Just purchased an '03 Z touring edition w/ 44,000 miles.
Owner just replaced the clutch w/ Stage 1 kit & flywheel.
I was told it was Exedy all around, but turns out it's an ebay stage 1
clutch and F1 solid surface flywheel.

When the car is driven for the first 30-50 miles, everything is perfectly fine, hense purchasing the vehicle. Come to find out, if you drive long enough, the clutch pedal goes soft, and it's very hard to put in gear. If you let it sit for a few hours and get back in, it drives good again. Nice stiff pedal with good feel.

The clutch has maybe 250 miles on it, 150 from me.

I called the shop he had it install at and he wasn't of much help. I asked if he had bled the lines from both bleeders. He replied that he didn't bleed any lines, because he moved the slave cylinder out of the way with the lines still intact.

Does this sounds like it could just be air in the line?
Slave or Master cylinder failure?
Or worst case, am I already out $1500 replacing clutch & flywheel?

Thanks in advance for your help

 

Welcome. Clutch problems such as slipping are fairly easy to diagnose. Other potential problems are not. The clutch must be removed and inspected.

 

It sounds to me like the line may be getting hot from the exhaust since it is fine when its cold.. If the clutch was broken it would be broken all the time. I know the new braided steel lines have a heat blanket on them for just this issue.

 

Thanks for the advice.

I'll be purchasing some stainless lines and flushing the old OEM fluid out and replacing with someone with sometime with a higher boil temp. Then bleed the lines real well and hopefully that will help.

Any suggestions on stainless lines & fluid to use?

I'll repost when I finish to update when finished.

 

Use Motul RBF600, its a bit pricey but has a higher boiling point and hence no spongey feel. I had the same prob.
Hope this helps.

 

i ahd same problem, clutch line & synth fluid fixed most of the problem. But still get soft clutch once in a while. Trying to figure it out now

 

Okay, so time for an update.

I removed the clutch line where it runs to the slave cylinder but I could NOT get the other side off. I removed the clip that secures the line but the nut on the top side is stripped badly. I tried using some vice-grips but there isn't enough room to get them locked AND turn the bottom side at the same time. I did go ahead and put in some ATE SuperBlue and bleed the system clean.

I had a VERY hard time bleeding the system. It practically NEVER gained pressure. Someone pumped the clutch 5 times and held while I opened the bleeder on the slave cylinder. We repeated this over 30 times and still got very little pressure. I finally let it sit for awhile then pumped the clutch pedal strongly about 15 times and it built up some pressure, about the same as before, but obviously still not as much as it should.

I'll be taking it somewhere soon to replace the line with the stainless one I've got from Technafit (or something similar) but I'm now starting to lean towards the slave or master cylinder.

An interesting side note:
I drove the car home after this ordeal and changing into some white tennis shoes. The next morning I looked at my shoes and I had 2 very small blue dots from the ATE Superblue fluid on the top of my left (clutch) foot.
Makes me think master cylinder, huh?

Thanks

 

I've owned my 2006 Z for 8 months now! Owned 2 miatas previously and wondering why I hadn't owned a Z before now!! I've experienced the same clutch pedal fade recently and it's only occurring while driving around town in warmer temperatures. After my cars cools down the clutch returns to normal until I drive it again with all the start and stops and the fade returns with very little pedal available to engage the clutch. I was in the auto parts business almost 20 year and one thing I know is that when most parts are broken they're broken i.e. clutch master cylinder. I've read several post that sound like my issue and some of those problems stem from the clutch fluid boiling. Once that happens, your clutch will begin to malfunction. I'll be replace O.E. clutch fluid line with the braided stainless steel aftermarket and replace the clutch fluid with a synthetic brand which has a much higher boiling point. I'll let you know about the outcome.

 

My MC busted and that was the first sign, fluid leaking into the cab.

 

our clutch is shitty. sometimes mine gets stuck half way and it doenst want to come up. esp on hot days, or when i ride the clutch for a bit. you gotta be easy with the clutch, dont ride it too much esp on hot days, lol

 

oh yea, and its also pain in the *** to bleed our clutch. thats why i havnt messed with it yet. ill mess with it when the clutch fails, lol

 

I had similar problems and had the dealership bleed my clutch. Fixed my problems

Brakes need pressure bleeding... it sounds like the clutch does too