Pedal won't stay
 

Hey guys, so I have a 2008 350z and I have a JWT clutch with a lightweight fw. My pedal dropped to the floor so I changed both the master and slave cylinders. Both are factory. I know that having a factory slave will wear out because of the clutch but I press the clutch and it won't go completely down, just enough to not let me change gears or stall. If I pull the clutch back up and press it back down then I am able to change gears, but then the clutch doesn't come back up again. Could it still be because of the slave. Will buying a heavy duty slave from z speed help with this?

Welcome and sorry to hear about your problem. If you changed both the master and slave cylinders with OEM parts, you should still have a viable clutch pedal. More than likely, it's a problem with air being stuck in between the clutch master and slave; it could also be a hydraulic leak somewhere. Did you complete the work yourself? Is there any drop in the brake fluid level of the clutch master from day-to-day?

And yes, getting a HD slave from Z Speed is a good idea- it's not a question of 'if', it's a question of when the HR OEM slave goes...

No my mechanic did it. He said he made sure there was no air in the lines. The clutch fluid level has never really changed. Even after when my pedal dropped to the floor the first time.

It may be a blown seal in the clutch master or slave. Usually, you'll get a leak. Another possibility is your pro wrench may not have bench bled the master first and still isn't pushing any fluid through. Sorry to say, but your mechanic should have picked up on this during his test drive and before he gave to Z back to you.

Both are brand new though. And I was testing the fluid level right now and it is coming down every time I press the clutch.

wrong section, but will cut ya some slack.... i just came across this thread. it eliminates the csc, and puts in a fork again moving the slave to the outside of the trans. i would get this over the hd one, or the z1 option

https://my350z.com/forum/vq35hr/6123...ak-review.html

oh, btw.. when mine crapped out the dealership replaced it under warranty for me... with oem, less than a year later it went out again

Moved...

Ok so that worked the pedal doesn't go all the way to the floor. I changed the slave for the heavy duty one and that did the trick. Thing is, now it loses pressure or resistance. It doesn't crap out on me but at times the top half of the pedal has no resistance, yet the pedal comes back up all the way if I take my foot off it. What could be the cause of that?

Almost all the symptoms you're reporting indicate some air is still in the system. How are you bleeding the clutch? Even with the strange feel, does the clutch still operate?

Yea it still works. I can get in and out of gear but the engagement point is different every time the pressure changes

So, you still didn't answer the first question. How are you bleeding the clutch?

My mechanic does it all I do is pump the clutch. He unscrews it I guess then I keep it down to the floor and then he tightens it and I pump and repeats about 3 more times.

Gotta do it more than 3 times, imo. I usually bleed mine 10 times or so after the last air pocket comes through.

Also helps to bleed it right after getting the brakes HOT. Your symptoms sound like there are multiple air pockets between your master cylinder and the slave. That is why the pedal is so inconsistent.

Ok so I changed the master again. I can still shift and all that. There are no problems,but the pedal just won't keep complete pressure even though it comes back up. We bled the system so many times and still nothing. We're 100% sure there's no air left. ��

I'm not a mechanic, but from reading on here the system can be a total pain in the ass to bleed.