I have a 2010 G37S. I replaced the Clutch Master Cylinder with an oem nissan part 3 weeks ago after it failed. I replaced the brake fluid and bled the line. The clutch pedal has been working great. A couple days ago, the Clutch pedal has been soft in the morning and stiffens up after 12 shifts or so. I haven't had problems shifting. Any advice is appreciated.