@Maddog, Yep, that is what I changed with one correction, I replaced the rubber line that goes from the reservoir to the master cylinder. The SAC was actually in pretty far, but I really never noticed it until now. There is a procedure in Bentley that goes over the SAC reset. My clutch has actually been in almost 2 years.
@Axel, yes - none of the changes fixed the issue, although putting in the new slave did change the behaviour a bit. It wasn’t until pulling apart the tranny that things changed.
Yea, old clutch had the SAC almost all the way back. But that was stock clutch with 80k on it and a lot of abuse the last couple of months, as well as beta LA which I tried to be ignorant with. I wouldn’t expect stg3/4 clutches to have the SAC very far into it’s range, even with a good bit of launches. As I understand it, the SAC is there to adjust as the clutch material wears down to keep the engagement point roughly the same.
That’s why I was asking how far in was it as to possibly be a clue to the real culprit. As mentioned, the first time it significantly happened to me, I felt a difference in my engagement point afterwards (as much higher up, similar to my worn oem setup vs new being lower).
Horsepower also mentioned something about the SAC system, but never really followed up with it. IMO, if the SAC gets pushed all the way in, but I still have the same clamp force, it really doesn’t bother me having a high engagement and just makes speed shifts a bit easier (less travel on the clutch). But if there are drawbacks associated with the SAC system being all the way in while the clutch is still fresh, then that’s a different story. But I know very little about the SAC system and everything else beyond it’s general purpose.
So I finally got my ECU back today and therefore did some city driving (highway driving will be later tonight) to test out the new tune but this post is related to my clutch.
At one point, I gave it a nice burst of throttle in 1st and I felt my clutch pedal push back towards my foot as soon as I punched it and when I pressed it down again to switch into second, I had to push quite hard for it to go down. This is opposite of what usually happens. Really weird…
Then in 2nd the pedal got soft again and had a little difficulty coming back up (I didn’t punch it hard in second and didn’t go high in the revs. I’m assuming if I had, the pedal would have gotten stuck in the floor again).
Any thoughts? Why the push up in 1st instead of getting stuck down? I’m so confused by this issue. Would a bad throw out bearing still cause something like this?
I never had the pedal come up or any changes in pedal effort. My problem was always that the pedal would stay down after shifting. It is hard to say if that is the throw out bearing related just by the symptoms, but the TB shouldn’t come out farther than the fingers on the pressure plate can push it back. Also, pedal effort is usually a combination of the hydraulic system and the PP.
I just drove the car (first time in ~2-3 weeks) from my apt to the parents house. Was very easy on it, just cruising as it warmed up etc. Was on the interstate, downshifted gradually from 6-5-4-3 everything fine, punch it in 3rd and shift solid to second, pedal just stayed at friction point firm and engaged but no further up. Got out of it and back into 6th.
About 2 min later, it was back to normal feel, so downshifted again, this time I paused between 3-4 and not quite full throttle, and it grabbed and went into normal position/feel.
Then a bit later I tried a 1-2 full out. Pedal felt fine and it grabbed with no issues during the shift. Tried again, same result.
Very weird and I really don’t want to deal with pulling the trans/messing with the slave/etc especially with the headers on there now and how tight everything is. . . ehhhh.
Drove again tonight. Tried to recreate it the same situation. Never did anything weird or hung up, and it had plenty of time to hot etc. not saying the problem is gone, just weird how it’s so inconsistent.
I’m kinda feeling like mine is hydraulic related. At least I want to explore that fully before pulling the trans. Right now it’s becoming more common for high rpm shifts (only in 2-3,3-4,etc) the pedal stays right at the engagement point but isn’t slipping. For the most part, I can easily lift it up with my foot, and then it instantly feels and behaves normally until it sticks again. I feel like in general the pedal feels a slightly softer as well.
So that said, did you go with the USP metal slave and stainless line? I know the metal slave is a dated design, and there is debate that the newer plastic one is better due to heat etc, but wondering which ones you went with. I’d kinda like to just replace it all like you did, and wondering what you went with. Also the metal slave seems like it’d be easier to install with it being sturdier.
Also, did you do the master yourself. I haven’t seen any DIY’s on that and just wondering about that procedure.
Axel, I also got a more updated tune to hopefully address fuel trims and readiness codes. I agree, more civil for city driving and more lenient throttle response. Nice change up and bringing more of the gentleman’s civility back to the car rather than scolded red head step child full time lol.
