Clutch pedal
 

I've been noticing that randomly after driving my Z, I'll get in to drive and the clutch pedal has no pressure the top half of pushing it in. At the half to three quarter mark of pushing it in, I start to feel the normal pressure. This usually happens after I've driven through a lot of stop and go traffic. The car is driveable when this happens. The clutch just engages closer to the floor than normal. It returns to normal after about 2-3 minutes of driving. I'm not really driving hard. Sometimes when I drive it harder, this is not an issue. I've checked the fluid level and it's normal. Anybody have any input? Everything is stock. I have the Z1 csc elimination kit and road racing clutch bought, but not installed yet

Yeap, your CSC or CMC is on it's way out. You can bleed it with dot 4 fluid to see if you can get by a little longer if needed.

As per Spooler, you've probably got a Clutch Slave Cylinder (CSC) or Clutch Master Cylinder (CMC) or both going out. All too common problem with 370Zs. :( Search this site for "CSC" and "CMC" for more info. Check the CMC level and condition of the fluid.

You might want to get a copy of the Factory Service Manual (FSM) if you plan on doing your own repairs. Nissan has had some copies taken down but you may still be able to find one.

Almost 100% certain the seals in your CSC are failing. Personally I doubt the MC is prone to failing because I could only find two people who confirm their master cylinder failed, but that's just my view. If you have the option too return the Z1 kit for the Zspeed heavy duty CSC or their version of the elimination kit. Good luck!

I've replaced my CMC 4x times. About every 20K miles. CSC never failed - I installed the Z1 CSCEK at 51K miles after my 3rd CMC failed. The kit and RJM pedal appear to have helped - I've only replaced the CMC once in the last 50K miles.

On my last Z my clutch master cylinder failed at 45K miles and I know a hand full of people that had their clutch master cylinder fail also. Installing a heavy duty clutch master cylinder is the only possible fix. I installed the Z Speed Performance heavy duty CSC and RJM pedal and did not have any clutch related issues after that. Also the Competition clutch kit I installed really helped.