Hi guys
I have a 1975 230.4

THe clutch pedals goes in ... then slowly comes Bak out

I changed the slave and master cyclinders

Bleed it so many times already.....

I could get it to rebound normally a few times but then it went Bak to rebound slowly again

I m lost to what could be wrong

Can someone help ?

First. Peak under the boot on the master. Has the car lost brake fluid?

There are two rubber lines that commonly fail. The first is the supply line to master. It goes from the brake reservoir to master. It's not high pressure and just slip fittings. I used auto Tammy cooler hose, 8mm ID.

The second is between master and slave, left side of tranny. Only I could only find it at oreillys.

There's an adjustment for the return spring. It's in the FSM but not in my electronic index. I was gonna find it today. Prob not your problem but maybe make its not broke.

The worst case is that the springs in your pressure plate have gotten weak. This would mean pulling the transmission and redoing the clutch and pressure plate.

But I do think you should follow Lucas advice and look for leaking fluid from the hoses. It only takes a tiny leak to produce the problem you are having.

Leak under the boot of the master. The actual seals of the unit itself.

How would the springs in the pressure plate effect the pedal? What do they do actually?

They push the throw out bearing back while it whirls in the the bearing yoke. But when they fail they fail, they don't sometimes push back and sometimes not. They just get weak and your clutch will not return at all.

[QUOTE=Lucas;3441501]First. Peak under the boot on the master. Has the car lost brake fluid?

There are two rubber lines that commonly fail. The first is the supply line to master. It goes from the brake reservoir to master. It's not high pressure and just slip fittings. I used auto Tammy cooler hose, 8mm ID.

The second is between master and slave, left side of tranny. Only I could only find it at oreillys.
>>>>>>>>>

Can you tell me what part number you used for the rubber hose at OReilly's? Tried to look it up there and they found nothing. Found a hose at another parts house but it uses M10 x 1.0 fittings and the fittings on our 220 are M12 x 1.0.

I will look at my receipts later. Hopefully on there. If not it's listed on fcp euro but not available. It was like $45 but it was at the end of my project so I didn't mind.

It isn't on their normal system. They have a specialty place they order from. You have to pay shipping. I can ask the man also.

If you mean the slip fitting from master to reservoir, I just walked in the back and picked it out.

My son and I had exactly the same issue with our barn find 220. Tonight we finished replacing the rubber hose. I couldn't find one with the correct M12 x 1.0 fittings and the local shop I use for such things had no fittings to make a hose. So we used one from a early 80s Civic, correct length but M10 x 1.0 female fittings. We had to cut the steel line from the slave where it met the rubber hose as it was trashed. So kid learned the fine art of flaring tubing and we made up new steel lines with M10 fittings on one end and M12 on the other ends. Clutch pedal action is fine now.

The old rubber hose was check valving and not letting pressure bleed back properly. Common problem for brakes too. Used the bleed off the right front caliper method mentioned in the service manual...that worked great. One hour to fab and install new lines plus rebuild slave cylinder. I learned a new trick with the brakes to bleed clutch and Jackson learned a bunch of things.

We might even drive it to cars and coffee in the morning.

I just looked on Ebay today and the W115 clutch hoses are available again--anybody who hasn't replaced theirs yet should stock up while this batch is still around:
mercedes 220d clutch hose | eBay