Dave928S

I sure did!

I made the totally wrong assumption from the very clear original post, that the slave cylinder was hanging down when delivered, but that it wouldn't have been left that way.

Jim is absolutely correct ... it's very likely that's your hydraulic failure, and the reason for the pedal going to the floor. As he also pointed out, check everything else as well, in case there's a secondary problem (like the wire shims).

As your car is partially disassembled, and you don't know what's complete, lots of pictures will help in resolving this, or any other problem. It may be that there are things missing, or not right, that will be obvious in photos.

Landseer

Project unfinished by somebody else?
That car is apart for a reason.
I wouldn't even bother trying to move forward with assembling to try it.

Remove master, slave and clutch. Take complete inventory of what is there and clean it all.

Determine if the master is a replacement that has the notorious long piston. That alone is a hidden problem that only a handful of people realize exists and it will drive you crazy.

Ensure the slave rod length is correct.

Ensure the short shaft splines are intact, smooth, an lubricated with the proper Porsche lube or at least some open gear spray grease.

Rescues like this are much easier if you take a couple steps back.

Dave928S

^^^^
Good advice .... until you know precisely what you have, and what's wrong/missing, it's a little difficult to confidently move forward.

karl ruiter

I would not go that far in. These things can be a bastard to bleed. Maybe it was just that. If you are going to go in deeper I would NOT remove the master. Take it apart from inside the car and inspect the parts first. That is easy. Installation of the MC with the motor in is one of the most difficult tasks on these cars.

rockatansky

Thanks to all. I know I have work to do. To clear more things, I must say that I know that the reason of taking apart those parts (exhaust, bellhousing cover, etc) was the ball socket of the front guide rod at the gearshift. As you know is a pita to get the ball back in place without enough space. In the wsm they unmount central tube and reaar axis to get the ball out and set it correctly.

I think that the previous owner try it himself without success. He clear out space to work on it removing those parts (and thats the only reason of taking them apart I think), but finally he was not able to do it and sell the car. So I think that the car has been stopped for two years but apart from that it must be ok.

I have been able to get the gearshift working again installing a 'precission ball cup' from 928motorsports and a short shifter. It's very likely that the work left will be to replace all liquids and filters including trans oil, I have also to replace the expansion tank which has a crack and of course I will have to fix the clutch failure of pushing the pedal with the slave apart.

Next day I get to the car (probably this weekend), I will study the clutch system and see what I can learn of it. I promisse I will bring a collection of detailed photos and doubts about it...

rockatansky

Yesterday I have had the morning to go with the car. I print all your suggestions and went to check the slave for the first time. As you say, with the slave hanging and the pedal depressed, the fluid just went away, at least a big part (probably when bringing the car home on a truck). I see bubbles and some liquid droping from the slave.

I checked the clutch (no wire shims). Because the ball socket repair is already solved, I was able to put the bottom bellhousing cover back in at least with some screws, and the slave back in place with its two big screws to see how it goes.

Here are a pair of pictures with the slave in place:





With the bellhousing and slave tighten, probably the next thing I will try will be bleeding the system. Jim already explained the process in a previous post that I will try but I accept any advice from you on this task and then search for leaks. I see liquid must be SAE J 1703 or DOT3 from the 30 year old user manual. Also see that brakes and clutch are sharing this liquid from the same reservoir. Dont know if I should use the kind of pump as the one I see in the video in a previows post ( I have an unused one like this: http://www.928motorsports.com/parts/oilpump.php could be used?).

I also post a picture of the hole from the bottom, because I read in the wsm that it is used to check wear of clutch discs. With this picture maybe you have some opinion (my car is MY1980) (or not having in mind that the circuit still needs to be bleeded).

Also would like to comment the bad news from yesterday. When trying to loose the filling screw of the transmission oil, I have ruin it. I comment on it in a different post not to mix subjects, here is the post:

https://rennlist.com/forums/928-foru...h-picture.html

Thanks.

WallyP

There are two common recommendations for brake fluid, ATE in Gold and Blue, and Castrol LMA, but any good name brand DOT 3 or DOT 4 will do. Never use DOT 5 silicone fluid.

The ATE is more expensive, but is a good fluid and has the advantage of allowing you to see when old fluid is removed when doing a flush, since you can alternate between Blue and Gold. There is no real difference between the colors.

The Castrol LMA is a good fluid, and the LMA stands for Low Moisture Absorption, so this fluid will absorb less moisture between changes.

rockatansky

Hi, sorry for taking so much time to comment on this. This weekend I have had some time to keep on with the car and I would like to comment my updates.

Having in mind all you told me, I get the conclusion that the clutch pedal was pressed when the slave was not mounted forcing it to evacuate the clutch fluid. So, I start the process to feed the circuit and make it work. Everything was fine and now the circuit seems ok without leaks.

Here I describe what I did yesterday:

After repairing the front ball socket of the gear shift... there were a few things that need to be mounted apart of the clutch and brakes circuit to be bleeded.

- Prior 2 bolts of the clamping sleeve that connects the drive shaft near the bell housing (One is opposite to the other). One needs to be tighten with the bell housing cover out, and I suppose that the other should be tighten through a hole in the central tube but I will only have access to it if I turn the drive shaft 180 degrees.

I tighten the first (80nm) (the one inside the bell housing). Closed the Bell housing cover, set the slave cylinder with its two bolts. Bleed the clutch circuit with a motive power bleeder (removing all old fluid). Check the clutch pedal. Now the pedal seems to work great, I feel the pressure and it comes back by its own, perfectly.

Now here is my new problem. I thought that once I have the slave set, the circuit bleeded, the clutch pedal moving ok with pressure... then I will be able to press the pedal from inside the car and other person will be able to rotate the drive shaft through the central tube hole to be able to set the second bolt in by turning the drive shaft 180 degrees.

The problem is that when I press the pedal, the drive shaft keeps stuck and doesnt let me rotate it to set the second bolt. How should I do it?. Should the drive shaft get released when I press the clutch pedal?.

Here are a pair of pictures on location:





I will appreciate any comment on that, thanks!.

Landseer

Should be able to rotate driveshaft if car is in neutral, to an appropriate orientation, then slide forward the clamp.

Or, mate them and rotate engine clockwise (when facing car). Can be done with 27mm socket from under car.

If the clamp won't mate-up because its not on the same axis as the intermediate shaft, then you need to release clutch to get enough up/down/sideways movement in the intermediate shaft to make the alignment. I use a winch on the arm, with bellhousing removed.

rockatansky

Thanks Landseer, the car is in neutral, and I think it is with the proper orientation (I did some tasks on the gearshift some weeks ago). The gears change smooth so I think it's ok.

I already slide the clamp to connect both shafts, (I needed to try different angles until it slides to match both axis and also have a good position for the first bolt to be tighten). Also the axis on both shafts seems ok, because they mate perfectly when slinding the clamp.

But, the driveshaft wont rotate. I will have to try to rotate the engine as you said. Clockwise facing the car and with a 27mm socket, ok. Could you point me where to look for the 27mm socket for rotating the engine?. Thanks.

Landseer

Crank pulley bolt. Shouldn't be much resistance to rotate engine.

But you should get movement at the driveshaft before connecting.
Can you rotate tires when in gear and get driveshaft movement?

rockatansky

Right now I dont have the car near me to check. I can tell you that the car is now on 4 jackstands with the 4 wheels on the air and in neutral. As soon as I get to the car again I will check if the driveshaft moves when rotating the tires.

Landseer

You would put it in gear for that. Somebody might need to hold the other side wheel / rotate it forward also.

It may also be possible to disconnect the rear sliding coupler and check for easy rotation of driveshaft. However you approach it, check for sensible function back there before hookup to the engine.

rockatansky

Ok. yes I could also disconnect the rear coupler in the tests, I have access to it. Prior to the checks I will have to close the transmission case, because right now it has no fluid and the back cover of the transmision is removed as you can see in my other thread of today.

I had problems with the drain plugs that already has been solved. I'm waiting for the new gasket for the cover. As soon as I have it, I will fill it with new oil, and then I will be ready to check the driveshaft movement and how and when it moves. Thanks.

AO

+1 on the crank bolt. Double check to make sure the starter ring isn't binding on the sides of the upper bell-housing. If it's still locked up, try pulling all the spark plugs just in case you have fluid in one of the cylinders. Once free, I usually use a a small pry-bar on the teeth of the starter gear to turn the assembly.



Once you can get it to move,