Hello - I searched for an existing thread of this issue I'm having but didn't find one. So I have a 04' 6spd Max w/ 80k + miles (30k + was put on from me). Since buying the car 2 plus years ago, twice this has happened - while driving, the clutch becomes sluggish part of the way down. I'm still able to shift. This lasts for about 2 to 3 miles then normal pressure comes back. I drove for another 10,000 then it happens again, then comes back to normal. Spoke to several nissan dealerships and or course they say replace it. Any other advice is welcomed.

 

first then need to bleed the system.

also check for any worn seals/leaks in the clutch resovior or slave cylinder

 

Old thread I know, but I've experienced something similar, and may have found a potential cause other than leaks/cylinders.

There is a clutch release damper in-line between the master and slave cylinder. Effectively it's there to prevent the driver from dumping the clutch, to save wear/tear on the frame and mounts. If there's a problem with this damper, it may cause problems in clutch feel but there will not be any leaks, and the cylinders may be fine.

You could try bypassing this damper with a hose, or by bending the hard line to go straight to the slave cylinder.