G,Day daturley .
I now understand what you mean ,You are reducing the "Thickness "of the expander !!
To deglaze the axle housing where the brake discs contact I use a 5 inch angle grinder with one of those Flapper discs it is made up with layers/strips of emery cloth the best things I ever bought ,with a bit of practice you can do anything with them ,grinding ,they will remove three times as much as an ordinary grinding disc down to even Polishing ,as i said with a bit of practice,try one.
Did you change the shaft seals and housing gasket?