If you can make the brakes function normally by pulling up on the pedal with your toe, common sense dictates that you need a stronger pedal return spring. There should be NO contact between the pedal linkage and the master cylinder or the booster plunger before the pedal travels at least a healthy fraction of an inch- - - - -just like a clutch pedal.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!