[coxster]

Hi all,
I haven't been able to find a definitive answer to this: When you bleed the clutch at the slave cylinder, should the slave cylinder be bolted up to the transmission bell housing? I did mine with the slave cylinder out/unbolted using a Motive and had some unexpected results (ended up blowing the slave cylinder). Also, if it should be bled with the slave cylinder in, how do you get a wrench on the bleed screw? Even with the back of the transmission dropped there's not much room.
Any help is greatly appreciated!
Thanks.

[relative4]

As you've demonstrated, yes - it needs to be installed.

[coxster]

Ok thanks for confirming what I suspected. Any tips on getting to the bleed screw with the slave cylinder bolted up? Looks like very little room to work.
Thanks!

[ctuna]

Anybody considered a reverse bleed from the slave to the master.

[Efthreeoh]

Most hydraulic cylinders need to be restrained or the piston will drive out of the cylinder when hydraulic pressure is applied. You didn't blow the seal of the cylinder, you just popped the piston out of the cylinder.

You can bleed the slave cylinder off the transmission if you simply restrain it in a vice or C-clamp. You just need to keep the piston restrained from moving.

On the transmission, I've used a small Craftsman 6mm or 7mm box-end wrench. I forget the size of the bleed screw hex, but it's either 6 or 7 mm IIRC. It's still a tight fit and a PIA, but the small wrench gives enough room.

[coxster]

Efthreeoh - thanks for the useful information. I hadn't read where anyone else explained it as clearly and simply as this - it makes sense. What happened with the previous attempt was i used the Motive power bleeder with the slave cylinder unbolted then after getting all of the air out, I went to the clutch and pushed it, it went to the floor and had to be pulled up by hand. I repeated this two or three times until the clutch stopped going all the way to the floor, then I pressed it a bit too hard and heard a pop. Under the car, the boot and piston had shot about five feet away and there was brake fluid _everywhere_. So now I get that the cylinder didn't have anything to stop it from extending too far (by pressing against the release fork lever). I thought i might be able to just put the piston back in, but these things being plastic, the surrounding plastic (not sure what to call it) cracked and I'll have to replace the slave cylinder.

I believe this one is an 11mm, plastic bleed screw.

[John 070]

Admittedly I have skipped it both times I bled the brakes, even when I did the DSC/Hydro....I always heard it's a very small amount and I had read some threads where peeps had issues....did BMW even touch it when the car was under free maintanance?

[Efthreeoh]

Originally Posted by John 070

Admittedly I have skipped it both times I bled the brakes, even when I did the DSC/Hydro....I always heard it's a very small amount and I had read some threads where peeps had issues....did BMW even touch it when the car was under free maintanance?

I'll have to verify, but I think the first time I bled the clutch line was north of 280,000. When I did the CDV delete at around 130,000, I clamped the clutch hose with a line clamp.

Note to all, use a power bleeder to bleed the E90 clutch.

[TheMidnightNarwhal]

Originally Posted by John 070

Admittedly I have skipped it both times I bled the brakes, even when I did the DSC/Hydro....I always heard it's a very small amount and I had read some threads where peeps had issues....did BMW even touch it when the car was under free maintanance?

I also skipped it reading threads of how much a pain it is to reach it. I guess it's not that necessary to do?

[coxster]

So, I got the new slave cylinder in, connected it and bolted it up to the bell housing. However, there is no room to turn a wrench to loosen/tighten the bleed screw. So I pulled back out and pressure bled it with the Motive. The piston remained compressed during the pressure bleed. I re-installed it and tried the clutch...and it went straight to the floor and did not return. I hand pumped the clutch a few times until it stopped going all the way to the floor. The pressure felt just like the last time when the slave cylinder piston blew. I decided to remove and re-bleed it again. I pulled it out and could see grease on the end of the extended piston that I had applied to the pivot fork, so I know it was hitting that. I pressure bled it again (no air bubbles seen) and re-installed it. No change. Any ideas on what I might be doing wrong?

[coxster]

Installed a new master cylinder - not much fun there - and getting the same results. About to bolt up the driveshaft and exhaust and have it towed to a shop.

[PhaseP]

I have been using a ratcheting wrench for that, 7 or 8 mm if my memory is correct. Earlier year builds, which mine is, has metal slave cylinder. Later years have plastic, which may have different size.

[coxster]

Just to close the loop on this:
Towed to shop and they determined that the slave cylinder rod was installed diagonally and blew the seal. Running like a champ now. Thanks all.

[Efthreeoh]

But didn't you get a second, new, slave cylinder?