Help! What on earth just happened to my clutch?!?

[Z06C5R]

So my clutch pedal just failed in a very peculiar way... It went all the way to the floor, where it is now stuck, completely on it's own.

The pedal has always felt a bit odd to me, but it's never been abnormal or anything so I just chalked it up as a light clutch. It's always felt a little like there might be a small bubble in the hydraulic line - the beginning few inches of travel were a bit light, but some clutches are just like that from slack in the mechanical components or what have you. So today I was going through a few little issues on the car I wanted to address, and I thought I'd try depressing the clutch a few times by hand to see if I could determine if the assembly that the pedal pivots on was in need of tightening. I depressed it a few times by hand and indeed the first few inches of travel were very loose, and the pedal was hanging up a bit when I released pressure from it. Then all of a sudden, it wouldn't come back at all, and it started to push itself to the floor completely on it's own. It is currently stuck on the floor, and won't seem to come back.

So what the hell happened? I can only assume something broke and it failed open or something, but the clutch was just replaced by a Porsche mechanic a few years ago... I'm really hoping this isn't serious, because I can't really afford any major work on the Porsche right now and I really don't want to have to drive my Z daily, even though she's MUCH nicer to me.

[Dantilla]

Hydraulic issue.

The clutch is most likely just fine, but there is a helper spring to keep clutch forces light since there is considerable clamping force.

If the clutch system looses hydraulic pressure, the helper spring will push the pedal to the floor.

Step 1:

Where is the puddle of fluid under the car? If there is none, it's either the master cylinder or slave cylinder. You may as well do what most people do, and chance them both at once.

[Z06C5R]

No puddle anywhere, so I guess it's either the master or the slave then. I'm hoping this is an easy DIY job, though this car has thus far proven to challenge my concept of "easy".

Any word as to what to order? I'm guessing the best bet is just to get the OEM parts on here...

[nize]

first, check your hydraulic fluid level, is it full? if it ran low it's possible you introduced air into the system. a quick fix would be to re-fill and bleed the system, which would be much easier than replacing the master/clutch cylinders.

replacement procedures are here;

master;
http://www.clarks-garage.com/shop-manual/clutch-04.htm

slave;
http://www.clarks-garage.com/shop-manual/clutch-02.htm

[Tishabet]

Definitely a do it yourself job, I'd estimate 2 hours and a busted knuckle to change and bleed the master and slave. The links nize posted are the way to go.

[2Tight]

I'm sure you know it's always best to replace both units together? While you are in there you could replace the hydraulic line between the master and slave and be done with it for years to come.

[Z06C5R]

Yeah, the brake / clutch reservoir is full to the top, so it's definitely one of the two whosamajiggers. I'll pull em' and replace 'em asap. Fortunately, it looks like no real rain for the next few days - the Z doesn't like the rain...

[nize]

it could also be possible that the clutch fork broke. it's happened to me before. replacing that would basically require a clutch job.

[Z06C5R]

God forbid - According to the records that came with the car, the labor alone on a clutch job is like $700... At any rate, how would I diagnose that?

I thought a well-maintained 944 was supposed to be fairly reliable, no?

[bud9344]

It is usually the slave unit that fail. Good idea to replace them booth .
The hard part is to replace the the master cylinder (cramp space) tuck between the side wall and brake booster and also bleeding the clutch is tricky
Let me know if you need some advice about bleeding

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1986 951 black on black Daily driver
1987 944S Son daily driver
1986 944 red (totalled)
1983 944 Auto
1983 944 Black used up master and slave till I clean the hydraulic bowl

[bud9344]

It is usually the slave unit that fail. Good idea to replace them booth .
The hard part is to replace the the master cylinder (cramp space) tuck between the side wall and brake booster and also bleeding the clutch is tricky
Let me know if you need some advice about bleeding

----------------------------------
1986 951 black on black Daily driver
1987 944S Son daily driver
1986 944 red (totalled)
1983 944 Auto
1983 944 Black used up master and slave till I clean the hydraulic bowl

[Z06C5R]

Yeah, I'll probably need some details on bleeding the master - Clark's only outlines how to do it w/ a power bleeder. I'll probably be doing the job Thursday afternoon, so I'll probably post up another topic on how to bleed the master Wednesday evening.

[nize]

you can visibly check the clutch fork from under the car;
http://www.clarks-garage.com/shop-manual/clutch-03.htm

[nize]

if you don't have a power bleeder, you will need two people to bleed the clutch system properly. one person to push the pedal and the other to open/close the bleeder valve.

[Z06C5R]

Typical bleeding procedure then, ok. In review of the Clark's page on the master, is seems like there might only be a bleeder on the slave? They do refer to one on the master, but it seems like a typo in the context it's is. Not sure why you'd have to go under the car to get to a bleeder valve on the master...

[2Tight]

Again, make sure it's not that connector hose that failed. Pull the rubber inspection plug off of the bellhousing and rub your finger over the area where the slave enters...if it's wet it's shot. Pull the rubber boot back where the clutch/master rod goes through the firewall (interior), if the boot is wet inside it's bad; if there's a puddle on the ground at all on the passenger side it's likely the hose, they do fail and always at the worst time.

[flash968]

assuming it's built like the 968, i'd check the high pressure hose from the master cylinder - these are blowing everywhere lately - they are old and well beyond their lifespan

[Z06C5R]

I assume there'd be a substantial fluid puddle somewhere if any sort of line blew out, and there is no such puddle. The hp hose looked good on the master side, but I haven't looked at the slave side yet.

[flash968]

not necessarily - yes, when the hose blows, you lose the fluid, but it generally just falls to the ground - really hard to see the failure - many times, you won't see it unless you have somebody else push the pedal while you look at the hose - the scarey thing is when you see the hose expand like a balloon - in this scenario, there is no fluid loss at all

either scenario will create the symptom you describe

[bud9344]

There is another way to check. Lift the pedal up by hand, it will stay up. Then operate the pedal like you normally do (Changing gear). If that is back like it used to be then your slave unit has an internal leak. It bleed slowly as you push the pedal and looses pressure.
I drove my car like that a couple off time to go from home to the shop. Sometime I forget I have clutch problem waited on a traffic light and the pedal doesn't go up, I have to lift it up with tip off my shoe under the pedal and pumping quick to built up pressure.

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Bud