Shoorty911

I had a new master cylinder put on last december and i have noticed since then when i brake the nose of the car dives and the rear end of it flies up.....i dont think the back brakes are working as they should.....i have adjusted both the back brakes and cant even get them to lock up or anything even on gravel....i know i have rear abs but i never feel the pulsation of the abs coming on.....probably because the back wheels never start to lock up....is there anyway i can change the brake bias...and how do i do this......because it is putting way to much strain on the front brakes and now my rotors are warped REALLY bad.....thanks...

shoorty