Sucky brakes

I have a 74 duster 318 auto with pw steering and brakes. The issue at hand is my brakes are sketchy at best lol. I can apply the brakes and it will travel down about 2in before making a difference and when it finally does catch it goes from very little braking to almost immediately stopping within the next inch and a half. I'm trying to explain it the best possible way I can. Has anyone else ran into this issue before any suggestion would be greatly appreciated. Thanks in advance.