so in the middle of diagnosing my clutch problems i have noticed that the clutch is engaging almost immediately when i tap on the clutch (there is no slack in the clutch whatsoever. It feels fully pumped up and the moment i tap on it the clutch disengages. I assume 1 of 2 things.


1. air possibly in my lines so i need to rebleed.

2. i need to adjust the clutch pedal.


I have taken out the bottom part of the dash and can see the two nuts (locking and unlocking on the clutch pedal. Is it as simple as readjusting these to give my clutch pedal a little slack?

That's a hydraulic clutch so there's no real adjustment to it - the fluid will simply fill up any space you create by adjusting it. However, there should be an adjustment for the length of the pedal shaft into the master cylinder and yours may be a tad too long. There should be just a bit of play between the end of the rod and the piston in the slave cylinder (I don't have a number but I did mine with maybe 1/16" or so) and it sounds like yours has no play. See if you can make a little clearance there.

A disclaimer - I'm using the S-10 clutch master and the Mercedes slave and made my Chevy mater cylinder linkage work on the Chevy master so yours may be REAL different. Still, the Chevy system is pretty common to almost all cars.

Dan

Is this the nut and locking nut next to the pedal under dash? Or is the pedal shafts adjustment somewhere else?

What is the history of the car?

Has the pedal always been high?

As the clutch wears the slave cylinder gets pushed farther and farther into the bore, this is the self adjusting portion of the clutch release system.

If the clutch disc is worn out you will get a high release pedal.

The adjusting nuts on the clutch master are a one time adjustment when the part is installed. If you can jiggle the pedal up and down by hand and the rod moves in and out, the adjustment is good.

I think so but it would help a lot if you could post a pic of it. I know it's kind of hard to get a shot under the dash but that way we can be sure we're all talking about the same thing.

Dan

great advice.. i will post a pic tomorrow.

one interesting thing. When i drive around for 10-20 minutes there is no slipping and although it does disengage very high... there are no major issues.

after about 15 minutes or so 4th gear starts to slip... 5 minutes later 3rd will start to slip. 2nd and first never slip.


but every day ... on a cold start.. in the morning... there is no slippage period.


could this be a sign of air bubbles in the lines.. or is the clutch disc just shot.

What you're describing is the classic symptom of a worn clutch.

http://s31.postimg.org/9xbw2uc6z/clutchmas.jpg

Why is the slipping symptom time dependent? Because with increased operating time the temperature of the fluid in the hydraulic system rises, and with increased temperature the volume of the fluid also increases. If, as may well be the case, the clutch master cylinder pushrod eccentric bolt at the pedal has been adjusted too tight, then the fluid return port in the master cylinder is blocked. In that case, the fluid cannot escape to the reservoir as it expands, but rather places enough force on the slave cylinder to release the clutch, hence the slipping.

In that,pic. It looks like that bolt is as loose as it goes. Or are you talking about a different bolt?

Again, I'm not very familiar with the Mercedes chassis but I wonder if someone put the wrong rod in there at some point in the car's past. I agree that it looks like the rod is as short as it can go which makes no sense.

Can you reach up and feel a bit of looseness between the rod and the master cylinder? Remember, there will be a spring to overcome to feel the slack. If so, that's not your problem.

Another thought - I wonder if the circlip in the end of the master cylinder is out of place or missing. It might be worthwhile to loosen the master cylinder retaining bolts/nuts (not sure on your car), pull the master away from the firewall, and look in the end of the master with a mirror and a light. There should be a groove and a circlip (internal snap ring of some sort) to keep the guts in place. If that's missing or not in the groove it could cause your symptoms. No guarantee on this notion!

Dan

ambush:

The pic which you supplied is of the overcenter spring, and its adjustment.
The clutch master cylinder pushrod adjustment is up at the top of the clutch pedal, and consists of an eccentric sleeve and a lock bolt for the sleeve.

The engagement point is pretty much at the top. If I tap on the pedal the clutch will disengage. Not sure which bolt to turn to lower the engagement point

To lower the engagement/disengagement point, loosen the lock bolt at the top of the clutch pedal, where the clutch master cylinder pushrod is connected to the pedal, and turn the eccentric sleeve until the pushrod has slack.

Frank knows this stuff!

Dan