[Oldcarguy]

These might help:

http://986forum.com/forums/performance-technical-chat/74264-ideas-sticking-clutch-pedal-only-when-braking-heavily.html

http://986forum.com/forums/boxster-general-discussions/72861-found-spring-drivers-side-footwell-what.html

http://986forum.com/forums/performance-technical-chat/77160-clutch-pedal-doesnt-return-smoothly-completely.html

http://986forum.com/forums/boxster-general-discussions/62567-clutch-booster-spring-possible-causing-clutch-slip.html

Simply removing the assist device (which contains the spring) will work for testing but it can intermittently disengage the cruise control. The assist device actually applies minor return pressure which fully depresses the clutch cruise control switch when the pedal is at top of travel. Also, the clutch assist device is under about 90lbs of spring pressure. You must be careful removing it because you can damage the car or sustain injury.