JerryW

I'd appreciate some help here diagnosing a clutch problem. On my way to work this morning in the 964 I'd been driving for about 40 mins when at a traffic light I suffered a clutch problem. Symptoms were that I had some resistance to pushing in the clutch as I slowed for the light changing followed by a snapping sound and the clutch pedal falling to the floor.

Oh I hear you all saying -- That's an easy one-- roll pin sheared. Nope !

Once home (Tow truck took forever !) I removed the floor board to check out whats wrong. Here's what I found

1) Pulled the pedal back to normal position -- applied pressure. Pedal attempts to push Master Cylinder pushrod just fine -- not the roll pin . White block holding spring adjuster moves somewhat when pressure applied to pedal. Don't know if it's supposed to.

2) Disconected the Pedal from the pushrod -- Pedal moves fine but does overcenter on the return spring system and will go all the way to the floor.

3)Manually (not overly hard) attempt to push pushrod. No movement obtainable.

4) Reconnect pushrod to pedal. Push pedal using feet. No movement from pedal (apart from the normal free play of a cm or so) , unable to apply clutch. (Don't try to use too much force with feet as I don't want to break anything else).

So I'm thinking that I'm either facing a swap of the master and slave cylinders or a clutch job.

Can anyone suggest further tests to indicate where to go next in the diagnosis or should I just bite the bullet and start ordering parts ?
I can post pictures if it would help.

Thanks

Indycam

Crack the bleed nipple and see if you can push fluid out the nipple .
If the clutch pedal can be depressed while the bleed nipple is open , the problem is down stream from the master cylinder .

JerryW

Thanks -- good idea. I'll try that after the Sharks game ends.

JerryW

So followed Indycam's suggestion and tried bleeding the slave cylinder. Using both pedal pressure and a motive we were able to bleed the system just fine. Pedal pushes the master cylinder (and fliud) with no problem. I pulled the inspection cover and the boot over the finger has broken and it looks like the finger is extended (but I don't know if that is the normal look).

Looks like Sunday I get to pull the slave cylinder and see if it is that or the fork that is broken.

Indycam

Good news / bad news
GN = not the master
BN = Its in the bell houseing ? I think its unlikely to be the slave .
The snap + the pedal staying down does not sound like a slave cylinder going bad .
I'm ah guessing your forked .
When the part broke and you picked up the pedal , the slave was at near full stroke out , slave piston at the far end of the slave cylinder , when you pushed down on the pedal the slave piston could not go out anymore than it allready had so the padal was locked up .


I didn't suggest bleeding the slave , I suggested opening / splitting the system to disconect the master from the slave and other parts .

JerryW

You guided me to the bleed nipple -- That made me think of bleeding. Anyway thanks, I'm going to pull the slave cylinder tomorrow and see if the shift fork moves once pressure is off. If that doesn't clear anything I guess it's time for a clutch job.

Indycam

You will never guess what nipples make me think of .

JerryW

Yup - but I was in such a bad mood yesterday my wife says, that I wouldn't have been able to get near any real ones !