Brake fluid leaking

[Dinan330ic]

I'm not sure where to post since my car is a mix of everything.

Anyway, this is a tranny issue. I have UUC's 11lb ltw flywheel, M3 clutch kit, and M3 slave cylinder, which was installed last summer. I've probably only driven it 3k miles (MAX) since then.

Yesterday night my brake fluid light started to flicker. When I got home, I popped the hood and my brake/clutch fluid was low. I filled it up this morning and drove to work. A couple of hours after I was parked, I see a little puddle underneath the tranny (like directly under it).

My question is: Is sounds like the slave cylinder is bad, but what are the chances that it will go so soon?

Is it possible that my Getrag tranny is crapping out (80k miles) from too much power?

[norcalbmw]

you have an s50 or m50 turbo?

[parolof]

if the tranny is going bad it would not cause that leak, I bet $5 on the slave cylinder :cool , or the hydralic pipe

[Dinan330ic]

norcalbmw - S50 turbo

parolof - Yeah, i'm guessing it's the slave cylinder as well.

Does anyone know what causes it to leak? It's not like I drop the clutch or do anything harsh when I press/release the clutch. What a pain.

[bmrtech]

The inner boot on your slave has gone bad. Take out the slave cylinder and
see if the boot is ripped. Did you purchase a new slave or a used one?

[parolof]

It's just the seal inside the cylinder that's worn, there are repair kits to rebuild them

[Dinan330ic]

Is the inner boot the tip of the rod that pushes against the fork?

I purchased the slave cylinder new.

Thanks guys for all your help. At least I have a better idea of what's might be wrong. I'm gonna check it out after work.

[norcalbmw]

wow i didnt know u could use a getrag w/ an s50

[bmrtech]

Parts warranty! :)

[parolof]

Is the inner boot the tip of the rod that pushes against the fork?

I purchased the slave cylinder new.

Thanks guys for all your help. At least I have a better idea of what's might be wrong. I'm gonna check it out after work.


No, that is just a dust protection boot, there a seal on the piston inside the cylinder, that's probably shot

[themadhatter]

unfortunatly these suckers go bad too often and can be dangerous if left unchecked.

replace the slave and the line for good measure, you should be 100% after the repair.

[Dinan330ic]

Thanks guys. I couldn't determine where the leak was, but I think i'm gonna go ahead and replace the slave cylinder anyway.

Results later.

[Dinan330ic]

It doesn't make any sense. Brake fluid is still going down very very slowly.

I took off the slave cylinder just now and everything looks fine except that the slave is covered in brake fluid. There MUST be a leak somewhere in the unit. There shouldn't be a compatability issue using an M3 slave cylinder on a Getrag tranny, right?!?! UUC's site even recommended the s50 slave cylinder for the 325's.

I still have my 325 slave cylinder. What would happen if I put that back?

[parolof]

If it fits fine, the only problem I can think of is that if it's a difference in the cylinder diameter, if it's larger the clutch will be harder to operate (or is it the ther way around?? :D )

[jrward]

yeah, slaves can go anytime, I had mine crap out (brand new) after only about 2 months. Heck, if you still have your stock one, bolt it in and see if the leak continues, if not, you found the problem. IIf i can remember correctly, the bigger bore = more force = firmer which explains why mine is so darn stiff. I had an emergency situation where my exploded the morning of an autocross and the only one in stock was the larger 13/16 e30 slave, but it works great.