Slave cylinder failing immediately.. what am I doing wrong!?

[garyjpaterson]

So clutch went to the floor ages ago, finally got round to replacing the slave, pressure bled it from the reservoir (RHD so it has its own), press the clutch a few times and immediately the fluid is spilling out of the bell housing. After taking the new slave out, you can see its completely failed, and I assumed it was just a dud.

So tried again, new slave, this time I took some advice and reverse bled it from the bottom up with an oil can, seemed to bleed no problems with the fluid reaching the reservoir nicely, but again a few pumps of the pedal and its dripping out of the bell housing again.

Am i fitting it wrong? Is there something wrong with my clutch system (release bearing or lever?) that is causing the seals on the slave to fail immediately? I can only assume I'm doing something very wrong here, though I did the same thing when I first got the car years ago and it worked fine.

Cheers for any help

[jclausen]

Unless there is some thing wrong with the master clyinder for the clutch that is causing the new one to fail, it's not uncommon to replace both when one fails, considering age of both parts

[bimmer@15]

It ks unlikely but possible, if you you have a different clutch or the slave cylinder is made for an aftermarket clutch you could be hyper extending the slave and forcing oil out and possibly damaging the slace cylinder

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[T.Dot E30]

was the slave inserted correctly with the piston against the fork?

If you just stick it in there with nothing to push against, then yes first time you press the petal the piston will come straight out. When placing the slave into the bell housing, you have to ensure it is pressing against the clutch fork, it will take some pressure to compress the piston to get it mounted correctly. Whereas if you move the piston too far up or down so that it is not touching the clutch fork, then the piston will shoot right out the first time press the pedal.

[ross1]

Is it coming out in one piece or has it exploded? If the later then installation error.

[garyjpaterson]

Yep, you are right! I was putting it in without the rod meeting the lever properly, so it just pops straight out.

I seem to have gotten away with this one, the first exploded entirely (got the bits out via a magnet), but this one was in one piece - I'm not sure if the seals are damaged or not, but I installed it correctly (which wasn't easy, I knew it was too easy before lol), bled it and all seems to be working without leaks. Clutch seems lighter than I remembered, though I havent driven the car in over 6 months so not sure.

I'll keep an eye on leaking and the fluid level, seems good for now. At least now I know what I was doing wrong, very glad to have it moving again, its been too long.

Thanks guys

[demetk]

You can push the piston back into the slave body.

[762Armo]

I went through something similar a few years ago. Turned out I had ordered the wrong pivot pin, which was shorter than what I needed.
Sounds like you got your situation figured out though.