Rear disc brake mechanism details for the 323i model:
1 - brake disc; 2 - protective cover; 3 — support; 4 - brake pads; 5 - locking pins and cross spring; 6 - guide spring; 7 - locking spring; 8 - protective cap; 9 — nipple for bleeding the brake drive; 10 — brake lining wear sensor; 11 — parking brake system drive cable; 12 — cable bracket; 13 — parking brake shoe; 14 - parking brake adjusting ratchet; 15 - locking spring; 16 — parking brake shoe tension spring; 17 - retaining spring and pin of the shoes; 18 — release mechanism.
(The original article is located on BMWman)