problem with brake system ford mustang gt 2004
I have ford mustang gt 2004 and i have the problem with the brake system, especially when applying soft brake I lose the brake pressure for no reason, then, I need to take my foot from the pedal and pressure again on the brake pedal to make brake pressure return and work. so what could be the problem ? and is there anyone faced this problem. ( note: I have changed master cylinder, brake booster, brake rotors and calipers from one month only).