Brompton Rear Brake Caliper Assembly Schematic
I cannot comment to the previous answer so I will write a new one. The order specified in the previous post is different compared to what the data sheet says.

The order of components for the brake caliper assembly are documented in the datasheet ds-brcal issue S1062. Unfortunately it is not seem to be publicly available on https://trade.brompton.com. However, an online search can reveal the documents on other sites [1] [2].


Rear brake caliper
M6 washer
Carrier platform bracker (rear rack)
Mudguard bracket
Concave washer
Hole in rear frame
Concave washer
M6 washer
Spring washer
Lower stop disc assembly (including nut)