Recommend: Install new slave, push and use a LED borescope

Just finished the RMS, IMS, AOS, and clutch + flywheel replacement on my MY00 2.7. Turns out I'm going to need a new water pump now so I plan to do that with the motor mount next week.

Got the car all back together and was ready to test it out, but when I went to press the clutch pedal in, it felt unusually firm just to get it started. I continued to press and then I heard a loud "POP!". The pedal shot to the floor and would not come up on its own. With the car back up in the air, I pulled the pedal back up and lowered it back down again. From the back I could see that there was a hydraulic leak at the clutch slave cylinder. I pulled it out and I could see that the rubber boot on the press end had ruptured and it came off pretty easy from the rest of the unit. The rubber looked pretty tired and had shattered a bit around the collar.

I'm just really concerned because I don't want to put a new one in and have the same issue.

Obviously it's impossible for anyone to know without taking the whole thing apart again, but do you think there might be a greater issue that caused the cylinder to pop/break? That initial pressure needed to get the pedal to move at all was really disconcerting.

Any advice??? Thanks!

-Dwass

It can be a bear to wiggle it into place so that it is properly lined up.

Hey Boxterra,

Thanks so much for the reply, that's EXACTLY what I want to hear. If it's just that, I'm fine. I am just worried that it might be something worse! I did coat the guide tube with the Optimol MPO as it says to do. I feel like I did everything right. I mean, it wouldn't have come together if it wasn't.

My fear is that I'll install a new one and have the same issue. Any advice on getting it in? It's tricky to reach up there from under the car.

ALSO, here's a funny puzzler, I only had 5 bolts holding the trans to the engine! Not 6!!! I'm 99.999% sure this is the original clutch. Could Porsche have made a production mistake on my car? I plan to fix the missing bolt issue, but it's strange to say the least.

Thanks again!

-Dwass

before installation of the slave cylinder. If you don't getting it in place is a pain and it would be reasonably possible to rupture the rubber boot. It is possible to do without releasing the pressure but it is difficult since you have to wrestle it into place while screwing in a bolt that is difficult to access.

Which bolt is missing from the transmission? If it is the lower-left one, it is likely missing because that bolt is a pain to deal with and when the transmission was previously removed (for whatever reason) the bolt was not reinstalled.

Can you confirm if the leak was at the master (front) or slave (rear), just your wording was unclear (to me)

I would guess you have an issue inside the transmission / clutch. I agree your slave might have been misaligned, but a BIG might. I have installed the slave about 50 times! I have never had it misaligned, it is a big hole and the piston is quite small. Just remove the slave and check it, and/or take a digital image of it mounted and post it, I will tell you if its lined up.

I suppose it could be a failed pilot bearing or something else related to the clutch reinstallation. I have not heard of such a failure apart from pilot failures. I assume you changed the pilot bearings?

I am afraid you might have to remove the transmission again to visually inspect the clutch installation.

Good luck.

Hey Tnert!

Thanks so much for the reply. So when it happened, I immediately got the car back up in the air to see what was happening underneath. I pulled the pedal up and then pressed it down again. I could see that fluid at this point was pouring from the trans. I pulled the master slave assembly from the trans and the "ribs" of the boot has dents in them and there were little holes in the rubber. The rubber boot where the piston is came off easily from the rest of the unit and it appeared weak.

You mention the pilot bearing (I had hoped you wouldn't), I believe the new flywheel I installed had a new pilot bearing in the flywheel already. If it didn't, the clutch mandrel would have been wobbly and free when I put the clutch in. Are you also referring to the throw-out bearing? I got a new one of those when I got the clutch kit. Everything is OEM. The unit is 11 years old, maybe that has something to do with it. I've never pressed a clutch pedal in on a fresh clutch before, could it be tough on the first few presses?

We have a bore scope so maybe there's something we could see with that before I waste another one. I'd hate to take the whole thing apart again... I'll cross that bridge if I have to though.

Thanks again!!!

-Dwass

You need a new slave anyway, so go ahead and install and power bleed. Then if you have access to a LED illuminated borescope 9as you mention), then use the scope to watch the arm, throwout, and whatever else you can see as someone else puts mild pressure on the clutch pedal.

I have not noticed new clutches being much harder than the old ones. If anything they are easier to depress. The pressure point will move, but the total pressure should be the same or less, unless you installed a race clutch with heavy springs or something. The pressure should still feel progressive and the arm should still move in proportion to the pedal. I seem to recall a square hole that could be used for the borescope, but I am not sure what you will be able to see. I have a borescope with a digital camera integrated, if yours does not, you can always take a pic of the borescope LCD with a dig camera. I dont expect this to help because I cant even tell you what to look for specifically. I have not heard of the arm binding.

It sounds like you are well versed with the clutch install and you used a "kit" with the throw-out, clutch, pressure plate and you put lube on the guide.

I dont think I will be much help, i will review any dig images from the borescope. But i am quite interested in the outcome, so please post the resolution.