Brake Issue. I know the problem but not the resolution

'92 Grand Voyager

Front right brake grinding sound. It appears the top of the caliper housing (cast iron thing the brake pads hold on to) is rubbing against the edge of the rotor (falling on it) and making a small channel into the cast iron housing. Now I have replaced the rotor and housing twice, thinking I was given the wrong part, and the noise goes away for a few months then comes back. What am I doing wrong? What do I need to do to lift the break house off the rotors edge? I have never had this problem with the left side even though I have replaced the same parts.

Thanks

Make sure that the sleeves, bushings and caliper pins are all in condition.