Master Cylinder: Disassembly
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 BMW M5, 2003 BMW 540i, 2003 BMW 530i, 2003 BMW 525i, and 2002 BMW M5. However, it is still accessible from the selected car via links, so may be relevant.
Push in primary piston and remove plug. See Fig 1. Remove retaining ring from end of cylinder. Remove primary and secondary piston assemblies and stopper washer. Disassemble piston assemblies, noting number and position of parts used for reassembly reference. See Fig 1.
Courtesy of BMW OF NORTH AMERICA.