Wet noodle clutch pedal

Ok, I've spent the last day or two searching and reading before making this post. Interested in your opinions on what the problem could be/solutions.

 

Long story short, went from a t/s modded vf38 setup to a vf39 ewg setup. Obviously the vf39 is a STi fitment turbo which now routes my FMIC piping very close to the clutch slave cylinder. About two days after doing the install I was driving home during lunch and went to clutch in to shift. The first 1/4 of pedal travel felt normal (i.e. stifffff), then the pedal just went to the floor. (ACT HD clutch with HD PP w/~15k miles on it)

 

Here's the thing, the pedal still works, just very very low resistance. I can still shift, the engagement point is now very high on the pedal. Doesn't stick down. No funky noises or anything when shifting. I don't believe it's clutch mechanical b/c there are no noises, car still holds in gear. Could the pressure plate have gone bad but not make any noises of destruction?

 

I flushed and bled the clutch hydraulics last night, a few air bubbles came out, but no change in the clutch pedal (still a wet noodle). I ordered a slave rebuild kit and also a stainless clutch line. I didn't see any leaking out of either slave or master either.

 

My gut is telling me slave cylinder or clutch line just due to the additional heat source next to them, and I am pretty sure the slave and clutch line are original on the car. The master may have been replaced b/c mine has a bleeder screw on it--I didn't think they had bleeder screws stock on the master.

 

Any other thoughts on what it could be? Am I going down the right path? Part of me wants to order a new master just to be on the safe side, but the other part of me looks at what I've changed on the car and the most affected area is the slave/clutch line. Unless it's just totally unrelated and coincidence...you are welcome to call me a crazy person as well!

Stock does have a bleeder screw on the CMC. Easier to bleed the MC that way. Don't have to pull to bench bleed.

 

Mine was doing this after I replaced the stock clutch line with an AM WRX SS one which turned out to leak. After I replaced the clutch line and re-bled everything the issue went away. I have the same clutch setup as you do.

 

When you have someone press down on the clutch pedal, does the slave cylinder move, then slowly return? If so, I'd start with rebuild/replacement on that end, re-bleed and verify. If the slave doesn't move and stays in the extended position, it's more than likely that your CMC is going. Time to replace.

 

Question - have your CMC reservoir every run dry for any reason? Did you bleed it afterwards?

The slave does move and does slowly return. It disengages the clutch just fine, but it's the return that feels super loose. Yeah, I thought I should start at that end and work my way back. Got the slave rebuild kit coming tomorrow with a goodridge stainless line. So will be trying that with a rebleed, fingers crossed it works. Just had to get the crazy thoughts out of my head.

 

No, the CMC res has never run dry. I flushed/bled the system completely yesterday, never let the fluid go dry in the res.

 

Figure I'll yank the slave, replace the inside bits with the repair kit parts. Replace the clutch line, then once the system is fully connected again, bleed throught the slave. Now should I "pre-load/fill" the slave before hooking it back up or is the slave being dry when I start the bleed not as bad as the master going dry when bleeding?

 

Thanks for the reply SBT

No need to pre-fill the slave, just lube the surfaces with brake fluid when you do your rebuild.

 

smitty is having similar issues with his. Going to replace the SC tomorrow, possibly the CMC as well. Hopefully, starting with the SC and working backwards will get both yours and his back to health.

 

GL and post in here your findings/fix.

My 00GT wagon would do the same thing if I sat in traffic for a long time.

 

The fluid was getting to hot. After it cooled it was fine.

 

I belive you can buy or make a heat shield for where ever you need it.

Update, rebuilt the slave cylinder, the ss line was too short so had to re-use the stock.

 

Pretty sure it's mechanical now, specifically I think I have a cracked pressure plate. Pedal feel is firm with car off, gets wonky with car on. 1st pulls hard, 2nd will pull but slip near top rpm, 3rd and up hold as long as I don't get on it. It's a weird slip too, feels like the pressure plate just isn't holding when it slips, doesn't feel like worn out clutch slip if that makes any sense.

 

Noticed a weird grabby feel when you hold the clutch just at the engagement point.

 

Have about 22k on this act hd setup with streetlight flywheel. Never had one go this early, never tracked but I do drive aggressively.

 

Looks like I know what I will be doing this upcoming weekend. Think I'm going to try out the comp clutches this time around.

 

Will update once I yank the transmissio.

Sucks to hear that. Good luck with the removal.

Yeah, it'll be the third time I've dropped the trans out of the car. Last time it was to replace the input shaft seal and then every seal I could get at with the case cracked open (figured why not). Did it myself last time, probably will end up doing it solo this time as well Oh well, at least I can leave the trans under the car this time...ha

SBT, i replaced the SC yesterday and while its not as bad as it was it still doesnt feel right. Also, the crickets under the hood are driving me crazy!

T-Minus 23:53:00 until the clutch job begins.

 

Hope you get yours figured out smitty. Mine def is mechanical.

The crickets means that something is out of alignment after the install...most likely the clutch fork. We can fix that. LMK what time you're coming by today so we can look at the rest of the system.

Get off at 330, so I'll run home and let the dog out and then come by.

http://img.tapatalk.com/d/12/09/15/9u4u4aty.jpg

 

The culprit.

Time to give ACT call about a warranty replacement

Yeah, I will be doing that Monday. From what i've been reading, seems an odd amount of this series pressure plate from a little while back seem to crack. A lot on the dsm forums about the diaphragms cracking.

 

Got the comp clutch 2600 ceramic segmented clutch delivered today. She'll be going in tomorrow morning. I was going to put a tsk3 kit on for good measure but I'm torn b'c the tob that came with the comp is very nice.

 

Hopefully act will give me a new pp and maybe reface the clutch disk. I'll take my streetlight flywheel and get it resurfaced and maybe it'll find a good home lol

 

Yanked my leaky cv while I was at it today and took a 'break' to wrap my downpipe. My car owns me ha

You may be ok with a little high temp grease on the snout for the TOB to ride on...

Yeah, went with the TSK3 kit. My snout was not in bad shape, but I could def tell there was some minor wear on it. Better safe than sorry, I don't want to have to do this again for at least another two years *knock on wood*

 

Started the warranty process with ACT this morning, will be taking pictures of all the parts tonight to send to them.

Yeah, went with the TSK3 kit. My snout was not in bad shape, but I could def tell there was some minor wear on it. Better safe than sorry, I don't want to have to do this again for at least another two years *knock on wood*

 

Started the warranty process with ACT this morning, will be taking pictures of all the parts tonight to send to them.

 

Thank you for telling me that. That's the way I would have gone, TSK3.

Props to ACT for warranting their product way outside of 90 days. Just got the call, they are going to give me a new pressure plate, and offered to resurface the clutch disc (said it was at the end of its life--odd after only 18.5k miles) and resurface the flywheel for $75.

 

Just wanted to update and call it case closed for this thread lol