Barty

Car is 97 A4Q. I have done a search and several suggested master or slave cylinder problem. My question is: Is there any way to tell which one is bad?" I would hate to replace both. I have been checking the brake fluid level and it does not seem to drop so the "see where the fluid is leaking from" method will not work. It seems like some component is failing internally but the question is which one. Thanks for your help.

BTW, this condition only occurs during warm weather and I can pull the pedal back with my foot. Then, everything seems fine. I am just affraid this problem will get worse in the least-convenient moment.

BSCA4

Clutch Slave cylinder. It will eventually fail that render you clutchless. Replace it now.