Sudden strange problem with clutch
 

Hello, everyone

I have 2007 997 Turbo, manual. 57800 miles on the clock.
I've done big service 4 weeks ago at official Porsche dealer, including ignition coils and transmission oil change.

Car has been standing for the last 3 weeks, decided to take it out for a spin just now.

I start it, starts normally, I depress the clutch, and the clutch pedal goes "through the floor".
Now it has no resistance and it sits much deeper down. Also, it engages fully immediately, as soon as I let it go just a little bit the car jumps forward even without extra throttle.

Checked front pentosin container - does not leak (I had clutch accumulator replaced 3 years ago). Checked the rear pentosin container - it is at correct level for cold engine.

What can it be? :(

Did you have a brake fluid service done too? Brake fluid and clutch fluid are a shared system on the 997, iirc. Might be a link here.

What do you mean "goes through the floor"??

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I think hes referring to the pedal going all the way down to the floor, without much/any resistance

No, brake fluid was not changed as I had it changed last year when I changed brake discs and brake pads on all four corners (I drive the car very little since I started motorbiking).

What I mean with "going through the floor" is that when I depressed it it was too light and it did not come back all the way up. I pumped it a few times and it is just too soft, almost no resistance. I can disengage the cluch (thank God) but when I try to engage it, it engages immediately with only a minor release of the pedal and the car jumps forward almost stalling (I give very little gas), the clutch is not slipping when I try to release it.

Exactly. Goes to the floor with unusually little resistance and does not come back up fully.

Should I refill the front pentosin container a bit? It is dry up there but does not seem full to the brim.

Are you sure? Brake fluid is a different reservoir on the 997TT and I don't think it uses pentosin. Guys who track their cars upgrade the brake fluid so don't see how these systems are shared. Where are you getting your info?

Like I said. IIRC.

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I'm guessing it's your clutch accumulator and slave again. I just had mine replaced and that is exactly what happened in my car.

Monitor the front pentosin container closely. I'd guess you have a slow leak.

Well, I replaced the accumulator 3 years ago. After that the front pentosin container was still leaking, but I drove the car for 3 years and 30000km no problem. Since a while back the front container is not leaking, but when I check the main container in the engine the level is good.
Can I pour some pentosin in front container then?

P.S. I am getting really p. off by this accumulator-slave problem. Bad engineering on Porsche's part, but why should I pay for this?! :grr:

OK you guys. Thanks for the comments!

I went down to the garage, unscrewed front pentosin container, took the plastic cover out - it was bone dry in there!

Refilled with Pentosin to the brim (I have a can, thankfully). Sat in the car, started pumping the clutch, after a few times it became really rigid, but did not go all the way out yet.

Started the car, started pumping again. Pedal does not come out fully but the clutch engages fully immediately, just like an hour ago. Then I ventured out on the street anyway. After a bit of driving the pedal was all the way out, the feel was back, everything normal!

There is no puddle of liquid under the car. There is no dried out puddle either. Large service was done 4 weeks ago, already then the pentosin was probably almost gone, but Porsche mentioned nothing.
They must have checked under the car, at least they told me the engine was a bit dirty underneath, but they did not see any leaking fluid.
So where did all this Pentosin go? The slave cylinder is somewhere above engine? Maybe that dirt on the bottom of the engine is actually leaking pentosin? But isn't it flammable?
I am at a loss. At least the car drives now.

Is it possible that you have air in the system?
(If it is not leaking?)

I'd bet money you have another leak. Refilling the reservoir is a temporary solution.

Agree with Ray
The pwr steering and clutch accumulator share the same reservoir

OK, thanks for the heads-up, guys. :(

I think I have to ditch the car. 58000 miles, 8 years, now it will require its fair share of repairs, I guess.

Seems a bit of an overreaction, but i don't know what other money you've put into it. It's about a $1k job to replace the slave, accumulator, and bleed it all out.