86 TC Brake problem

I have noticed that my brake pedal has been getting softer like air is in the system. I checked my brake fluid and the front portion of the reservoir is empty while the back is full. A couple months back I replaced pads/shoes and did not notice any leaks and haven't noticed any around the wheels since. I'm going to flush/bleed the system but I'm wondering what could cause this to happen.

Thanks, Matt

hopefully you've fixed this by now! I just had the same thing happen. The front part of the master cylinder is for the back brakes. I had a brake line rust through just over the axle on the pass. side. easy to change, but I too thought the front end of the m/c was for the front brakes. But now it seems to make sense that drum brakes have a smaller reservoir.

What was your problem?