I replaced the brake system in the front, and everytime I reverse I hit the brakes to stop, to shift to Drive and move foward, I hear a knock after the car goes I hit the brakes again to stop at the stop sign and the sound again. It only happens once. I wonder if that'* normal. The rotor slides back on reverse, and on drive as well but when I hit the brakes. I will drive all day and the sound happens once after hitting the brakes comming from backing up only, and from moving forward and backing up till I hit the brake to stop.

I hope I explained my symptom clear.

Wow, sounds like a much detailed inspection of brakes/suspension is in order. When you say that you replaced the brake system in front, how extensive a job was it? Just pads, rotors etc. I didn't quite understand the part about the rotor sliding back on reverse, and on drive.

Hmm

Did the pads seat properly and did you use any break in procedure after putting the new brakes on?

I put that sticky paste, and lube the lug nuts. and the pads sat correctly. I tanken it apart several times. And it seems fine.

The brake pads don't supossed to move?

It sounds like you have a loose caliper assembly or a loose wheel. Check the tightness of the bolts that attach the caliper assembly to the steering knuckle. The factory service manual advises not to lubricate lug nuts and bolts. Some use a small drop of oil on the threads for more accurate torque measurement, but I believe it is safer to do them dry with bolts and nuts that are clean and run freely. The nuts should be tightened in a star pattern to 100 ft-lbs. The wheel holds the rotor in place. If you have a bunch of lube between the wheel and the rotor and are improperly torqued, this may be where the slip and the clunk are coming from. I would take 'em apart, clean off all the lube from the studs, lug nuts, and from the contact points on the inside of the wheel and the brake rotor, where the two meet. While you have it apart, check the caliper bolts and tighten them if necessary.