Magic Disappearing Brake Fliud

[ted280sl]

Hello,
  The rear section of my brake fluid reservoir seems to be low on a regular basis. I assume I have a leak. I replaced the master brake cylinder last year. I checked the connections between the reservoir and the brake line. I traced the line all the way to the rear brakes checking all connections and hoses. I also checked the rear calipers which were replaced a few years ago. I found no hydraulic fluid leaking anywhere. I was hoping one of our magicians / experts would have an idea of where my brake fluid is going and how to stop it.
Thanks,
Ted 1969 280SL

[BHap]

If you can't see anything that is "wet" along the brake lines or at the rear calipers, I would pull the master cylinder off and check the power brake booster for dampness out of the rear of you "new" master cylinder.  Also make sure the reservoir is not dripping where it connects to the master cylinder.  It has to go somewhere!  Good luck.

[GGR]

Yup, I would also check inside the brake booster.

[ted280sl]

I changed the master cylinder. I did not see any brake fluid in the back of the master cylinder. I installed the new master cylinder and bled the system. The brakes are great and I have not needed to add additional fluid for several weeks. problem solved thank to our forum guru's. The disappearing brake fluid magic act is finished.
Thank you,
Ted
Ted 280sl 1969 290sl