Here is why I think manufactures now don't turn brake rotors and brake drums because of liability. I know from having to do brake certification for on-highway motorcycles for a manufacture one of the requirements for NHTSA/FMVSS is that brake fluid reservoirs must maintain or have in them 15% more brake fluid if the brake disc or drum is at the minimum thickness or the drum to its maximum wear limit. Then with the brake pads or shoe material completely gone still the plus 15% remaining fluid in the reservoir. Think about when bleeding your brakes how you have to constantly top off the reservoir as you're doing it. All it takes is one mechanic to over turn a brake disc or drum, a set of well worn brake pads or shoes and someone forgot to top off the reservoir and a claim of brake failure, lawyers and expert witnesses measuring things and someone is going for the deepest pocket. So even the national service shops put the brakes (pun) on turning brake discs and brake drums to avoid any liabilities. You can still find or even buy brake turning machines but you won't find major shops or dealerships that will do them it's the way it has been. You can do it yourself as far as turning the discs but you'll probably find it cheaper and quicker to just buy some good non-China brake discs and drums the next time.