earossi

For those of you that have done this job with the transmission mounted in the car, this is a royal PITA job. If the tranny is out of the car, it is about a 3 minute job to remove two 13mm nuts and stab a new slave cylinder in place. In the car, the cylinder sits on top of the tranny requiring a very long reach from below the car. And, since the cylinder is nestled right up against the body, it is usually a one arm job that is made more complicated by the fact that you really cannot even see the cylinder as you are attempting to mount it on its two studs. There are three things that have to be simultaneously addressed in order to mount the cylinder. #1 - you have to be certain that the cylinder piston rod indexes into the clutch return lever. Since both the piston rod and the return lever are "loose" it is not an easy task to be certain that they are correctly coupled. #2 - You have to slide the cylinder mounting flange "squarely" over the two short studs that bolt it to the tranny case. and #3 - you must compress the spring that holds the cylinder piston rod extended as you slide the assembly into place. The problem is that you must compress the spring as you slide the cylinder into position before it indexes onto the studs (the mounting flange really does not engage the two studs until you have almost fully compressed the spring).

Clearance issues around the cylinder just make things worse, since in most cases it is difficult to get more than a single hand in the area to do the assembly and when you do, you will find that you absolutely cannot see the area in which you are working. So, you are attempting to do this assembly single handed and in the dark!

There are two items that need to be removed from the car to clear the areas around the slave cylinder for access. First, remove the metal duct (driver side) that connects the heat exchangers to the car's heating ductwork. Simply remove a hose clamp on either end of the pipe and then remove the pipe. Secondly, remove two bolts from the tranny case that attach a 4 inch bracket that secures a vent line in place adjacent to the slave cylinder. Slide the bracket up the vent line and out of the way, and then drop the vent line downward 2-3" to free up the area right at the slave cylinder.

I worked at trying to install a new slave cylinder for an hour last night futilely attempting to stab the cylinder into place compressing the spring and capturing the two studs in one fluid motion without the ability to see what I was doing! This futile and wasted effort surely qualified as the perfect PITA job! I finally gave up.

If you have hung with me this far......there is a happy ending to this PITA job! If the mounting studs had been about 1 inch longer, you might have been able to slide the cylinder into place before having to compress the spring.

Well, I went to ACE hardware last night and purchased a 12" length of thin wall brass tubing. The tubing is sized perfectly to just slip over the slave cylinder mounting studs while still being able to slip through the mounting holes in the cylinder mounting flange. The tubing is 11/32" OD and has a wall thickness of 0.014". The label on the material I purchased identified it as made by K&S Engineering, Chicago, Il. The 12" part is labeled as "Stock #134". However, this is a standard item and should be easily sourced elsewhere.

I cut two sections from the tube, each approximately 3" in length. Be sure to ream out the cut ends since the soft brass bends in on itself if you cut it with a tubing cutter.

Then simply slide the two short sections over the existing mounting studs and then slide the slave cylinder over the brass sleeves. You will find that the cylinder will now easily slide squarely into place over the mounting studs. As you slide it towards the mounting flange, slip a finger into the space between the cylinder and the clutch return lever to facilitate indexing the cylinder piston rod into the indent in the clutch return lever. Be sure to put a dab of grease on the end of the piston rod so that the joint is lubricated well.

Once the return lever and piston rod are indexed, the slave cylinder will slide squarely and easily into place over the brass sleeves compressing the spring as it approaches the studs. Once the slave cylinder is in place and up against the mounting flange, simply hold the cylinder in place and wiggle the brass sleeves to remove them from the studs. You will find it easy to hold the cylinder in place while starting one of the mounting nuts on a stud. With one nut run down finger tight, you can now install the other nut. Then simply torque the nuts down.

Hard to believe that two 3" long brass sleeves turned an hour of frustration into a 2 minute job (really)!

If someone on this forum knows how to add this "job aid" to the DIY sections for the 993, I would appreciate knowing so that the item does not get lost.

AOW162435

Ernie,
Nice work. I've done this job twice - once on my 993 in a very, very cold metal storage unit, and the other time on a fellow Rennlister's 993.

Not fun. And yes, longer studs would make all the difference in the world.


Andreas

NC TRACKRAT

Excellent tip about the tubing! Be sure to "bench bleed" before installing. It saves a lot of aggrevation when bleeding the system...after you attach the brake fluid supply line while trying to minimize fluid dripping all over the place! Always wear eye protection any time you're underneath.

earossi

The 3" long ferrules that that slide over the existing studs give you the benefit of a "longer" stud to get the assembly oriented to slide into place. Using this job aide allows you to do the job blindly and feel your way through the job without the need to see what you are doing.

earossi

I have not yet bled the hydraulics circuit. Waiting for the new connector hose to arrive from Pelican. But, once I install the hose, I plan on using my Motive bleeder to do the system. Other than taking longer to fill the circuit, what would be the advantage to pre-filling the cylinder before installing on the car?

NC TRACKRAT

"Other than taking longer to fill the circuit, what would be the advantage to pre-filling the cylinder before installing on the car?"

Much quicker...Just less air to displace=Less aggrevation, less brake fluid used to bleed to system.

GregR

Hi Ernie,

This is a great write- up and was very useful yesterday when changing out my slave cylinder. I modified this approach slightly. Instead of using two brass tubes, I used one on the bottom and after validating the plunger was secured in the clutch fork, was able to swivel the top of the cylinder on to the stud.

Also, I still had a challenge holding the slave in place and putting the first nut on. So I found a way to hold the cylinder in place with my free hand. I used a paint stirring stick and By reaching around the back of the transmission I could put just enough pressure on the end of the slave to keep it in place.

Thanks again for this DIY - super helpful!

BobbyT

Small world--this was covered previously by IXLR8, even down to using the same tubing from the same manufacturer:

http://edelweiss.smugmug.com/Cars/Po...2835&k=wd7gTZT

IXLR8

Ernie and I have communicated via PMs and e-mail a lot in the past. It was Ernie's idea.

I initially cut the tubes to 3 inches as recommended. I found them to be too long or longer than they needed to be and ended up cutting them down to 2 inches.

BobbyT

Is this a great place or what? Porsche should pay you and Ernie to solve their service dilemmas.

IXLR8

Porsche shops have full height lifts so that this job is easy while standing. But my soon-to-be-installed MaxJax will do and will make life easier.

Although I am happy to have them, Porsche's factory repair manuals leave a lot to be desired when compared to the factory Toyota and Honda manuals that I have. The Ford factory manuals I once had were good for one thing...the wood stove.

alcanada

Yes I remember how frustrating DIY it was, great suggestion and simple to do. Otherwise, for those who haven't done it before, I suggest working out with one of those spring grips for a month first.