sounds like you have oil on your pads ways you can try 1.sand down the pads a bit, so it will have fresh material (it might not responded, when you put it back in, thats ok just keep using it till it does, just needs to wear back in) 2.try burning the surface (this is trying to remove th oil in the pads) 3.drown in white spirit, then set it a light (this is trying to remove th oil in the pads) 4.new pads hope this helps