Clutch problem

[97GSTspyder]

My friend has a 93 300z. This problem started happening about 2 nights ago.
He lost all clutch pedal pressure, and could only regain pressure when pumping it. We brought it over to my house, bled it, and didn't help much. We noticed it would hold pressure until we let it idle for a couple minutes with no one touching the clutch and then it would lose pressure.

So we tried bleeding the shit out of it again. After doing that, i got under the dash and adjusted it. I got it to where there was about 1/4in. of freeplay and the pedal had plenty of pressure. (It magically gained pressure). So we drove it around, and after letting it idle, the master cylinder kind of pumped itself up and there was no freeplay and the pedal was rock hard.

This same exact thing happens with the Eclipses, also. I looked to see what kind of master cylinder he has, and it's Nabco. The same brand that's in my car (97 Eclipse).

Anyway i re-adjusted the pedal out to about 3/4in. of freeplay. Started the car up, the pedal pumped up a bit, and the freeplay and pressure were perfect. Drove it around a bit, and suddenly the pedal lost all pressure once again, but came back after a few minutes. Now this is what it continually does. I gave up for the night. I'm thinking it might be his master cylinder, but being that's it's only 8months old (and so is the slave), i don't know. There are no leaks whatsoever in the system, and there is definitely no air in the system. I know it has to be a hydraulic problem. I believe there's a seal in the master cylinder that can cause problems like this. Even a minor nick in the seal would cause pressure loss. But he seems to think it's something else.

Anyone have any ideas?

[ExTrEmEDrIfT]

well first thing does it lose fluid ,do u have to keep adding fluid to it regularly or does the fluid level stay the same??

second does it have a seperate slave cylinder for the clutch fluid or does it get its fluid fed from the brake reservoir ???

[97GSTspyder]

it doesn't lose any fluid at all...

it doesn't get fed from the brake reservoir. he's supposedly getting a new clutch master cylinder later this coming week, hopefully it fixes the problem