From the time I purchased my car back in January, I have had a problem with a hard to press clutch pedal. I have cleaned and lubed the pivots under the floorboard, backed off on the preload spring and flushed the slave cylinder with some/little improvement.

This weekend I decided to replace the clutch slave cylinder to see if that would help. Simple enough, I thought to myself... how hard can this be? Armed with Robin's DIY and a new slave cylinder, I set to work. For the most part the instructions that are listed on the DIY are right on. Everything is pretty much as explained... well, almost.

Getting the old part out was no problem. The real problem started when I tried putting the new part back on. The slave cylinder has a "rod" that must be fitted into a detent on the clutch arm. This detent can only be felt through a hole that the slave cylinder mounts through. So essentially, you try to feel for the rod to be in place, then push the new slave cylinder into place onto the 2 mounting studs while fighting the clutch arm spring tension.... using only one arm. To make matter worse, you need to put a nut onto one of the mounting studs to keep it in place after you get everything lined up. Almost impossible! I can't see how people do this using only one hand... but they must because there is no room for you to get two arms up into that area.

Struggle, struggle and I finally get the new unit into place. Hmm... that was a bit too easy, I think to myself. Oh, well.. bleed the clutch and now the moment of truth. Step on the clutch pedal and I hear a grinding sound about halfway down and then it just stops dead in it's travel. Push some more... Yep... definitely stuck.

So, removed the 2 mounting nuts to get the "new" unit back out and find it will not come out. Tug and pull and finally the body comes out leaving the rod portion still stuck in the mounting hole. Brake fluid dripping down, I yank on the remaining portions of the "new" slave cylinder and out comes the rod, rubber boot, and spring that are the internals of the slave cylinder. This can't be good, I think to myself... DUH!!

Upon inspection, I figured I had not gotten the rod portion into the detent and most likely it was off to the side of the clutch arm and had gotten wedged between the housing and the arm when I stepped on the clutch pedal.

I decided to put my old slave back in, but was very reluctant to do so in fear of screwing up another slave. After struggling for about an hour or so, I came to the realization that it was impossible for me to put this back together properly using only one hand.

Looking at the space available, I found that if I removed the heat exchanger tube running in that area, I could barely squeeze both my arms up into that area to get the slave in position and thread a nut onto the stud to hold it in position. Success! I finally get the "old" slave mounted. Bleed the clutch and step on the pedal and it works like it should. WHEW!!!

The nagging question that I had was, "How can I tell before I step on the clutch pedal if I have properly aligned the rod with the clutch arm?" The answer is, after you get the slave mounted, but before you tighten down the nuts, try pushing the slave cylinder in by hand to see if you feel any "springiness". If it does not push back and you feel no "give", you most likely have the rod misaligned and it is wedged between the clutch housing and the arm. If you do feel a "springiness", you most likely have it aligned properly and are feeling either the clutch return spring or the slave return spring movement. In any case, you will know that nothing is binding and the rod is aligned properly in the detent in the clutch arm.

I have a clutch pedal that is working a bit smoother than when I started, I think, due to the fact that I ran about a quart of fluid through there with the two bleedings I had to do.

I know I'll have to go back and do this again someday soon, but at least I'll be armed with some knowledge as to what to expect and how I can make the job easier. I hope if you plan to do this, you can learn from my mistake and avoid some headaches for yourselves.

So, for something that should have taken about an hour or two to complete, I ended up spending the entire day learning the ins and outs of clutch slave cylinder replacement.

Now... where did I put that beer????

 

Yes it's difficult, but you were on the right track. Definitely remove the driver's side heat tube to get your arm up there. Also, there's a black rubber plug on the driver's side that's designed to allow you to remove the tape you have to use to hold the release arm in place when you install the transmission to the engine. If you remove that you can easily tell if the slave cylinder end is in the cup in the release arm.

I wish I had taken a picture of it, but check your PMs.

Chris.

 

Thanks for the tips all! This is the next item for me to do the next time my car is in the air. I got the new slave, just have not had the time to get it done..

 

Chris L- Wow! thanks for the tip on the rubber plug. I didn't even bother looking for something like that at the time. If what you say is true, putting my next one in will be a breeze. Thanks for that important tip.


Chris W- Good luck. I was hoping that by posting my mini novel someone would benefit.

 

You just described my slave cylinder R&R last year to a 'T'.

 

Doing the slave cylinder is always a fun job. Believe it or not, I find it easier to do on my garage floor than doing it on a lift... I seem to be at a better angle to get my arms up there.

Good job though Kelly... I hope you also replaced the clutch hose while you were there....

 

Robert H- nice to know I'm not the only one who ever ran into this problem. Did you end up destroying your brand new slave too?


Bob- I took a look at the hose and it looked fine to me. Other than looks, how can I tell if it needs replacement?

I believe you about doing this on the floor instead of up on a lift. I had to contort my body in a number of different angles and positions to do various things while working up in the area. I found myself pushing with my feet on the passenger side rear tire for added leverage in certain positions.

Did you know about that rubber plug that Chris L talks about? Man, that would have made my life a lot easier had someone mentioned that before.

 

Well, I definitely separated the piston from the housing. And the piston wound up bouncing across the garage floor when I finally yanked the unit free from where it had jammed. I initially stuck the two back together & reinstalled it, but couldn't feel any benefit from the end result. So to be on the safe side, I went ahead & installed a second new cylinder - with the same lack of benefit.

So I still need to try clean/lube the pedal assembly, etc.

 

I did this exactl same job and in exactly the same way on my '87 Carrera. Of course, I had the added pleasure of being in a dark parking lot for the job. When I stepped on the pedal, it got very stiff. I gave some more pressure and heard a loud popping noise, followed by a stream of ATE blue under the car. I gave up and had it towed to a shop that so gouged me and then handed the car back without having bled the slave fully. So I made it almost home from the shop before my pedal stuck to the floor. That was a $500 lesson I shall never repeat and I never miss a chance to PM people asking about shops in this area, telling them to stear clear of this one.

Once I got the 993 and read that clutch slaves were also high failure points on these cars, I set about flushing it regularly. First time I did it - about 1000 miles after the 30k miles service had been done, what came out of the slave looked like used motor oil. I bleed it about every 3-4 mos. now. When replacement become inevitable, I shall reread this thread and put on my best DIY face.

 

wow, deja-vu. I think it was about 8 or 9 months ago, this nightmare gave me the test.

Seems like there's been a few of us that've gone through this fun exercise...I ended up reseating the guts of the new slave back together and reinstalling it (after the 3rd or 4th time)...

I think the final time I did this, I had it down to about 15 mins for the slave R&R....and I really didn't want all that practice.

-travis
RLM#: 040510-3618

 

Thanks for the added info and sharing of your particular experience with r&r of the slave. Makes me feel a bit better knowing I'm not the only one to ever go through this fire drill.

Like I said, it seemed easy enough when reading about it on Robin's site, but with the added bits of info from you all, I think this DIY should be updated, at least.

Good luck to all in the future.

 

Well it looks like I'm not the only one who struggled with replacing the slave clutch cylinder on a 993. Took me 4 hours yesterday. Once I bled everything I realized the clutch slave cylinder was not lined up with the clutch throwout fork. I had to disassemble and reassemble the slave cylinder. That was another 3 hours today. This is more of a pain than taking an engine out...

Note to the Cheap:
A regular air compressor set on 20 PSI and hooked to the tank vent line (the one that runs up the trunk side) works fine if you are willing to continuously refill the tank. If the level goes just a tad too low you are SOL as air gets in the line and you have to start over.

 

Removing the cap off the brake reservoir allows you to reinstall the slave without having that fluid backpressure which makes it difficult to push the unit back onto the two studs.

 

Thanks Fred for the tip. It does seem like an updated DIY is in order:
- keep tank full at all times when bleeding
- use compressor on tank vent line if no power bleeder
- take cap off tank to install slave cyl
- pray you never have to actually go through with it.
Dropping the engine on my C2 was easier ...

 

Would any of you learned slave cylinder changers consider rewriting or adding to the DIY on Robin's p-car.com website? Just a suggestion because it seems to be the most effective method of sharing your lessons learned with lots of other home mechanic DIYers (like me!!!).