Hydraulic clutch problems!

[craig4ie]

Hey all

My 318is has been getting harder to shift over the past few days and the take point for the clutch has been getting lower and lower. I know this is most likely a hydraulic problem as I have been through this with my two previous cars. I searched the posts here and got quite a few matches with my problem but nodody seems to post how the problem was resolved!

so this is what I would like to know:

1. which part is most likely the culprit : master or slave

2: were there any obvious signs of leakage at the point of failure

On the previous hydraulic systems I worked on I dismantled the suspected part (slave/master) to check for pitting or gouges. I understand the e30 master and slave are sealed and cannot be dismantled and reassembled so I can't do this!

before anyone asks here are more details:
-the brake fluid level has not dropped from what I can tell
-no leaks visible from any of the lines
-I did a quick gravity bleed at the slave to drop the fluid level below the clutch point in the reservior and no air/shit came out, the fluid was clean

basically I wanna know if the master or slave can look perfecly fine (no leaks) from the outside but still be fucked up and leaking internally.


thanks!!!!

[craig4ie]

sorry mods, I shoulda put this in the Transmission & Driveline thread, please move it if you see fit

[erik325i]

basically I wanna know if the master or slave can look perfecly fine (no leaks) from the outside but still be fucked up and leaking internally.


thanks!!!!

Yes, it can. I had an e30 before that had a bad clutch master cylinder, although there was no external leak. It had different symptoms than you are experiencing though.

Instead of leaking the fluid out of the master cylinder, it would leak back past the seals back into the resevior. So, if you would hold the clutch pedal down (at a red light for example) the clutch would slowly start to engage because the master was leaking fluid back into the resevoir instead of holding pressure on the clutch. You would then have to use your foot to pop the clutch pedal back up because you already lost all the pressure.
It would work fine for normal shifting because there was not enough time for the fluid to leak back, but I just not allowed to hold the pedal down for any extended period of time.

-Erik

[jlevie]

In the absense of any leaks at the slave cylinder or in the lines I'd suspect the master cylinder. For the problem to be with the slave cylinder there'd have to be a leak.

[craig4ie]

thanks for the advice guys!