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Discussion Starter #1
I just replaced my CDV valve with Zeckhausen drilled out one. It only lost about 5-10 drops of the fluid while I was doing it. Now the clutch pedal drops to the floor and won’t return. I tried to bleed it and the air is coming out of the slave cylinder. The reservoir (which I understand is shared with the brake fluid) is all full. I don't understand where the air is coming from. Please advise.
 

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2006 530xi 6 MT
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I'm thinking that more than 5-10 drops were lost. The reservoir is not what it seems. There is an internal partition inside the reservoir that separates the part that services the clutch and the part that services the brakes. The partition goes most of the way to the top of the reservoir. It may look full, but it may not be over the top of the partition and therefore may not have a full side that services the clutch. The idea of this partition is so that if the clutch circuit fails, it doesn't take your brakes with it. This happened to me once when I flushed the brakes and clutch - my clutch pedal went to the floor. It was because the reservoir wasn't truly full. Found out the hard way :)
 

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In addition to what was said, If you can, you get your hands on a Motive Power Bleeder to get all the air bubbles out. You may have introduced air into the system. This happened to me when I did the CDV swap. Then keep bleeding it of air until your clutch pedal firms back up to what it was. You'll want to make sure to keep plenty of fluid in the power bleeder. Or you can do it the old fashioned way, have a buddy help you bleed the clutch.


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Discussion Starter #4
Thanks for the replies. I just fail to see the separator inside the reservoir. The fluid is all the way to the filler neck. Is it possible that the clutch part is empty when it is like that?
 

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If the reservoir is full up to the neck of the reservoir, then it has spilled over for sure. If it's still to the floor, you need to open up the slave cylinder and bleed it again.

Also want to mention I was using the Motive Bleeder when I did mine. It is very useful and makes bleeding brakes pretty fast and easy and less messy.

1100 should fit. As I recall I bought the "black label import kit". It came with an aluminum machined adapter. Fits my two BMW's and my daughter's 2007 Mazda 3.
 

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If the reservoir is full up to the neck of the reservoir, then it has spilled over for sure. If it's still to the floor, you need to open up the slave cylinder and bleed it again.

Also want to mention I was using the Motive Bleeder when I did mine. It is very useful and makes bleeding brakes pretty fast and easy and less messy.

1100 should fit. As I recall I bought the "black label import kit". It came with an aluminum machined adapter. Fits my two BMW's and my daughter's 2007 Mazda 3.
 

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I have a similar hand vacuum pump. I could never get it to work, I'm not even sure how it could work. You attach the line to the bleeder, & pump up a vacuum. Then you break the bleeder loose, & it's supposed to suck brake fluid through the bleeder. All mine ever did was suck air down past the threads of the bleeder & into the hose. I got very little brake fluid through the bleeder into the hose, just air.

I bought the motive unit a few years ago, it works great! I don't put brake fluid in the Motive tank, I just use it to pressurize the fluid in the master cylinder. I have to keep an eye on the fluid level in the master cylinder so I don't run it dry, but three or four fills of the master cylinder is enough to complete the process. And doing it this way there is no cleanup for the Motive unit.
 

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Discussion Starter #11
I ordered Motive Power Bleeder today but meanwhile tried bleeding using the old fashion push pull method and my girlfriend. The air just kept coming out after about 20-30 iterations. The reservoir is full. What gives?
I bled clutches and brakes on motorcycles and my old Nissan Maxima many times and it usually takes 5-6 iterations to fully fill the slave cylinder.
Is it possible that I damaged the master cylinder somehow?
 

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I have a similar hand vacuum pump. I could never get it to work, ... I got very little brake fluid through the bleeder into the hose, just air.

I bought the motive unit a few years ago, it works great! I don't put brake fluid in the Motive tank, I just use it to pressurize the fluid in the master cylinder.
This has been my exact experience too. The only thing that vacuum pump is good for is sucking old fluid out of the reservoirs.

I ordered Motive Power Bleeder today but meanwhile tried bleeding using the old fashion push pull method and my girlfriend.
If you're going to bleed the BMW clutch the old-fashioned way you need to remove the slave cylinder and manually move the rod in and out. PelicanParts describes it this way:

"Remove the slave cylinder from the transmission. Hold the rod firmly against the transmission. You will be holding the rod steady so you can allow it to extend as you bleed it. Have your helper step on the clutch pedal very slowly. Let the slave cylinder push you away from the transmission, but do not allow it to lose contact with the transmission housing. Open the 7mm bleeder, compress the rod, close the bleeder and repeat this step until the air is out of the system. Then reinstall the slave cylinder. Repeat the bleeding process, this time with the slave cylinder installed."

If you have an xDrive you may need to remove the prop shaft to pull the slave cylinder. That's why we spend the $$$ on the motive pressure-bleeder.
 
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