rockatansky

Hi. I recently bought a 928 with a failure in the gearshift. I knew that the previous owner has been trying to fix the problem (an issue with the front ball cup) and the car came with the exhaust, gear lever, bottom clutch housing, taken apart, and the slave cylinder is also hanging under the car (I have it on jackstands).

Well, the thing is that since the car came in, the clutch pedal was in the fully depressed position. I suppose that this is some kind of trick to easy things when having to fix things in the gearshift system to avoid having to be pressing the clutch from inside the car while doing tasks under it, right?.

Now I have the ball cup fixed, gear lever mounted, the gear changes smoothly and I'm going to start mounting the clutch housing, slave cylinder, etc back in, and would like to ask you before what should I operate to release the clutch from the fully depressed position. Thanks a lot.

Dave928S

Sounds like you might have a failure of the hydraulics (or air in the system). The clutch assist spring will hold the pedal to the floor if you are not getting the clutch pressure plate pushing the pedal back up as well via the hydraulics.

It could also be that the previous owner has wire shims still in the clutch plate to hold it released, as you have installed when doing a clutch job.

As the PO was chasing the problem, it might also be that something has been left out.

rockatansky

Thank you Dave, I think it should be more the second thing you are saying. I'm almost sure that it is something he has done to keep the clutch pressed for clutch jobs, more than an hydraulics failure.

Wire shims?, where should look to see if that is what is keeping the clutch pressed?...

jon928se

The wire shims slot in the outside of the clutch pressure plate to hold the p plate in the disengaged position so you can remove the clutch assembly.

Look under the dashboard - head on brake pedal - look up at the top of the clutch pedal. You will see a spring that helps push the clutch pedal down. This is why your clutch pedal stays down. Disconnect this spring until you finish getting the clutch working properly then refer to the workshop manual for how to adjust the amount of spring assist properly.

Dave928S

Good idea to take the spring out of the picture ... it'll just make it more difficult to find the real problem.

Here's a pic (from Sharkskins clutch install write up) of one of the wire assembly shims fitted to a pressure plate. These are only used during clutch installation and are taken out once assembled. If you see these then that's what's holding your clutch released.

rockatansky

Ok, thanks both... I have been with the car this morning working with other things. The only thing I have tested with the pedal is to take it with the hand from the full forward position which it was originally and I have move it towards me.

The pedal moves easily and then keeps in the full back state... keeps there unless I puss it forward again with the foot to take it to the full depressed state and then it keeps there again.

Now that I have read your messages about the spring, next day I will take a look at the spring to disconnect it and avoid any interference with the real reason of not coming back by itself. I will let you know how it reacts... thanks.

Dave928S

That confirms hydraulics aren't working or pressure plate is stuck in the released position. If you're doing any hydraulic bleeding you'll get better feel of how you're going without the spring there ... and it's worth adjusting it anyway.

Apart from hydraulics and the shims, it's also possible that you have a major wear problem, and that the release bearing assembly has let go of the pressure plate fingers.
You'll need to take off the lower bellhousing section to clearly see what's going on with the pressure plate and release mechanism.

rockatansky

I dont have the car near me right now, but I can say that the lower bellhousing section was already removed when I get the car. Apart from the exhaust sections, the bottom bellhousing cover was in the rear trunk, so maybe they have been doing some job there that has left the pressure plate released or whatever.

I will check the wsm and take a look down there to see how it is now and how it should be on the bellhousing. Thanks a lot for your help Dave. I'm a newbie with cars (some months ago I dont even know how to change oil) but I'm learning a lot. With the help of the forum I have already been able to repair the gearshift and I'm pretty happy with the results!.

Dave928S

Post some pics of what you see if you can.

raidonzap

Here's a handy video for bleeding your clutch:

http://www.youtube.com/watch?v=wdf--suwqw0

karl ruiter

There is a return spring inside the master cylinder, which should return the pedal. It is possible for the spring to break, leaving the pedal at the floor. You can easily take the master apart to inspect the parts, just by removing the C clip.

Jim M.

I think all of you are missing this important point. With the slave hanging down the clutch pedal should never be depressed! What you have done is extend the slave beyound the normal travel, possibly damaging the seals and creating a hydraulic leak. Inspect the clutch for the wire spacers or the 3mm angle shims (you don't say what year the car is, the later clutches use a angle shim instead of the wire) and remove them. Re-attach the slave cylinder and bleed the system. If clutch operation appears normal after bleeding then inspect the slave to check for leaks.

Some pictures and the year of your car will help us troubleshoot for you.

rockatansky

The overall picture is getting more clear. I still need to see the car and take a close look about the clutch problem. Jim says that with the slave hanging the pedal should not be depressed. Now I'm thinking that he could be right and that this could have been the problem. I still havent been able to see the car (is in my brothers home) and check the points you all are saying, but I have here two older pictures in my computer of the bottom of the car (very bad pictures by the way) where you can see that the slave cylinder in there hanging and also the bellhousing cover removed, not much more, but this pictures were made some weeks ago and not for this purpose.

Thats is how the car was delivered at my location from a different city, carried by a truck with a car transport company. Now I think that it is possible that the person that bring the truck with the car on, could have pressed the clutch when doing the loading operation. Did not know why the previous owner didnt advice him about the slave and not pressing the clutch.

In the pictures at least you can see that the slave cyl is hanging, not much more. In any case, as soon as I get to the car, maybe this next weekend I will be able to make some high quality (and sharpen) pictures of this zone and start thinking about how the clutch system works and how to repair, bleed the clutch, study the wsm, etc.

As said, I forgot to mention the car MY. I'ts a 1980 5 speed euro 928.





Thanks for your comments and also for the video of bleeding the circuit. I think I will need it in the near future.

Landseer

Looks like you have some work to do, but hey, they all need something.

The clutch pedal will indeed cross a spring detent and go straight to the floor and be lightly held there... if the system is not bled or the master cylinder piston is degraded.

(when i'm under the car bleeding it and an assistant pushes the clutch on-command, it always jumps down away from their foot and slams the floor and they always apologize)

Take your time, work through it.

Jim M.

Okay as an 83 it will use the wire method to hold the clutch in the released position. However, what I said still stands as far as the slave cylinder. 1st. Inspect the clutch pressure plate and make sure the wire spacers are removed. You will need to turn the flywheel with a screwdriver or pry bar to inspect all three locations. (Turn the engine in the normal direction of operation only! Pry from the LH side of the bellhousing.) Once the wire spacers are removed re-install the slave cylinder and bleed the system. if you have a power bleeder then open the bleed port and with the system pressurized depress the clutch several times. That will usually bleed the master and slave cylinders of any air. Without a power bleeder you will need a helper to depress the clutch each time you open the bleed port. Then close the bleed and have the helper pull up the clutch until it returns to the top position on its own, and when you stop getting air out the port. Then inspect the slave for any leaks. You may have to remove the slave again to make sure fluid is not bypassing the seals and leaking out by the push rod. If you have a leak, replace the slave and bleed all over again.