clutch slave cylinder

[jmbour]

My 1971 280 SL has suffered for some time from the classical clutch symptom : the clutch pedal not returning fully up back . Instead of improving with use, it has become worse : now the clutch does not engage enough to change gears.

First, I tried to bleed the system, but it did not work (even with a lot of pressure, nothing getting out of the bleeders), so, after consulting the usefull information posted on this forum, I decided to repair the cylinders, starting with the master one . There where different types of master cylinders installed on 280 SL, and it is difficult to identify the good one, and in particular, the good repair kit.

I found that Neimoeller in Germany (www.neimoeller.de") can provide repair kits, but I could not find which, among three different ones,  is the good one.

In fact, I found that there are two main seals on the piston of my old cylinder, as the kits offered by Neimoeller contain more than that.
Is there a third seal at the top of the piston, behind the "cap" which holds the small spring ?, and how could it be replaced (see pictures attached) ?

I would appreciate some advice from those of you who have got through the same process .

Regards,

J.M.  Bour

[badali]

Is the seal flexible enough to strecth over the piston?  If the top is not removable this may be what you have to do.

[ja17]

The cap on the end behind the spring is a check valve. It is not normally replaced or  included in most  seal kits. Most likely your seal kit contains the two hydraulic  cup seals and the rubber bellows dust cover for the end.

Yes the seal will stretch over the piston. Lube it up with a little brake fluid and you can use a smooth round screwdriver shaft to help you ease it on.

[jmbour]

Thank for all the information.

I understand that I have to replace the two piston seals (I had to tear off the old ones, but I think the new ones are flexible enough to be streteched over the piston, with some care)..

 I will leave the check valve as is, and also change the dust cover, but I don't understand what is the use of the fourth part (on the right of the picture) in the kit offered by Neimoeller.

Thanks

[badali]

Is it a cap for a bleeder?

[ja17]

Hello,

Yes, most likely the cap of the bleeder.

[jmbour]

There seems to be a rubber in this cap, and it is worn.
Do I have to change it, and how ?
J.M.  Bour

[jmbour]

You are right, it should be a bleeder cap.

And, of course, I was speaking about the master cylinder.

J.M.  Bour

[114015]

Clutch hose,

ganz wichtig (très impotante)!
Check that one as well, or better, replace it. About € 35.00.

000 295 0835 Schlauch, Rohrleitung zum Nehmerzylinder, Hose, 250SL, 280SL
000 295 0335 Schlauch, Rohrleitung zum Nehmerzylinder, Hose, 230SL
 

IMHO

Achim