Car is 1975 240D. Recently I was going to work in the morning and found that my clutch pedal went down to the floor, no resistance. It does not return. It drove fine before that. I jacked up the car and saw lots of brake fluid around slave cylinder. Master cylinder is dry, as are hoses and lines that I can see.

Today I replaced slave cylinder and bled using the front right brake caliper method. Pumped until there were no bubbles. Clutch is the same as before, goes to the floor and does not return. Before I take everything apart again, does anybody have any suggestions?

Thank you

You will find its the slave cylinder on the bell housing You have 2 cylinders best to do them both at the same time .Hope this helps you .

Try adjusting the push rod so that there is no slack and it is putting pressure on the fork.
you should be able to get a pedal then. After it is completely bled adjust the rod back to specs.

I've had trouble bleeding those hydraulic clutches. I would recommend trying a vacuum or pressure bleeder set-up.

Just did another one today. I've tried pressure bleeding the clutch in the past with not much luck. In 47 years of doing this I have found that adjusting the push rod overtight is the most consistently successful method. You need someone in the car pumping the pedal. He/she will need a rope or something to pull the pedal up every time you bleed the slave because it will go to the floor and not return. Make sure all of the slack is out of the fork with the spring off. Reinstall the spring before starting to bleed.

kk: Were you able to feel the slave push-rod in contact with the socket of the release arm?

dd: The slave push-rod is 1) completely enclosed in the bell housing, and 2) does not have provision for adjustment of length.
The clutch master cyl. push-rod must be adjusted so that there is a small amount of clearance to the piston, otherwise the inlet port from the reservoir will be blocked.

There is no return spring as with most older US made cars. The MB system is designed to operate with zero clearance between release bearing and clutch fingers. An internal spring in the slave cylinder keeps the push-rod against the release arm.

Thank you for all the replies. I'm happy to see forums that are still active.

So the push rod I should be adjusting is on the master cylinder? I can't quite tell based on the replies. Is the way to adjust the MC obvious when looking at it?

I'll have a couple hours free to work on it tomorrow and will report back.

Since the clutch system was operating correctly until the time of abrupt failure, and if the clutch master cylinder push-rod has not been touched, and since you observed bubbles in the reservoir when bleeding, it is very likely that the MC adjustment is correct. And no, the adjustment procedure is not obvious.

Back to the first question: Could you feel the slave push-rod engage the release arm as you installed the new slave cylinder?

Ah sorry forgot to answer this one and it's important. The slave cylinder was difficult to mount because of all the resistance I was getting from inside the bellhousing. So the answer is, I am not sure. Should it have been relatively easy? or made a satisfying clicking sound or something?

Thank you

Forget everything I have posted. Major brain cramp. Of course Frank is correct. I was in 108 mode. Sorry.

Also I forgot to clarify, the transmission is still disengaged when the clutch pedal is on the floor. Thanks

The transmission gears are engaged/disengaged by moving the shift lever.

The clutch is engaged/disengaged by moving the clutch pedal.

To this point the thread has been about the clutch.

Something else?

I was clarifying because maybe it could be thought that the clutch was stuck engaged, which it is not. When users asked whether or not the slave push rod was engaging properly with the release arm, I thought I'd clarify that. Maybe it was a dumb thing to clarify though, sorry for the confusion.

Returning to an earlier post, should the next step be to unbolt the slave and try to make sure the push rod engages properly with the release arm?

If the clutch is not "stuck engaged", then for one reason or another, it is dis-engaged, that is, it is not capable of transmitting power from the engine.

indeed.

Back to this, would this have been an obvious click or something along those lines? I could not feel or hear anything specific, so it is possible I bolted it up improperly. It seemed like the only way at the time, it was difficult to bolt up.

thanks!