I replaced the Brembo clutch master cylinder today; the original one had developed a lot of free travel before actuating the slave. Being me, I had to take apart the old one. Seepage past the o-ring. What puzzles me though is why there is no spring to ensure the piston retracts fully. The piston does not capture a seal or cup-the only rubber part is the o-ring in a groove machined into the mc body. Never seen such.
