Clutch disengagement and "what is on this car?"

#1

So bought a SE30, and trying to iron out a few things, i’m hoping you guys can help…

Problem: The clutch disengages when the pedal is just about to hit the floor. The engine is a newer street rebuild with no track weekends, and the clutch had 3 weekends on it. The tranny is original. The previous owner replaced the MC, lines, and slave to try to remedy the issue. Personally, I hate this and much rather it be up towards the top. My old honda was like this (ACT clutch) and it was perfect for me.

What I’ve done. I spent the past 2 hours researching this issue, and learned a bunch. With the help of my pops (40 yrs mech. xp) we’re going to bleed the lines and see what that does. however, looking at this car, some things stood out to me.

The slave cylinder has the bleeder screw pointing down, which means the engineer that designed it is standing on his head, please call 911 before he hurts himself. (i tried to attach pic #1) But seriously, on a quick search it looks like that’s how all the replacements are, except for here… http://www.realoem.com/bmw/showparts.do?model=1413&mospid=47322&btnr=21_0004&hg=21&fg=10 , which i pulled from my VIN number.

Now, that picture says my line goes to a dedicated clutch reservoir, which i didn’t see earlier. So I go out to the car, and see that there’s a line which goes to the brake reservoir. well, that seems cheap but ok. but i notice, there’s no hose clamp on the reservoir end of the line. (i tried to attach pic #2).

Does everyone have the slave cylinder bleeder screw pointing down? Shouldn’t there be a hose clamp on the clutch MC line to the brake fluid reservoir?

I’ve thought of ways to fix/adjust the issue though i doubt they are legal per the rules. 1) MC with bigger piston bore 2) slave cylinder and or flex hose with smaller bore 3) extend slave push rod (seen in another thread, but may increase wear/heat on the TOB, and will most likely only move the clutch disengagement point on the pedal slightly.

Bask me with your wisdom :slight_smile:

#2

well, i can’t attach pics for some reason.

pic #1

pic #2

#3

That blue line that goes to the fluid reservoir doesn’t come with a hose clamp on it from the factory. I also find that strange, but it is the same line on 944s and they don’t have a hose clamp on it either (just replaced master and slave in a friend’s 944). I added a hose clamp to mine to make sure it wouldn’t come off. I don’t remember if my bleeder screw was on the top or the bottom, but I remember keeping the bleeder closed and making the air bubbles go up through the system into the reservoir to bleed the clutch.

#4

10$ for a Sachs slave on rockauto. That’s what I’ve got. Its too cheap not to replace.

http://www.rockauto.com/

#5

Yes, bleeder screws point down. No, there’s no clamp on the reservoir. Seems strange to me too. Along with the new clutch, do you know the status of the throwout bearing, pivot bushing, and throwout arm? Excessive wear on any of these components will have an effect on the engagement point.

#6

If replacing the slave does not cure the problem, you probably need to replace the plastic pivot for the clutch arm. They will wear down and it takes more travel of the pedal to disengage the clutch. BTW, trans has to come out for that:sick:

#7

The bleed screw points down, but the drilling in the slave takes fluid/air from the top.

The causes of a low engage/disengage point can be a worn pivot pin, a failing master cylinder, or a worn clutch disk.

#8

thanks for the replies guys.

i hope to bleed it this week sometime. on my old honda we bleed the clutch line by pushing fluid back up to the reservoir from the slave, and we’ll try the same on this one.

i need to contact the previous owner, and see what exactly what all is new and used down there.

#9

Pushing fluid up isn’t going to do it unless you undo the slave and orient it such that the feeder line is clearly the highest point. Then I’d tap it a bit while you push fluid up.

Some folks successfully bleed the slave by allowing it to drip a little for several hours. That’s never worked for me.

My slave bleeder method, after burning thru multiple quarts of brake fluid night after night trying to make this goddamned process work on several occasions, is to undo the slave and invert it so the bleed nipple is highest. Then you have to hold the piston rod in with a C clamp or a clutch slave fixture (best). Then put your wife/mistress/girlfriend on the clutch pedal and with you on the slave nipple, do a standard 2 person brake bleed. Since you are holding the slave such that the bleed nipple is highest, the clutch pedal action will push the air out the nipple.

#10

My simple solution, which has worked every time, is to push ~250cc through the system with a pressure bleeder. I do a couple of full pumps on the pedal to disturb and flush out any air during the bleed.

#11

well we pressure bled the clutch line from the slave up. it definitely improved it, but it’s still a touch low for my tastes. however, i can actually feather the clutch now which is a good thing. it just feels so different than my e36. we’ll see how i like it this upcoming weekend.