Cant get any breaks after changing bre...

You need to bleed them...bleed master cyl first,(if it has bleed screws use them if not use line fittings) then rr, lr, rf, then lf. Maker sure that all fittings are not leaking and that while bleeding, master does not run dry. Use light pressure on master, don't "mash" it down. You may need to bleed twice to get all air out.
good luck. (any problems, post back!)