BMW Repair: hydrolic clutch, clutch master cylinder, clutch disk

Question
my mother in law has an 87' bmw 325i that when the clutch is pushed down it doesnt return. it is hydrolic so i am lost on how it works exactly.
it does have a slight leak on the boot near the pedal. so my question would be is it loosing prime or how does this system work.


Answer
Cory, any leak in a hydraulic system will introduce air in the system where the fluid would have been. Air will compress as where fluid will not. Your clutch master cylinder (behind the pedal) creates hydraulic pressure with your foot applied to the pedal the pressure is transfered through a hydraulic line to the Slave Cylinder. The Slave cylinder is mounted on the transmission housing and is reponsible for depressing the pressure plate spring and releasing the clutch disk allowing gear change with out gear clash. The slave cylinder does this via a rod that is extended into the throw out lever which actuates the pressure plate I mentioned eariler when hydraulic pressure is received from the Master cylinder. So if you have air in the system or are low on fluid for any reason (leak)which will get air in the system and the air is compressed instead of the fluid being forced to transmit pressure and movement to the piston in the slave cylinder you will experience similar symptoms as your mother. Please replace what ever component is leaking and bleed the system of air and retest the system. Hope this helps. If it does please fill out a follow up survey or give another update post.
P.S. You get point in my book for having a mom that drives stick.
-Evan