Expert: Josh Fields - 11/18/2006

Question
I have an 85 535i manual transmission.  The clutch is not holding any pressure when I start out, but after the car warms up, and I pump the clutch hundreds of times, the pressure comes back.  I have both a master and slave ready to replace, but am curious if you think this may be a bledding or air in the system issue.

Answer
Tom,
 I have a feeling that you have a worn master/slave cylinder, and it's not an "air in the system" problem.  You can check your fluid, and see what color it is.  Sometimes when a seal is going out in the master/slave cylinders little peices of the seal will get into the fluid and turn it black or dark.  If your fluid is dark then that's probably the case.
 From my experience, when you get air in the system it will just feel spongy, like you are stepping on a dinner roll instead of a clutch pedal.  I had a brake master cylinder going out one time, and if you pumped it several times it would build up enough pressure to hold the brakes.  But if you were sitting at a stop light, the pedal would slowly bleed down, and you had to pump them up a little.  If you want to see if this is your problem.  sit in your driveway and leave the car in 1st gear while you have the clutch pressed in.  If the car slowly starts to move forward, then the fluid is bleeding by the master/slave cylinders and not keeping the clutch depressed.  You will sit with the clutch to the floor, and slowly the clutch will start engaging without you lifting off the pedal.  If this is the case... then your master/slave cyinders are bad