Clutch pedal engagement changed!?!?

[SuperFast3000GT]

HELP!! lol

I had a new xtd stage 3 clutch installed almost 2 weeks ago. Before, with my old slipping clutch, the clutch pedal felt weird and the clutch wouldn't engage until I let up pretty high off the floor... about half way, maybe more. It was like that (the high pedal release) long before the clutch was completely bad. (a year) I almost felt like whatever caused the bad pedal feel and high release is also what ruined the clutch in the long run...but what do i know.

Once the new clutch was installed, the pedal engagement was low to the floor like it should be and it felt great. I was also hearing a new air like noise, kind of like a "swoosh" or a "shhhhh" coming from under the dash near the pedal whenever I pushed it in. I don't remember hearing that noise before the fresh stage 3 install, (there is a chance I just wasn't paying attention before but I don't think so) but either way, the pedal didn't feel all that great before the new clutch. After the new clutch install, I noticed the (new, at least I think) noise whenever I pushed the pedal in...and it felt 100 times better.

Now, after a couple flawless weeks and 9lbs of boost in first gear tonight...something changed instantly. I boosted, pushed the pedal in to shift, changed gear... and then instantly noticed that something had changed when I was lifting up off the pedal to re-engage the clutch. The clutch doesn't engage now until I lift the pedal about half way up off the floor...just as it used to do with the old clutch.

I thought it was hydraulic at first, (maybe still could be?) but the padal does still bounce back all the way out. (all be it possibly not as fast) I am now not hearing that swoosh/shhhh air type of noise inside the car anymore until I turn the car off and pump the padal. Any clues as to what happened? Why would the pedal travel to disengage/engage the clutch change in a instant?? What was the air type of noise I was hearing and why is it gone now? Surely it's related right? The problem started and the noise went away at the same time.

[x2percentmilk]

Is the noise an air noise or a cricket type noise? I had very similar symptoms when my release bearing took a dump and slowly / catastrophically killed my pressure plate, but the noise you describe it different.

The pedal should be adjusted as per the manual with a specific amount of play up top, I dont know what it is for turbo's and wont make up a number so someone else will have to chyme in or try to find it online, but I would check that absolutely first. I've had clutch engagement points give me headaches and symptoms like crazy, so give that a shot. I've had the point change on a week to week basis on and off for a while now too. The point WILL change a few times after getting a new clutch as things are settling in.

If pedal travel feels normal its probably not hydrualic, but might as well check under the dash for fluid, the slave on top of the transmission, and a quick look at the lines.

Those are just easy things so we'll have to go from there.

[SuperFast3000GT]

To answer- I guess I did actually have a "cricket" type of noise, but that was before I had the new clutch installed. It was what I had called a "creak" or "creaking" noise coming from under the hood...but not inside the car. The faster I pushed the pedal in or out, the faster the creaking was. (and I only noticed the creaking while parked- and just to make sure I mention- I'd also hear the throw out bearing rattling while parked... now the new OEM TOB installed squeals) After the new clutch was put in, that creaking noise was and is completely gone.

I guess my first question should be, should I even be able hear a noise when pushing down on the clutch pedal? After the new clutch was installed and everything was (seemingly) working properly- whenever I pressed the pedal in, it sounded exactly like I was opening the back hatch. (only much faster and not as loud- and to specify... yes the noise was coming from under the dash in the clutch pedal region) That hatch noise started happening right after the fresh stage 3 clutch install when everything was working correctly. The noise stopped tonight at the same time that the petal engagement spot changed to half way up off the floor board.

I did looked at all the lines, metal...rubber...you name it. Everything is still connected and is tight. No visible leaks with either the slave or master. I do know that stuff can change with a new clutch and may need to be adjusted some from time to time... but for a change to happen within a instant after the first major boost?? Something isn't right. When the hatch "shhhhh" noise I talked about under the dash was present, it felt great. Now that it's gone... it feels like crap and the clutch doesnt catch till really high up on the pedal stroke. Just like that, from one shift to the next.... it's gotta be related I would think.

[J. Fast]

If it's under the dash and it's hissing there's a good chance you have a bad clutch booster. On the back side of the clutch booster push rod there's a negative pressure chamber, an air chamber and a diaphragm.

A possibility for the noise could also be a bad or missing vac assist check valve on the back side of the plenum that assists the clutch system. Here's a diagram for some assistance.

If you don't have any physical leaks I would bleed the system down again and replace the check valve and if the problem continues replace the clutch booster or delete it if you have the leg for it

[SuperFast3000GT]

The booster isn't the same thing as the "clutch vaccum tank" right? Because vaccum assist is already gone.

As of this morning, the "shhhh" noise is back after I first tried removing the rubber booster hose with the check valve and capped off the plenum. I took it for a test drive and the noise is back and it's feeling a little better than it was last night but still not 100%. The pedal pressure didnt really feel that much heavier, if at all, with the booster line disconnected. I then hooked the booster back up and went for another test drive. The "shhhh" coming from near the pedal inside the car wasnt nearly as loud as it was with the booster disconnected.

Also, I noticed today (especially with the booster connected) that if I pressed the pedal in, I'd hear the shhh noise....change gear....and hear the shhh noise again during the next shift. Over and over, so on and so on.... But, if I pressed the pedal in repeatedly (pumped it) without engaging the clutch, the noise would stop until I re-engaged the clutch again the next time...then the shhh comes back.