E34 rear rotor questions

[canada5]

This is my first time for servicing the rear brakes and was surprised to find the set-up for the parking brake when I removed the rotor.

What is the reason for the inner drum brake as a parking brake?
Is this common in other car makes?
Why are the rotors considered disposable instead of machining them?


Thanks.

 

[epj3]

Except for hydraulic parking brakes like those on some cars, and cars with rear drums... it's the only e-brake setup I've ever seen. It's a very simple and space saving design. I don't understand your question though... if it weren't there, where else would it be?

They aren't supposed to be machined because it's a BMW! Welcome to the world of BMW repairs