I'm helping a friend with his manual transmission 79 300D. The clutch pedal went soft a few days ago. The fluid reservoir was very low. I refilled it which didn't fix the problem, so at the very least the clutch needs to be bled.

I've looked for leaks around the master and slave cylinder and haven't found anything obvious, however there is brake fluid dripping off of the bottom of the transmission bell housing. The drip accelerates if I pump the brake pedal.

Is there any hose or brake line around the top of the transmission I should be looking for?

The line from the master clutch cylinder to the slave cylinder on the side of the bell housing.

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1979 240D Caledonia Green/cream gone
1982 240D stick Ivory/Palimino
1999 E300D White/grey

There is a rod in the end of the Slave cylinder that pushes against the throw out bearing lever.
the seal around the rod is leaking, that is why you see fluid leaking from the bottom of the tranmission.

You will need to replace the Slave cylinder.

It has been recommended that is the slave is replaced, the master cylinder will go next, (Vice versa) so do them both now, and save a headache later having to go back in again.

Here is a good video showing how it all works, and bleeding procedure.
He says BMW, but the mercedes is exactly the same.
http://www.youtube.com/watch?v=wdf--suwqw0


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

X2 on the diagnosis and repair. Like Charlie said, the fluid coming out of the bell housing weep hole is from the failing salve cylinder seal.

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'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
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"Back off, man. I’m a scientist” ~ Peter Venkman

Cool, thanks for the feedback. Has there been a good write-up done on replacing the slave cylinder? I've done some searching but haven't found anything yet.

Not sure if there is a dedicated step-by-step DIY, but check out post #2 in this link:

http://www.peachparts.com/shopforum/showthread.php?t=299032&highlight=slave+cylinder

Charmalu gives most of the details and provides a link on bleeding the system.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

Thanks again for the input. Replacing the slave cylinder seems to have resolved the issue.