I couldn’t find an identical issue as the one I had today and I need help understanding the pedal behavior.
I was in the car and it was off in my garage for the last 3 weeks during an Aquamist install. I was ready to start it and pressed the clutch to the floor...and stayed there after I lifted my foot. I have it in neutral so I can start it with the clutch down, but to get the clutch pedal back up I have to pull it with my hand. Then pressing it just sends it to the floor. The pedal feel was still well assisted after weeks of not running so the accumulator seems fine. It’s as if the clutch master and slave are somehow not connected.
The failure occurred suddenly and the master, slave and accumulate have about 1000 miles on them. There is no fluid leaking with the exception of some drops on the clutch master cylinder on on the firewall. Is there a way I can test what the potential problem is? I have an led-lit inspection endoscopic camera that can fit into an opening 3/8 inches in diameter.
The worst part is I spent a month doing the Aquamist install and the moment I’m done testing the installation and ready for a test drive...this happens.

 

Failed pressure bearing, misplaced clutch fork or hydraulic line going to slave accidentally squeezed flat (with lift or jack).

 

You say there's no fluid leaking, but then say there is fluid leaking.

 

Yes - I meant that there is no obvious puddle under the bell housing in the back or the master cylinder in the front. The master just had drops of pentosin around the cap, that's all. Sorry for the confusion.

 

More detail on the problem - when it first happened I was trying to press the clutch pedal while standing outside the car to start it (testing new Aquamist) and my foot slipped off the clutch. The pedal popped back up but the next time I pressed it, I pushed down about 1/2 inch with my foot and it was as if someone pulled the pedal to the floor - and it stayed there.
I can pull it back up by hand, but each time I start pressing it now it just gets pulled to the floor, as if a vacuum is sucking it down.
I was asking about an inspection hole in the transmission as it seems like when the pedal popped back up when my foot slipped, something got disconnected that actuates the T.O. bearing because there is nothing resisting the assistance of the accumulator now.
I just want to look in the clutch housing with my endoscopic camera to validate my theory but I don't know where to look.
I found the invoice for the clutch work and it was all new in 2016 including the hydraulics on both ends and accumulator.
This sucks a$$...i just got my meth kit installed and I can't even take it out of the garage

 

i also am going with somehow disconnected line, given no obvious fluid leaks at the master. it's nothing to do with the accumulator.

my best guess would be to visually trace all the hydraulics for integrity first.

 

I double-checked the invoice for the clutch install and the only thing not replaced was the master. I called my mechanic today and he told me where the inspection hole is on the transmission so I'm going to see what is happening to the release mechanism when the pedal is pressed.
In any case, after spending the last month installing my Aquamist setup and redoing all my gauges it looks like I will be waiting at least another week to drive it again since I am in no mood to work on the car right now.
It's really fun doing mod and upgrade work but transmission work is not for me and honestly I'm just tired of being in my garage on nights and weekends.
I am just thankful my mechanic is honest and reasonable. In the Bay Area that's as easy to find as a unicorn.
I've driven the care less than 500 miles in the last 12 months and I really miss it.

 

ya, that sucks. it's a simple thing i'd bet. when the master fails ( as you know ) there are "signs". clutch fork or TO issues would've also appeared sooner is my guess.

driving season is here! so GL man. just watch out for for brown streets up there

 

You might check the rod and Clovis pin that connects the clutch pedal to the master cyl. That would explain this behavior. The pedal will fall to the floor because of the helper spring at the pedal. The clutch mechanism may be OK as evidenced by no leaking fluid. THe hard part of this is the difficulty of working on the clutch master cyl under the dash. It is very difficult for a tall old man like me.

 

great advice ^

 

Master is bad. You see this when the gt2 conversion is done and all the pentosin is not flushed out.

 

At this point logic points to the MC. The way that it failed - engine off and clutch pedal springing from floor to raised position after my foot slipping off does make me think it has something to do with a failure in the physical linkage at some point in the system and the way the pedal feels like it is not connected to anything and just drops to the floor at the slightest push and then can be pulled back up against slight resistance makes it seem like the pedal and MC may not even be linked together.
I’ll start with the MC to pedal linkage and work my way backward.
Just what I wanted to do on a beautiful Sunday. It’s a labor of love I guess.

Thanks to both of you for the helpful replies. It’s great to see Tim941NYC posting on this forum again. It’s been a while!

 

Thank you. The rubber seal in the master is very flimsy all's it takes is a little nick and its all over. I have seen a few. If you have the gt2 conversion you can unbolt the slave from the trans and let it fully extend (fill it with fluid) then replace you master then place the slave back into the trans (compressing it) and the brake fluid will go through the master top off the fluid and you will not need to bleed it. This may also work on the assisted slave but I have never tried it.

Tim

 

My car still has the stock assisted setup. I got under the dash and saw everything was still linked together properly so I replaced the master and it's back to normal. That was odd how it went from working perfectly fine to having no ability to move fluid instantly. I'm really glad I wasn't on the road when it happened.

 

The new master cylinder is working fine but the clutch feel is definitely not how it should be. I thought it would normalize after a few days but it hasn't. The best way I can describe it is that it feels sticky and slow (pedal response) for the first few minutes of driving. Also, after sitting overnight pedal resistance feels completely unassisted when pressing it to start the car. This makes it very hard to leave from a stop because the clutch action is very inconsistent and delayed. Even after the car is warmed up, if I shut it off for a minute and then get back on the road it still takes a few minutes to feel normal and have a consistent release point.
My understanding of the operation of the hydraulic clutch on a 996TT is that it is assisted using vacuum stored in an accumulator. If it's functioning properly it continues to function long after the car is shut off and still offers assistance even when starting up after a week or more without running when the system is healthy.
My point being it seems like two things are wrong now...the accumulator leaking and a lack of clutch feel during the first few minutes of operation.
On the bright side it has warmed up here and I got the Aquamist dialed in running 50/50 H20/Meth and it has the same power on a 90degree day after repeated heavy power applications as it has in the past in 50 degree weather just after reaching operating temperature.
Maybe after this last trip to the shop I can finally have it dialed-in perfectly. At least I don't have to bring it there on a flatbed this time