BMW Clutch Issue

Scott Dorsey · 2007-06-15T01:56:59+00:00

1986 BMW 535i. I bought it a few years ago with a bad transmission and only120k miles, and a friend of mine dropped an '83 junkyard transmission into itand a new clutch. It's been running well, and I have slowly been cleaning various things on it up.Starting around 220,000 miles, the clutch began sticking closed. That is,I'd put my foot down, the pedal would stick to the ground, and the clutchwould remain engaged. I could pull the pedal up and pump it down a coupletimes and the clutch would open properly again. It started happening nowand then, and then more and more often.I replaced the plunger on the clutch master cylinder, which was leaking,on the suspicion the seal in it was bad. Didn't fix anything. Took itto a respected BMW indy mechanic around here, who swore I did it wrong andreplaced the plunger again. Didn't fix anything. Replaced the whole mastercylinder. Didn't do anything. Changed the fluid and replaced the slavecylinder. Still no go. Now, I am assuming that there is no possibility of the line between thetwo cylinders being an issue, and no backflow valve anywhere in the system.Is this correct?Recently it got worse, and I took it in to him again. At this point, wefigure it has to be something inside the transmission. He drops it, andreplaces everything that looks even a bit suspicious, namely the throwoutbearing release lever, the lever pin, the clutch release bearing, andthe shift bushings. Everything else looks clean, though neither one of uscould see how any one of these would cause the problem.Putting the thing back together, the problem is now actually worse, sincethe friction point is closer to the floor than it was before. The car isnow doing it almost all the time, making it impossible to drive except onthe highway.Help! Anybody have any suggestions about what could be causing this issue?--scott

Jun 15, 2007 20 Replies

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Scott Dorsey 19 years ago

This is a good call! The original one in the car had cracked and been welded. I replaced it with a junkyard one, and it didn't fix anything but it WAS a good suggestion.

Last weekend I replaced the hose going from the reservoir to the master cylinder, drained and pressure-bled the system. Didn't do any good at all but the original hose was a little grotty.

Next weekend the project is going to be to change the hose and pipe between the master and slave cylinders, JUST so I can say I have replaced everything.

--scott

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