Brake question to stop my car I have to put it to the metal

Brake question to stop my car I have to put the brake pedal to the metal and its real mushy and I can't register my car in maryland unless I PASS the inspection. And the dude that did the inspection said I have to replace my whole master cylinder in order to correct this problem to pass the inspection. I'm new to car modification and really don't want to play with my brakes. So any idea what could the problem be or a solution that does not involve replacing my master cylinder it would really take away from my rotor and brake pad upgarde budget. :uhoh: :banghead:

it really sounds like you have to do it, what's hapening is the piston inside is leaking by, and the pressure to the caliper isin't enough.