2000 Mountaineer
 

My Truck has a grinding noise when I break coming from the front end driver side, i've had the ball joints, control arm, tie rod ends all replaced. The breaks and rotors were replaced in March. I've been to two different mechanics, first one thought it was the ball joint, and replaced it. Any other ideas? I only hear the sound when I begin to apply the break to slow down, once the break is applied fully to stop it goes away.

You should check your brakes (calipers, pad shims, bent or mis-installed wear sensor, bolts, etc.) to be sure everything is okay and not your culprit. Could be a bearing. The only time you ever hear it is when the brake is applied lightly?

yeah when I'm like on the highway and I apply it to slow down, I hear nothing, and I have no problems when I have slam on the breaks, its like when I gradually break to come to a stop, I hear it.

in that case, it's probably just pad vibration. some brake pad shims and shim grease should sort that issue. If the brake pedal bucks at all while you're breaking, that means the rotors are warped and need to be turned or replaced.