1995 Ford Explorer front end shaking when applying brakes

When I apply my brakes, the whole front end will shake through out the braking. There is no vibrations or shaking when driving. I replaced both front rotors and pads thinking that I may have had a warped rotor, once replaced the shaking went away. A few months later it has come back and shakes during braking even worse now than before. Could this be caused by just buying cheap rotors or could this be a different problem like the hub assembly or something else. I did however notice the upper control arm is slightly loose on one side.