Does anyone here know anything about the rear master cylinders fitted to 1970's RD's/TZ's? I'm rebuilding one and I can't work out how the top seal fits onto the piston, also where does the small brass plate go, under the seal or on to of it, between it and the spring? I would normally look at the disassembled one but everything was gummed up and it all just went everywhere and got mixed up when I pulled the old piston out.
