No, the brake pedal should feel firm. It sounds like air somewhere. What is the status of the pads? If they are near the end of their useful life, you will get a long throw on the pedal, draw more brake fluid from the master and possibly, if the level isn't high enough, suck in some air. Take a look at the master cylinder resevoir and get an eyeball for leaks and pad wear.
1987 BMW 325
[This message has been edited by jeffsr (edited 03-25-2000).]