Trouble bleeding the clutch in my 325e...

[Bimmerfreak87]

My 325e slowly lost clutch pressure over time until finally I couldn't shift gears anymore. I bought a new master and slave cylinder since one was most likely the culprit and they looked like factory parts that could stand to be replaced regardless. I read they should be replaced together anyways, so I was fine with replacing both.

I replaced the master and slave and tried to bleed the system, but I seemed to get endless air and no fluid. I finally heard a small whistle of air and took a closer look to find a small cut in the hose that connects to the top of the master. I got some new hose and hose clamps to make sure it would seal properly. I tried to bleed the system again and I'm not getting any fluid. How do you bleed the e30 clutch system and are there any tips or tricks I should know? I hope to fix the "e" this weekend so I don't put any more miles on the "is" commuting to work. ;)

Note: I read to bleed an e30 you pump the clutch pedal x50 and leave pushed to the floor, open bleeder screw, close bleeder screw, pull pedal back up, and repeat until pressure builds and no more air/bubbles. I did this and got no fluid...
Note: I did NOT "bench bleed" (bleed while off car to get fluid in seals) the master or slave as I had never heard of this until the other day and have no idea if it matters.

Thanks in advance for any help! :D

[Danny]

Gotta bench bleed.

I got around this by using a hand vaccum pump to suck fluid out of the slave cylinder's bleed screw, I would NOT recommend this way. Just bench bleed it.

[Bimmerfreak87]

So just take off the slave, bench bleed it, and install it again? I don't have to take the master off... right?

To bench bleed I would just... pour fluid where line connects and... move it back and forth?

[Danny]

http://www.youtube.com/watch?v=uj1dMdYgRK4

[Bimmerfreak87]

Thanks for the info.

[Bimmerfreak87]

I finished bench bleeding the slave and then tried to bleed the system again to no avail. When bleeding the system this time I got fluid with air bubbles to start and eventually solid fluid with no more air bubbles, but the clutch pedal still goes all the way to the floor and has no pressure. I kept bleeding for like 45 minutes with solid fluid being pulled. What do I do now???

Called a shop and the mechanic said to pump the pedal 3x very slowly to build the pressure and then release and tighten the bleeder screw very quickly. Said to repeat until pedal has pressure (said the 50x pedal pumping is too much :tsk: and lets in air if pumped too much??). I tried this method also for 30-45 minutes and pedal still goes to the floor. I need my "e" back! ;)

[jlevie]

Did you replace the clutch master and slave with new (not used or rebuilt) parts? Your difficulties sound like a bad clutch master cylinder. While rare, even new parts can be bad. But used or rebuilts are a roll of the dice that frequently comes up snake eyes.

The other possibility is a failure inside the bell housing. You can check for that by dismounting the slave and using a screwdriver to try to disengage the clutch. That should be very difficult to do. If it is easy, the transmission is going to have to come out to see what has failed.

[99em1]

Yeah it sounds (if you've bled correctly) that there is a problem outside the hydraulic system. I doubt its defective new parts. It is a very unlikely scenario especially with many other possible issues that are much more likely. I'd say see if you can see the clutch fork by peeking through the slave mounting hole and make sure the fork is flush against the surface. Could be a failed pivot pin (happened to me), or something else who knows.

But first things first make sure you bled 100% first before tearing shit apart. I've heard a few times that BMW's are "self bleeding" and I can tell you from my experience, and those of some indy techs I've spoken with, that this is not the case. Bleeding sucks, and takes time. My recommendation is to pressure bleed first, then bleed the slave. Both are fairly easy and quick and should get you going in the right direction. For the slave, I took a piece of scrap wood in the garage, drilled 2 holes relative to the 2 mounting points on the slave, inserted 2 threaded rods to the holes, lined up the slave and tightened the nuts to the rods.

Wow that sounds confusing, but really I was just simulating how the slave attaches to the bellhousing on a 2x4. No need for tools to bleed that shit. Except a socket wrench. Took 5 minutes to make and it was freeee.

If that doesn't work then you have some serious work in your near future.

Edit: after reading your other post, I wanted to note I had the same problem. Solid fluid just using the hand pump method. I can only say after the slave bench bleed with the wood rig, I could feel with my hand a HUGE difference in stiffness in the slave rod. After only a pressure bleed the rod was stiff enough to drive the car but not enough to be "right". After bleeding the slave separately, I had no issues with the clutch.

[Bimmerfreak87]

Thanks for all the help and responses everyone. I did replace the slave and master with new lifetime warranty parts so I also doubt they are the problem. I will try to bleed the slave again using some similar method to the confusing one mentioned ;) above, but I found a European specialty shop that said they would bleed it for $60. Shop won't have time to do it until Wednesday though so I will keep working on it myself until then. At least I can narrow down the problem next week or hopefully get my car back. :D

[m_dudey]

make sure the slave is installed correctly. if the push rod is not aligned with the release fork, you're not going to have any pressure. also a chance that you can blow the push rod out of the slave. I learned that the hard way...

[F34R]

It is like bleeding your calipers...how are you having issues? When i bleed I have a friend pump and hold the pedal to the floor then I tighten it back up. Repeat till it has no more air. And make sure you watch the fluid tank for the level. Don't want to empty it and have to start over, I fill every 10 pumps.

P.S. for people without a lift the car has to be level to bleed. If it is not then air could get in the line.

[bimmer630]

http://store.motiveproducts.com/european-bleeder--0100-p34.aspx

I think the BMW shop manual says to have the slave pushrod pressed in all the way while bleeding, they had a special tool to hold it in (you bleed with the slave off the trans).
also If you use a power bleeder the clutch master hose might pop off the brake master reservoir. I just put a hose clamp on mine

[Bimmer addict]

Remove the two bolts that hold the slave on the trans case. Make sure you have fluid in the reservoir... With the cap off the res, and the clutch pedal in the raised position push the slave cylinder push rod with your hand until you no longer see bubbles in the reservoir. You know you're good when the level of fluid starts rising up and down without bubbles. Bolt the slave back up and rock and roll. This method seems tedious but id rather fight getting the slave off then pumping the pedal and jumping up and down for 45 minutes pissing fluid everywhere.

[Madhatter]

Just loosen the two nuts holding the slave on the back of the belhousing. The slave cylinder should shoot back against the nuts. If you feel no resistance, like m_dudey said, you haven't got the push rod lined up in the notch on the back of the clutch fork and that will be your problem.

P.S. for people without a lift the car has to be level to bleed. If it is not then air could get in the line.

No it doesn't. The slave is MUCH lower than the fluid reservoir, you could just about roll the car over on it's side and as long as the reservoir is still full, it'll still run fluid through. The only way air can get in the lines (even the brake ones for that matter) is if you 1) bleed the reservoir dry, or 2) release the pedal with the bleed nipple open without fluid running out. You pretty much only have to worry about #1, but by the sounds of it, he seems to have bled the fluid through if it's coming through clear without bubbles.

Also, if you have a compressor, a $30 investment in a vacuum bleeder makes everything much, much easier.

[rjmcdermott81]

I thought I would share my experience since I just went through this. I have an s54/420g setup in my e30 that I'm in the last few days of being able to drive down the street.

With my setup the hydraulic cable isn't long enough to do the bleed by pushing the pin in with it connected. You can't mount it. So I had to mount the slave then connect the hose. Doing a bleed in the car took me a while to get right.

I was actually able to do this myself with the car on the ground. Just put a box-end wrench on the bleed valve and then pumped the pedal with my right hand. Here is the process that finally worked for me:
1. Push pedal down and hold it
2. Open bleed valve for 5 seconds then close it quickly
3. Release pedal
Repeat 5-10 times.

I initially was opening the valve, then pushing the pedal but that didn't work. I assume it was letting air in the line.

My first attempt was a complete fail when I used an e36 slave. I did the bleed by pumping the pin and it was super easy but as you can see in the pick below....it didn't work out well for me. I think when I mounted it I must have had the pin just on the edge of the clutch plate because after about 3 minutes of using the clutch I heard a pop and then as I pumped the pedal fluid came pouring out of the bell housing. Luckily I didn't have the pin drop in there like some others did....