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Discussion Starter #1
I've got a 4-speed 1980 240D that has a bit of the brake woes. Brake fluid is leaking out under the dash and dripping down onto the clutch pedal. It's been going on for a couple weeks. I don't think I can locate the leak, at least so far I can't, without pulling out the entire dash. Even then, I'm afraid once I go through all that the leak may be coming from behind the firewall.

This one has got me completely perplexed guys, any ideas or knowledge on what to do would be greatly appreciated. Obviously I'm trying to knock this one out myself. I've had this car for over a year now and have so far done all the work myself. Taking it in to the mechanic would be tantamount to admitting defeat!
 

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My first off the hip guess w/o my books right in front of me is to check the back of the m...

My first off the hip guess w/o my books right in front of me is to check the back of the mastercylinder/powerbooster. That's in the right spot @ the firewall to leak in that area. I'll get my books out later and look. Something similar happened to my 1969 lincoln when i blew up both the mastercylinder and power booster @once on it, but I've never had that problem with a benz.
Good luck.
 

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Maybe your clutch master cylinder is leaking? You should be able to look up along the leng...

Maybe your clutch master cylinder is leaking? You should be able to look up along the length of the pedal or at least feel where the fluid is coming from. Have you checked the brake fluid level in your reservoir?

It is a pretty simple fix, albeit a bit difficult to get underneath the dash etc...
 

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Definitely the brakes

The brake reservoir needs to be topped off about once every two weeks as it stands now. The clutch reservoir has been holding steady. I replaced the slave cylinder on the clutch shortly after buying the car and have had no trouble with the clutch since then. Every once in a while the brake pedal will go all the way to the floor, and if I pump it real quick it will regain braking power/pressure. I drive like an old man, real slow and with lots of room, and I typically don't go very far so the problem has been manageable for a little while now. I don't think she's going to hold out much longer before something just snaps.

My feeling is that it is probably the master cylinder after looking that up again in my own repair manual. Typically, I don't give too much info at first since I appreciate the critical thinking of others when they have only the minimum of info to go on. Keeps my assumptions from influencing their thoughts.
 

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I think you are right, the master may be leaking as it sounds like you have some air in th...

I think you are right, the master may be leaking as it sounds like you have some air in the system. Although, I would assume that once you have air in the system, the system would act the same(ie squishy brake pedal) all the time.

If you can wrangle your body into position you should be able to see if the brake fluid is dripping from the brake pushrod or the rubber boot.

My Haynes manual shows the clutch fluid reservoir and the brake fluid reservoir to be the same thing. Is this the case for you?

The manual also states that you should bleed the clutch system with pressure from the slave cylinder. That is the first time I have seen it suggested to bleed the clutch in that manner. I would guess that most people do not have a pressure bleeder.
 

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The brake and clutch reservoirs are in the same little housing, but they have a little baf...

The brake and clutch reservoirs are in the same little housing, but they have a little baffle in the middle that keeps the fluid separate. That way if you're leaking out of one system it becomes obvious.

When I replaced the slave cylinder on the clutch we bled the system in a decidedly different manner than was described in the Haynes manual. We ran a hose to the nib on the slave and pumped fluid from there to the top of the reservoir using a basic hand pump. Takes more elbow-grease, but is far less complicated. Of course, it requires two sets of eyes to do.

At this point I have stopping power, but if I hold my foot down on the brake pedal with a great deal of pressure it will eventually go all the way down. I presume that qualifies as "squishy." If I was the kind of driver who waits until the last second to stomp on the brakes I would have crashed weeks ago.

I'll try to squeeze back up under the dash again today, but so far those attempts have been pretty lame.
 
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