Petza914

On the 81 Euro 5-speed I bought, a few weeks ago I replaced all the hydraulics - clutch master, clutch slave, brake master, brake booster. I've been driving the car around for a few weeks (500 miles) and it has been fine except when up shifting or downshifting into 2nd or 3rd, the gears catch a bit unless I double clutch. Doesn't do this in 4th or 5th so might be synchro, but figured I'd try to improve it.

So I planned to take the clutch out today to grease the spline shaft, install a new guide tube, and install a new ball cup on the pivot arm.

Well, with the MSDS headers that are on this car, there is no way to get the lower bell housing free, and didn't want to remove a header since that's a pain and I don't have new gaskets to reinstall it.

I was able to get enough working room between the upper and lower bell housings to move the torque arm off the ball cup and install the new ball cup. Figured that might help. The other one either fell off when I pressed on the torque arm or wasn't there at all.

Put everything back together and now the clutch won't disengage enough to allow the car to shift into reverse. I've played with the adjustment of the threaded rod and I can make it worse but can't make it better.

When I push the clutch in the pedal does not go all the way to the floor. It feels like it hits some type of metal internal stop, maybe in the clutch master?

Why did replacing the ball cup make the clutch operation worse to where the car isn't driveable now? Why does the pedal hit some type of stop and not go to the floor and how do I fix this?

Anything else I should look at?

I even did the slave bleed where you compress the rod in and hold it for 20 seconds a few times before reinstalling it. The clutch action feels fine and I didn't open the hydraulics at all.

I get about 13mm of slave rod travel when the clutch is depressed?

This is all the space I had to work with at the bell housing.






Shut it off to get it into reverse and drove it around the neighborhood. The clutch isn't fully disengaging. I can feel it dragging when in first with it fully depressed and it engages right off the floor, which isn't really off the floor, it's off whatever that other stop that's happening is. If I lengthen the threaded rod it just makes that same stop happen just further from the floor. If I shorten the threaded rod, it won't do into any gears without grinding or not at all because it's now not pushing the clutch as far.

This is what the arm with the new ball cup looks like.

Silver79

I would probably start by checking the new clutch master cylinder piston length and new slave cylinder push rod lengths. There has been discussion on here before that some of the replacement parts have different lengths than the originals and cause clutch release problems.

Petza914

Info I've received so far is that the new masters have some kind of stop on the piston that has to be removed and the piston also has to be shortened 4-5mm. Can anyone confirm this to be the case? Sure wish I knew about this before installing the new master as it would have been much cleaner and easier to do this before it was full of fluid and installed in the car.

Now it's going to be a messy job to remove and modify the piston from the MC with it installed behind the brake booster, and I don't want to remove that again.

What's weird is that it worked better before I installed the ball cup that's supposed to be there.

Lizard928

If the H adjusters are set the stop on the master piston does not have to be removed.

Petza914

You're talking about the H adjusters on the clutch plate assembly itself? Can't get to that without at least removing one header.

The other thing I turned was the wing nut for the spring. That's doesn't do anything but change the amount of pedal assist, does it? Could it shorten the stroke somehow? The spring is not closing up during the pedal movement.

Mrmerlin

I would check that the push rod is inserted into the release arm
NOTE remove the slave and do the bleed procedure again

Petza914

I checked it when trying to troubleshoot it earlier today, but will look again. Also, easy enough to remove the slave and do the push and hold bleed procedure again. When adjusting the threaded rod from the pedal to the master, what I've read said to remove the clip the holds it to the pin and adjust it's length so it slides easily onto the pin, but with zero play, then take 1/2-1 turn off of it (shortening the rod length) and that should be the proper setting. Do you agree?

Does adjusting the wing nut for the helper spring effect the available pedal travel at all. That's the only other thing I played with today, as the WSM said there should be 43mm of space from the end of the spring plate to the center of the pin on the older cars, but that distance is reduced to 21mm on the newer cars. If all the new clutch masters are really the newer car style, should I reset the wingnut to achieve 21 mm of clearance and will that have any effect on the problem I'm currently having?

belgiumbarry

i don't understand why the new ball cup makes a difference.... if there was none . Now the release arm is a tiny bit ( thickness cup ) more away from the pressure plate , so it should even work better ...

I assume the slave rod has to be at max length possible so that the piston is all the way pushed in . That provides the full working travel when pedal pushed , as long of course there is enough oil pressed in it coming from the master. Easy to see how far you must push the slave against "oil returning reservoir " till you reach the mounting position on the bell housing. I measured it compared with slave travel itself to set it at nearly max . Not more of course , then we should already be pressing the release arm and risk the clutch soon to fail .

Petza914

I don't either. Lengthening the threaded rod to the master doesn't get me any more slave travel: it just makes the clutch pedal artificially bottom out higher up (farther from the floor). I have to push on the slave when installing it so the slave has pressure throughout its stroke and is essentially preloaded like it's supposed to be. I will try rebleeding as Stan suggests, but am skeptical it will get me anywhere as I have resistance in the slave through the full range of travel and didn't open any hydraulics during yesterday's work.

Would unscrewing the pivot ball a couple turns accomplish anything. That would angle the bottom of the torque arm more toward the slave or is that only threaded so it's replaceable and not as an adjustment point. Though that should accomplish a similar thing to install the ball cup, which actually made it worse.

belgiumbarry

no... pivot ball has a very short thread, only to fasten.
I think you don't get enough oil to the slave .... you have a new MC ? doesn't this need a mod at the piston ? ( shortening to have more travel = more oil )

Petza914

That's exactly what I think the problem is. Wish I knew about this before installing it as it would have been much cleaner and easier to do this when it was new and not in the car behind the brake booster. The part I don't quite understand is why it's worse than it was now.

honerboys

i really can't remember, but you might be able to pull the clutch master piston out from the cylinder from the interior of the car - seems like i did this once - you'd have to catch the fluid in something under dash - open slave bleed and pump clutch to get as much fluid out as possible - reservoir will only empty so much so brakes will not be affected - others can chime in as to whether this is possible - it would be way easier than pulling brake booster

honerboys

check out post #20 here
https://rennlist.com/forums/928-foru...old-one-2.html

olmann

Correct. You pull the rod off the pedal and remove the boot. Then there is a cir-clip that is easily removed allowing you to pull the piston and spring.

Petza914

Yep, this will be my plan tomorrow if bleeding does nothing.

I think I read that in addition to the piece on the new slave piston being removed that the rod also has to be shortened 4-5mm. True?