch. The problem only seems to come on when I'm driving in stop and go traffic, or it's warm outside. As the car heats up, the clutch stops working, to the point where even with the clutch depressed all the way the car is still pulling. Essentially the clutch isn't engaging. If I shut the car off for awhile, the car cools, and the clutch works fine. Now, in my mind this tells me that the hydraulic fluid must have air in it and the bubbles are heating up and causing an issue. So, I rebled the clutch a couple of times but the problem did not resolve. I had someone much more experienced then I bleed the clutch to their point of satisfaction and the problem did not go away. (BTW, there is no leak in clutch fluid at any point in the system. No leaks and no drop in fluid levels over months).

My next step was to pull the slave cylinder and adjust the bar (Threaded rod) within the cylinder to better engage the clutch when depressed. This worked.... for awhile, and then after a couple of weeks the problem would come back. I figured that the nuts controlling the length of the bar (sorry I don't know the proper name of this bar) must have vibrated and somehow the bar shortened itself. So I put locktight on the nuts, and the issue still happened. So I welded the nuts and the issue still came back. Finally, I cut a longer bar (threaded rod) and welded the nuts so that there was more rod to engage the clutch, and it seemed to have solved the problem... for about 500 miles. Tonight (a nice cool fall night) I was out for a drive and the issue appeared again. Sitting at a light, in traffic, I had to shut off the car as it was pulling strongly enough that I was spinning the rear tires with the brakes depressed. Additionally, in first gear I could let off the gas completely and leave the clutch out and it would not stall out. At this point I couldn't easily shift out of gear, or back into gear (Again the clutch wasn't fully engaging). I pulled over and parked for about an hour. Started the car up and drove about 20 miles home and it worked as perfectly as can be. Shifted beautifully.

So my assumption is that my lengthening of the bar within the slave cylinder on the hydraulic clutch set up from Forte was a bandaid fix that engaged the clutch better... for awhile, and then when it heated up enough, the problem returns.

I would so appreciate any thoughts on where to start looking at what the problem might be. I've had people tell me that the master cylinder must be leaking air in, causing bubbles when the fluid heats and thus making the clutch not engage enough. I've had others tell me to put a longer "threaded bar" in the slave cylinder since it worked before, but again, adjusting that seems like a bandaid. I want it fixed properly because it's scary as hell to find that you can't take the car out of gear and it just wants to go...

Any thoughts, or anyone who has experienced something similar? I'm all ears at this point. Thanks in advance