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Oops, bled clutch incorrectly, now what?

Discussion in 'E39 (1997-2003)' started by bobyang, Jun 22, 2008.

    bobyang guest

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    I have an e39 2002 525i and just flushed my brake fluid. As part of that, I figured I'd bled the clutch as well. What I didn't realize is that the clutch portion of the reservoir is separate from the brake side, so I didn't check the fluid level properly and drained the reservoir.

    Oops, lots of air in the system and no clutch resistance. Realizing my mistake, I refilled reservoir and rebled, but after pumping through a quarter of liter of fluid, the slave nipple is not passing any more air , but I still dont have full resistance on the clutch pedal, it engages near the bottom.

    Any suggestions?
    • Member


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    1. If you were pumping the pedal (instead of smoothly depressing it a minimum of times) you may have popped a seal or two. Any signs of leaking?

    2. Master cylinder/ Slave cylinder -- YOu could have a faulty slave cylinder, which is a snap to replace. Or, you could have a abd master cylinder, a little harder to replace.

    3. Maybe you just have a loose connection? small leak?

    I would recommend getting out a bentley manual for your vehicle -- or searching the internet like a demon for 525i clutch bleeding/troubleshooting articles.

    The slave cylinder is my bet!
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    When you bled the slave cylinder, did you remove it and compress the rod into the cylinder? It isn't clear from your description if you did this or not so I'm just asking in case. This is required to correctly bleed them. There is a special tool required or you can use a Irwin type wood clamp of a size large enough to go around the cylinder and extended rod in a pinch.

    If you are using a pressure tank above the reservor, the compressing of the slave cylinder should be all you need to do. You may need to compress, bleed air out, compress again, bleed air out several times.

    Hope this helps.

    bobyang guest

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    To clarify the above, I bled the clutch and the brakes using the two person method of having partner press on the pedal.

    I wound up just letting the car sit overnight. The next day, I pumped the clutch a few times, went for a test drive and clutch function and pedal pressure returned to normal, I guess the self bleeding does work. When I bled the slave, I pumped about 250ml through the system with no bubbles coming out, so I assume the air was in the master. I also did not use the method of removing the slave and pushing the piston a few times. I was going to try that if the clutch was still giving me problems.

    Thanks for all the help.
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    Thought I would ask here vs. starting a new thread.

    Car is a 2003 E46 330i with manual transmission.

    As part of my two year brake flush today, I hooked up my Motive bleeder and did the four calipers, no problem.

    I had my 7 mm combo wrench on the clutch slave cylinder but it slipped off and an entire bottle of fluid came out before I could get the wrench back on the nipple and close the valve.

    I heard the depressing sound of air sucking through the master. :(

    I re-filled the master and re-bled the clutch.

    My question is, what is the proper procedure to bleed the clutch?

    I've read where you should have an assisstant push the clutch down a couple time, hold it down, then release the pressure on the slave briefly to expel air.

    My Bentley manual describes a much more complicated procedure involving removal of the slave cylinder and a special tool. I can't quite work out how this works.

    I drove the car after I did the job and it seems fine, no problems, with a reasonably firm pedal.


    bobyang guest

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    I bled my clutch using the assistant pumping method. seemed to be fine. I wouldn't worry too much. I'm told the clutch is self bleeding anyway.
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    If it seems fine, then it is fine. You will know if there's air in there. Some of us (me included) are just lucky.

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