rear brake

[turtle254]

Looking in the reservoir of the rear brake, their is nothing on bottom but one small hole. I though there was a flap on the bottom hole to watch for as a check valve when cleaning? Am I missing something; Is their a diagram showing parts in tank? 
Thanks,Charlie

[sandy]

Rear brake has no such flap like the handlebar reservoirs.

[turtle254]

Rear brake has no such flap like the handlebar reservoirs.

Thanks