Need Brake Help...any Suggestions

Hey guys i was wondering if anyone has run thru this in any car and what it was, my friend is a mechanic and he's thinking its the brake booster, but id like to get some feedback.

Problem: The brake pedal is really hard to push down, i mean we just put front rotors and pads on and bed em in and the pedal is still hard feels like ur driving on drum brakes. I took the rears apart and the rotors are junk not worn evenly so i didnt put rear pads on (which i have) but gonna wait for rear rotors as well.

Found a seized front slider but still hard brake pedal does anyone have any idea?

Thanks guys

[Wildman]

I just changed mine today. New pads and new rotors. Mine only get hard and feeling like you are manually braking the car after my rotors are shot. Did you bleed the brakes?