Dunkleblau S

I have a real stumper going on. At around 300 miles post delivery, I started having the clutch pedal stick to the floor when revving over 4000 rpm and trying to put it into gear. I took it to the dealer. They replaced the Master cylinder and checked the flywheel and clutch (because it really smoked!). They said they couldn't reproduce the problem, but did the replacements out of "goodwill"

The problem did not disappear. It happened again; this time I had the master tech in the car with me; shifting from 2nd to 3rd at 4000 rpm caused the pedal to stick to the floor (I had to pry it loose). This was not normal....they took the car in and replaced the slave cylinder this time.

It was symptom free for quite sometime, however when using the SPORT button and trying to "launch" the car, it would stick a bit. Given the fact that that Porsche NA gave me a CPO for my trouble and a visit to Zuffenhausen, I took what I got.

However, I just replaced the flywheel with an aasco single mass, changed the clutch to a Sachs Stage II with pressure plate and new throwout bearing. The guy who put it in is the best indy tech and shop in San Diego county. Unfortunately, the sticking pedal is back with a major vengeance. I push the clutch pedal in, rev to 5000 in neutral, and the pedal sticks to the floor! We checked the Master to slave pressure line - interestingly, there is no bleeder valve on the slave and there is a return line from the slave to master. I am hoping its just trapped air - but the fact the symptoms that were present when the car was brand new has me freaked.

The car is sitting at the dealer now. I have a good relationship with them (bought a used boxster for the wife), but I am worried they are going to blame my upgrades on the problem. I think the issue is hydraulics (a leak maybe??)

Any thoughts or advice on this very bizarre problem would be greatly appreciated!

I posted this request at 6speed and no answers yes...If someone understands why on earth there is a return line from the slave to the master cylinder, I would also like to understand -- perhaps there is a leak somewhere along the line...I can't think of any other components that might be to blame....

Viperbob1

This same thing happened to a customer at the racetrack this weekend. We just put in an Aasco flywheel, Pressure Plate and solid 4 paddle disc. We ran it for several days at track with no issues. I had an RSS clutch pedal travel limiter in it as this is a race car so it has no carpet and pedal goes way to far down. The limiter however moved and allowed the pedal to go all the way to the floor during one of the sessions. Since then, this happens everytime you push in the clutch at even moderate RPMs (limiter was reinstalled). Spoke to another buddy that spent 3 weeks working with a car having similar issues. They put in multiple PPs, discs, slaves, masters, etc. The prevailing cause seems to be that the aftermarket pressure plates fingers on diaphram can be pushed past center. At high RPMs this will then cause them to stick, and potentially damage the PP. Will be interested to hear what your shop came up with. I will be pulling this gearbox out tomorrow.

997_rich

You weren't totally clear in your description- when the clutch is stuck to the floor, is the engine engaged or no?

if the engine is engaged, then I'd look at the hydraulics again and the slave side etc.

is the engine is disengaged from the drive train, I'd look at the pedal assembly and the linkage to the master cyl. maybe even replace them outright.

Dunkleblau S

Engine engaged - turns out the Sachs Pressure plate I bought is the problem. Putting in OEM PP with sprung clutch -- everything is super sweet. Apparently Aasco is aware of the problem