I recently overheard an exchange taking place at a car show about whether or not you could make drum brakes into "power brakes."
"Aren't drum brakes always manual and disc brakes always power?" the one fellow asked.
"That's right, it's why they have disc brake conversion systems," a second fellow chimed in.
"Whoa - not so fast!" I said, as I stopped to jump into their discussion for a second.