Re installing the clutch slave cylinder

What is the procedure to re install a clutch slave that I removed earlier? That spring inside of it is making it impossible to get the bolts lines up. I've tried draining the fluid and pulling some vacuum with a hand bleeder pump but still the spring keeps the push rod from fully contracting and the even pushing it in place with a prybar is not working. I can't get the slave cylinder to go in far enough to start even just one of the bolts. Anyone done this and how they did it? I must be missing something. My next try will be to put the slave cylinder in a wise and then try using dental floss to tie the pushrod to the body of the slave cylinder. I'm hoping this will work keeping the whole thing fully compressed until I can get at least one bolt in. I'm thinking that the dental floss is thin enough not to be an issue when is squeezes by the opening in the bell housing and strong enough to hold the spring in place. If anyone has a better or alternative method, please post it.

This is all I could find

Quotes source post: 16883898

Aaahaa!!! Awesome, thanks! Was thinking of doing this but was worried that it will damage the threads. Hopefully my sausage fingers can get in there to install the top bolt but I will give this a shot and report back.

Did you try with the fluid cap off the reservoir ? Gives fluid in the system chance to move back as you push the slave cylinder into place , worked when I did mine !

I tried and tried, and tried to do this. I FINALLY got it. Put the bolts in, got in the car, pressed the pedal and felt resistance, pressed it further and then it dropped to the floor. Despite getting it installed, the piston clearly wasn't aligned properly with the release fork. I ended up taking the transmission back out of the car, and installing a new slave cylinder, then putting it all back together. Anyway, best of luck. It isn't just you - it is a tricky thing to get back in properly.

I had to bear hug the transmission with one arm around each side and open the bleeder valve (with a power bleader on low (2-3psi)) with fluid gushing down every crevice to get it to compress BARELY enough to start the bolts. Was the worst experience so far with my 911.....

Get a hose clamp off tool. The one that squeezes a fluid line closed. Take the slave cylinder in the palm of your hand and push the push rod in against something solid. Take the hose clamp off tool and clamp off the flexible hose, preventing the fluid from going back into the cylinder, this should take all the tension off of the push rod and make it almost floppy. Install the slave cylinder into the transmission making sure to keep the push rod aligned. Once both bolts are in, remove the clamp off tool. The first press or two of the clutch pedal might feel weird as the push rod aligns itself. There are risks to using this method however I have never had a problem. Edit: https://www.harborfreight.com/4-piec...set-65116.html

Quotes source post: 16884183

Same thing happened to me the first time I put the slave cylinder in but then when I took it out, I was able to put the piston back in. Now I know how it supposed to feel when the pushrod is in the proper spot but that makes the bolt hole really far away and that's when I ran into the problem of getting them to line up and decided to post this thread.

Quotes source post: 16884549

I've passed that point since the line is already fully drained. The line is clamped but with air in it however, I have used a vacuum brake bleeder to puss as much as as I can from the bleeder screw while the pushrod was push all the way in. This helped a lot but the sling still has enough tension that lining up the bolt holes was not possible. I will try the drift punch method next.

This was the hardest part of putting my car back together after installing the IMS Solution!!! This was even more difficult that aligning the transmission properly to get it installed.

Quotes source post: 16885205

This ^^^ ... I spent more time trying to get the cylinder back on the first time than I did removing the transmission to put the new one one. If I ever have to drop the transmission again, I'm definitely just going to take the line off the cylinder and leave it on the transmission. Bleeding the thing is 100x easier than trying to reinstall it while in the car.

I was struggling with the install as well. Found this post and followed kwrights suggestion of pushing the piston in by hand and clamping off the line. Still struggled for quite a while getting it lined up and then decided to put a little bit of synthentic grease on the rubber boot where it contacts the transmission housing and it literally slid right in. The clamp trick definitely made the pushing part simple but the lube was the key. My friend and I spent over an hour messing around with this and it took five seconds once lubricated.

Quotes source post: 16885427

I had no issue with getting the SC back on. Getting trans in was a whole nother story.

Quotes source post: 17044266

Initially I had trouble getting the transmission on because the clutch wasn't aligned properly (cheap plastic alignment tool with poor tolerance). I loosened up the flywheel and eyeballed the alignment - then it wasn't too bad. In fact, I ended up doing it twice due to the issue with the slave cylinder.

Quotes source post: 17044409

Yup the plastic tool allows gravity to allow a hair of sag making for an impossible install. Then the motor and trans angle need to be perfect. In the long run, dropping the motor and trans as one unit would have saved me a day of time.

Quotes source post: 17044484

This is where a some electrical tape comes in play. Fatten up the tool with it until it's snug in the clutch.

That slave cylinder installation Is not easy. In the end I used a ratchet strap to compress it to its limit and squeeze the hose with a clamp tool for that purpose. Also a bit a grease on the rubber boot large end. Bolts went in with fingers, I did not enjoy that part. F

Quotes source post: 16884565

I happened to me too! I ended up being able to muscle it in place while starting the top bolt....with one hand. I'm not sure how but I thought I'd never get it

Quotes source post: 17044239

THAT explains what I was running in to!

At least for an engine drop; I�ve found that there is enough wiggle room in the hose that before I�ve lifted the trans/engine all the way up; while I still have better access I could install the slave clutch. I think I actually reached in through the engine bay more or less laying over the intake manifold. Way more leverage this way than laying on the ground. like others I once jammed and cursed and prodded it into its spot only have learned after the fact that it wasn�t lined up; fluid gushed out... New slave ordered. That was an unpleasant day...

Quotes source post: 17441367

Next time, you can just push back the popped out piston. There is nothing wrong with with it.

I struggled mightily with this. Slightly different solution worked for me : I attached a hose barb fitting to the brake fluid inlet on the slave (off the car). Then I ran a hose to a hand vacuum pump, and sucked the pressure down to -20hg. That produced a much softer spring to compress. The fitting I used was a 12mmx1.0 male to 1/4 NPT female, and then a 1/4 NPT male to hose barb (5mm). https://www.fittings.space/gbm22-04zf-m12x10mc As an aside, the above suggestions didn't work for me : compressing the piston then clamping the line (I don't think my clamps totally cut all fluid off), it was still super stiff for me. I also tried zip-tieing the piston in the short position, but that didn't work either and I wouldn't recommend it : I eventually tore the book and had to get a whole new slave.

Quotes source post: 16885205

I absolutely agree... this was the biggest PIA of the entire gbox installation. Hell, I struggled for 3 hours just getting the two bolts on the slave cylinder back in. I even almost accidentally cross threaded the bottom bolt and ended-up pulling it out [the bolt] and kept starting it all over again until it threaded correctly. It just took a lot of f-words and a ton of patience... 3 hours for two damn bolts!

Since there are still people doing this clutch cylinder, and it is still insanely fussy to do, I will add another note. Thanks for taking the time to post everyone, it helped get the job done, Pin the bottom hole, lithium grease the rubber boot, check. I noticed that the metal tubing coil can hinder moving it in place and compressing, so do make sure it is bent enough to clear the surrounding components. Also, definitely remove the 2 bolts and bracket that holds the brake tube on top of the transaxle output cover. Precious maneuvering room. Finally, I benefited from several skinny flex drives and sockets in 1/4" drive with a variety of extensions. Good luck!

Bumping this older thread. Similar to others here, I struggled to get the slave back in and unknowingly the rod was misaligned and not properly seated in the throw-out lever pocket. So when attempting to bleed, the piston push out and leaked brake fluid into the bell housing. Best to drop the trans and clean the brake fluid off the clutch assembly? Seems likely that the fluid got on a lot parts that you don't want it on... And when shopping for a new slave cylinder, I'm seeing a lot of the p/n's discontinued or out of stock. The common aftermarket vendors have a $17 Sachs cylinder that seems too good to be true - is that just a seal kit? The Porsche part is $300 +/-. Thanks for any quick insights.

I would not remove the trans, brake fluid is water soluble, it washes off easily with just plain water, then you can dry it with compressed air... Note : just don't get any brake fluid on painted surfaces, brake fluid does nasty things to Paint...

So if I were lazy, I could leave the brake fluid on the transmission?

Yea it will evaporate off the aluminum surfaces.

The brake fluid drained thru the bell housing, coming out the bottom cutout for the LN IMS oil feed line. Not worried about steel/alum parts, but concerned about the lube on the guide tube & shaft splines, any rubber, maybe the throw-out bearing, and the clutch disc material absorbing it.

How does the slave cylinder not line up perfectly with the clutch arm when the cylinder is bolted into position?

I ended up disconnecting the hydraulic line, installed the slave cylinder, reconnected the line, and then bled the system. Is there any downside to doing it this way?

Quotes source post: 20569626

Thats the way to do it, easy peasy....

Bleeding the slave is no fun. I used to disconnect the line. then I started working smarter not harder. with the trans on a jack about 2 ft away (lower) from its final destination, take advantage of the room and put the slave in. Then give it the reach around into the bell housing to make sure the fork is in the right place. then put the trans in. no fluid everywhere and cross threading the bolts for the slave. �Aaron

That assumes the transmission is separated from the engine?

Quotes source post: 20569868

yes. If you�re just replacing the slave, slow gradual pressure will get it in place without disconnecting lines etc. Lower the gearbox to get more room to do so. Not fun, but not impossible if you take your time and use slow pressure to push in the slave.

what's going to be hysterical is when I do the replacement with the trans still in the car, and then find out that it wasn't the slave cylinder, but the clutch, and I have to drop the tranmission anyway lol. the car stalls if i try to pull out in 3rd gear though, so I think the clutch is still in good shape. we'll find out soon enough.