the copper grease was used and since yesterday, 3M cushion pads were fitted between the pads and the housing which has made a significant reduction in noise although not totally. The disks are only 2 months old. I am told that the noise comes from the pads vibrating on the disks when pressure is applied. By adding the cushion pads, this should eradicate the problem. However, as it is still there albeit not as loud as before, what else can I do?