Series 3 LI rear brake set up

Rear brake cam on series 3. Should it have a washer inside and outside the engine casing, with the o ring and circlip on the outside?
I dismantled this to service it and only one washer appeared. Then I read it should have 2 ?
Cheers,
Ian
I dismantled this to service it and only one washer appeared. Then I read it should have 2 ?
Cheers,
Ian