brake drums do not have a lip to hold oil for filtering...
its just a drum with an open top it would just throw fluid every where with out filtering...
i am even considering making a torque converter centrifuge since it has a closed top i just have to spin it while mounted true to a motor or shaft and cut a hole in one side to make a bowl and chisel out the turbine wheels ...
i do not have a lathe and its 100 @ hr for machine shop work here and they charge 30min just to chuck something up in a lathe not to mention re-positioning something..
i have already made a tuna can centrifuge , i tested it with the weight of heavy gear oil ... but i dont have a way to heat the wmo to 200* at the moment to filter it yet...
i have been thinking of cutting it 50/50 with pump diesel and running it through .. but i eye balled the holes and its off a bit ..