So I guess my clutch power spring was never working ..

I have been systematically working on getting the cruise to work on my 03 C4S. I bought car last November with 56k on it I have put a thousand or so on it since I did Clutch, IMS etc. Clutch was definitely lighter post replacement but in no way could be described as light, I finally got around to removing clutch power spring which had been making bad noises for a while and is clearly broken as it fell apart as soon as I removed it. The spring itself cracked and is in multiple pieces. New one was an absolute bear to fit (canister is slightly larger diameter) and I am 6'2" and have huge hands and there is just no room to get into foot well. An hour of cursing later and I finally had it in. Clutch pedal is now feather light and has almost an over center feel to it as travel increases. It remains to be seen if I end up disliking the light assisted feel as some here have. I must say it really is very, very light now. David

Had the same experience, every time I drove it was leg day... Interestingly and luckily for you LHD folk you can get the canister in, on a RHD car you need to take the pedal assembly out...

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Well that makes it a whole different proposition. I should stop complaining. The original part is no longer available and the Porsche replacement has a larger 'canister' around the spring and in the end I had to loosen a 6 mm bolt that holds the support frame for spring pivot point. That allowed me to spread the frame that supports the pivot just enough to get the dang thing installed. I did think of quitting a couple of times. I just don't fit in that spot :-) You can see how the position of the pivot of the spring relative to the pivot of the pedal means, as others have said, the assistance does not not start immediately and does explain the 'over center' feel of the assistance. I am curious if it was poor spring steel or bad heat treating that caused that spring to fail. It has fractured in two spots and it does not look like a classic fatigue failure. Looks more like the steel had inclusions and the torque has just ripped it apart. Odd David

IMO the constant expansion and contraction of every pedal press and release over the years fatigued the spring and broke it

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Most logical explanation. Fracture of steel is almost like a spiral fracture in a bone. In other words it broke over the length of the spring and the actual fracture is 3-4 times longer than the diameter of the spring. This makes me think internal stress and hence as you say, most likely fatigue.

I took my spring out after it failed, which failure caused the clutch pedal to not travel back to its original position. My spring was "working" up until it failed I believe because it is much harder to engage the clutch now. It is also much easier to tell when the clutch is biting, and I am not stalling as much or burning the clutch as much. No plans to replace the spring, even though I bought it. Other guys have had success with replacing the spring with one from Home Depot. My cruise control has never worked, I guess that might be a symptom of the spring failing.

I lived with a non spring assisted and old clutch for 3 months and have used a non spring assisted new clutch (lighter but not light) for the last 5-8 months. While the force required was high it was not un-manageable. I have only driven with spring assist for literally 5 mins last night and it is very, very light. I will give it until the end of the year to make a fair comparison and just remove it if I have problems knowing exact point of engagement or I just can't live it. The 911 continues to be a voyage of discovery.....

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There seems to be an issue when fitting a replacement helper spring that changes the clutch pedal travel just enough to stop the cruise switch mounted near the pedal from working properly. I have a small rubber vacuum cap to fit on the switch plunger I believe will resolve the issue by extending the reach of the switch plunger. Hopefully, this will get my cruise working again like it was prior to replacing the original squeaky spring. TBD

See the famous old thread called "dramatically Improved my clutch action"!

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Thanks, I read all of the threads before I started work and had an idea their may be a big change.

I drove around a few times without the spring, I didn't like the side to side movement and loose feeling of the pedal. IMO you need a spring to prevent that movement either standard or DIY replacement.

Update: After a day or so of driving I am liking the softer feel and have no issue finding the bite point. The real benefit and and why I went down this route in the first place is Cruise Control seems to work every time now. The over center action of the spring at the very top of the travel 100% contacts clutch switch and I no longer have to pull pedal up with my toe. I also had issue of dirty multifunction switch contacts but some aerosol contact cleaner seems to have fixed that.