Clutch Master Cylinder Rod Adjustment - PeachParts Mercedes-Benz Forum

charmalu · #1 04-21-2009, 02:39 PM

This question is for those of you that have a cluch in a 240D or 300D, and have actually done this adjustment and or replacement.

The rod that goes into the master cylinder has a bolt and a bushing that is an excentric for the adjustment so there is some slack when the clutch peddle is released. This is so no pressure is applied to the MC, Slave and the release (Throw out) bearing.

I had some slack in the peddle when I first got this all connected. I have a little over 700 miles on it since the conversion, and now the peddle is tight.
Yes I finally converted the 85 to a stick.

The bolt I can turn, the bushing has flats for a wrench also. how do I turn the bolt and hold the bushing from turning while tightening the bolt. there does not seem to be any room for 2 wrenches, and also looks like maybe one or both might have to be ground down to fit. still don`t see anyway to get 2 wrenches and both hands and a light to see, and get this adjusted. maybe just dumb luck.

Looks like I need to be either a midget or a contortionist to get up under the dash.

The original MC which was attached to the peddle assembly I removed from the 83 240D at PNP had the white plastic end on the rod.
The new MC came with 2 rods, a white and a black plastic end. the black being the longer one or the 2, I used the white one to stay the same as the original. I did order the correct MC for the vin series.

Charlie

winmutt · #2 04-21-2009, 03:16 PM

I think you move the pedal to adjust the eccentric. I find that putting myself in the car upside down is the best way to get in there.

chetwesley · #3 04-21-2009, 05:07 PM

I am interested in knowing the same thing as I will be doing the MC replacement on my '79 240D this weekend. My MC came with the two ends as well.

Also, what is the difference between the MC in the older and later vin #s? I ordered according to the year and model of my car and was presented with only one option.

charmalu · #4 04-21-2009, 08:48 PM

I looked in fast lane and there is only one option for 79 240D. most likely it is the one for the early model with the iron box.

All parts Express shows two MC, one for the early , and one for the later aluminium box. depends on your Vin.

check the length of the rod you now use, and use that one or the same length new one.

Charlie

chetwesley · #5 04-22-2009, 08:07 PM

I ordered mine from another parts supplier which only gave one part number, regardless of the year (I checked back for different years 78-83 -- all the same part). It didn't specify anything about the vin, though comparing with APE, the one I got is the one specified there for the later VIN numbers.

When I look at the two MCs on All Parts Express the older and newer versions look the same other than the color -- so what is the difference other than color of the cyl itself?

If I compare the one I got with the one in the car and it mounts the same, am I good to go with it, or is there some internal difference?

I will check against the VIN when I get home, but I am just wondering what the difference is, if I got the wrong one, because I don't want to go through the hassle of returning and waiting for a new part to come if there isn't any difference.

Also has me wondering about the slave - I would guess there would be two options for that as well, but I wasn't presented with an option when I ordered it. Everything fit when I installed it and it looked the same as the old one as far as I could tell - anything to worry about there?

charmalu · #6 04-22-2009, 10:55 PM

Yeah the slave, Mc and throw out bearing are different between the iron box and aluminium box.

Seeee, ya should buy from Phill, and you get options

.

Charlie

chetwesley · #7 04-23-2009, 02:22 AM

Is it possible to actually bolt the wrong one in? (I am thinking particularly of the slave, which is already in).

Also, I can't seem to decode how you know which MC to get - APE gives you a seven digit number starting with a letter, but my vin has no letters in it - no idea if it is before or after the numbers they indicate.

The slave listing has a six digit number, no letters. I assume you use the last six digits of your vin. I am pretty sure I got the right slave.

charmalu · #8 04-23-2009, 03:00 AM

Iam not sure of the difference between the parts, as I haven`t seen them side by side. might be the slave has a longer throw on one of them.

I have both t/o bearings, and there is a difference.

I didn`t understand the numbers either, so I called phill when I orderd parts. I have the VIN plate off the 240, and I don`t see how the # connect.

Charlie

chetwesley · #9 04-23-2009, 03:28 AM

Yea, I sent Phil an email to find out. The listing of parts seems to suggest with the MC that you can use the silver Lucas one with the correct length rod (the white one) in place of the black one for the older models... but those notes under the parts are pretty cryptic for a lay person such as myself.

I am pretty sure I put my old slave and the replacement side by side and they looked the same. I also read something though in an old post about someone opening up two slaves and finding that one had a spring inside and one didn't... I wonder if that has anything to do with the differences.

mwoodland · #10 05-01-2009, 04:19 PM

Getting back to one of the original questions: the eccentric adjustment on the clutch pedal arm is locked by a bolt. you can back out the bolt several turns until a wrench will fit on the flats of the eccentric nut.
Turn the nut to see the clutch pedal rise, i.e. come out further from the firewall. Adjust to suit, and lock down the locking bolt.
I just did mine last week (not that it helped.. I still need a new clutch disk..) so the details are still fresh.