BigDaddyZ28

Yeah, I agree with you. If it was a restriction in the line, then our cars would do it on the way home from the car lot and GM would have a TSB on it...

I see a lot of guys posting about this problem after adding headers, which can make more HEAT... Heat is not our friend here. Just my 2cents worth.

Billnz28

iTrader: (4)

Mine stuck to the floor @ 23000. Ordered a clutch pulled the tranny the clutch fingers on the pressure plate were so wornout they looked bent and disfigured, clutch disk was in pretty good condition, The pressure plate was so worn out it couldnt push the pedal back up, I have a 02 that had a z-06 clutch. I ordered a spec stage III didnt do a drill mod just bleed the clutch and hasnt ever been stuck on the floor again and I beat the **** out of it.

Oscar Will

When everything is new and perfect it's ok......as the components get more wear, as the diaphram gets flexed a few thousand times it would have a tendency to get weaker and with less pressure this could happen. As for the restricted hydraulics and heat........it could be a factor but a restriction may not happen "all of a sudden" either. I have problems believing that enough heat could transfer into the hydraulics to effect this a whole lot.....even after back-to-back-to-back runs. Who knows for sure.

Racehead

I just installed an ASA cam in my car about a week ago. Prior to this install my clutch had worked perfectly every single time whether open tracking, open road racing, or drag racing. After I installed the cam and set my rev limiter to 6700 rpm's I noticed that when I started in 1st or 2nd and just went thru the gears that on every shift I'd have a little more freeplay than the shift before it until after 2-3 shifts the clutch pedal would be almost resting on the floor making shifting impossible. Well very rapidly this has progressed to where I am now. Which is even if I start out with a cold clutch and hydraulics, if I rev it to 6500+ rpms when I go to shift my clutch is on the floor and I can't shift. Even a simple 3rd gear roll on causes this to happen. If I go to shift at 6200 I have about an inch of freeplay making the shift kind of rough, if I shift at 6300 I have about 2 inches of freeplay making the shift even rougher and grinds sometimes. If I shift at 6400 then it almost won't shift at all and I have even more freeplay. If I shift at 6500 ..... well actually I can't shift at 6500 'cuz my clutch is on the floor I think that what's happening is that the clutch fingers are pushing the slave cylinder back into it's bore so you have to pump the pedal a few times to get it back out to where it can disengage the clutch. That's my opinion anyway.

If it was the restriction in the line that was causing the problem then it would have no affect in a roll on scenario. If it were heat that was causing it then it wouldn't happen when the clutch/car is basically still cold. It has to be the clutch ???

Judd

iTrader: (1)

Pretty much sounds like my scenerio, I added a cam, headers and I also bumped up the rpm limit at the same time. Hmmm, more rpm, more power, more heat,,,,, all kinds of possible reasons. And, yet no one yet can put their finger on it and say "yada, yada, causes the clutch to stick". Irritating for sure!

Rescue Ranger

iTrader: (10)

hmmm. I'm having this problem too, (resurrecting a sort-of-old-thread). Gotta love the search..

I called GM they said the 1st thing to check is for contaminated fluid, so I guess that'll be my 1st thing to do this weekend. Only lid/TB/catback here, no other mods, 43k miles.

Judd

iTrader: (1)

My problem went away,,,, after a new clutch, flywheel, slave and a master cylinder. Still don't know what really caused it. Just happy it's gone.

demonspeed

iTrader: (7)

I'm still sticking with this answer that I posted last year You'll see all these burned up thingys floating around in the fluid. IMO, that's what is causing the clutch to stick as, like I had said, they are impeading the flow of the fluid during each depression and release of the fluid. Just my opinion though...

Dal1as

I have this problem and have done everything. Nothing has worked. I mean I have done everything. Insulated, bled, replaced master, etc. It has to be the clutch itself.

joshp14

iTrader: (5)

Mine didnt start doing it until after my cam install. Now it does as decribed by many above...1-2 shift is good, but the 2-3 starts to get mushy, and the 3-4 gets impossible. I have an 01 w/o the drill mod. I have the insulated line from the tranny to the pedal. I'm betting its the clutch itself...

991LE

iTrader: (2)

Just to add my .02 to this thread. You have to realize that from a full power start, your clutch is going to slip and generate a lot of heat. A lot of that heat will be transmitted to the clutch hydraulic fluid. Older clutches tend to slip more and generate even more heat. Adding more power to your car will cause your clutch to slip more. I have been through the clutch sticking to the floor a couple of times, and once it was old overheated fluid and once it was a worn out PP.

I know some people drilled holes in their bellhousing to help with cooling. That along with insulating the hydraulic line seemed to help. In any case, I think it is caused by heat.

Judd

iTrader: (1)

Sometimes it may well be heat related, dunno. I do know that my car would do it when nice and cool so that kinda shoots down the heat related issue at least in my case. Unless you believe that the hydraulics can get hot enough to boil the fluid in what amounts to a few seconds of acceleration. How come the fluid didn't boil back when it was relatively stock making hot laps and getting the clutch so hot that it slipped all the way down the track creating a cloud of dust that people could actually see in the stands? I just don’t see it being my particular reason.

Fluid contamination is a legitimate culprit also but it doesn't explain why alot of us have the problem immediately after adding alot of power. No problem for 40K miles, then immediately after adding a bunch of power, it starts sticking to the floor. Did the fluid suddenly become contaminated in a couple of miles at pretty much exactly the same time I threw a cam, headers, cutout and a ported TB?? It could happen like that, stranger coincidences have happened. And I never did flush the system before replacing the master and slave. I kinda wish I would have once I found out how easy it was to bleed. That would have answered that theory.

I really like everyone's theories here. It's just that the only thing alot of folks have in common is the issue of added power. I have no doubt that the pedal sticking to the floor can and does happen due the heat or contamination, just don't think it would be the reason in my case at least.

I did see a explanation in this thread where the poster said it was due to wear on the pressure plate and disc and it results in the diaphragm over extending {or something to that effect}. Also in one of the above posts, a guy menteined that higher rev limits might have something to do with it.Both are good ideas, those might have a legitimate bearing on my car.

I did replace the clutch and beleive it of not, after around 45K miles, around 200 odd 1/4 mile passes and near the same amount of AutoX passes,,, it looked like it had plenty of life left in it but I didn't see it when it was new so it's sorta hard to compare. BUT it would manifest itself when cool or hot conditions. Going back to the RPM thing, I did raise my rev limit and was shifting quite a bit higher. At least two of us had the same thing happen, at the same time. We both added power and additional rpm and THEN started having problems. He might be onto something there folks, it would do it when hot or cold, contaminated or not or even if the fluid was contaminated or not. So far I like that explanation the best.

1999Daytona500PaceCar

iTrader: (2)

Makes you say - Hmmmmmm...

HavATampa

iTrader: (49)

Crap!! 33 posts, 1044 views and 9 1/2 months and this thread leaves more questions than answers. It's all good info but I am sick of the crappy clutch setups in these cars. A lot of good it does to have a potent combination if you can't get the power to the ground. I just added heads and insulated the clutch line while I was under the car. A few spirited red light launches and I had the dreaded pedal mushiness and then lot's of play in the pedal. And then the clutch started slipping big time. I'm wondering if replacing the reservoir with something bigger and using the Mcleod expensive *** replacement lines or doing a hard line replacement that is bigger internally like 383lq4ss did in another thread is the answer? Along with $1000 worth of Aussie clutch know-how. Geez...there's gotta be an easier cheaper solution out there?!!

Judd

iTrader: (1)

After a Spec Stage 3 clutch, flywheel, new adjustable master cylinder and 2001 up slave and lines,,, my problem is fixed. Wasn't too hard fix really but I still don't know exactly why the pedal was sticking to the floor. Although this point, I don't care anymore.

HavATampa

iTrader: (49)

What adjustable master did you go with Judd?

Judd

iTrader: (1)

I can't remember exactly who I got it from but it is a stock master that has been modified by cutting the end off and welding a new threaded piece on that a rod end threads into.

I do want to warn you that the master cylinder's rod end {the piece that goes on the clutch pedal} was too thick. The actual sperical bearing was too thick, I had to grind about 1 or 2mms from it in order to get the retaining clip into the groove on the pedal.

Like I said, I can't remember who I bought it from, just giving some warning that you might have to spend an extra 30 minutes or so grinding and fitting.

Transam64

Can this be explained.........My clutch only had this same exact problem on cooler mornings....daily driven in the summer. Centrifugal effects on the PP ( dismissed due to low rpm.) Heat, ( dismissed , car was still WAY off operating temp.) Bad slave design on the 99 & 00 yr f-bods.( corvettes have the same problem from 98 to 99. ) ( Plaussible) .
It's a bad design of the slave. I'd have to say that the drag racing theories are a result of just that.....but the amount of complaints about clutch pedals sticking to the floor for no apparent reason are enormous. GM tried to fix this with a recall...saying the spring on the pedal was to weak. BS....How does a weak spring on the pedal cause my clutch to engage itself on it's own free will and stay there???
To many details and not enough raw thought and intelligence are running this problem off the charts. Look at the basics guys/gals. It's a really simple system once you understand it. ( The fluid gets all "chunky" and black because of seal failure in the slave. that's what gm DOES'NT want you to know! )

HavATampa

iTrader: (49)

If it was "just" a bad slave design why do so many '01 and '02 cars have this problem? I see people posting about upgrading all the hydraulics to the newest and still have this problem. Nah, it's more to it than just the slave. Read some of the Corvette boards, even some of the new ones are having pedal sticking to the floor problems.

Thanks Judd for the info about the adjustable master. I have thought about doing this and have seen several write-ups, but until I can find a real reason to do this, I am holding off. I don't need something else to throw into the equation if it's just going to complicate things even more.

JRracing

iTrader: (35)

My car started to do this and I put all new parts in it. Spec3/fly wheel,master and slave. It worked fine for almost a year then I put a textralia in it and it is mushy and sticking to the floor sometimes. The fluid was dirty also. So I flushed it all out and put valvoline synpro dot 4 in it and drilled it. It is still mushy. I'm going to let a tranny shop bleed it now to see if they can make it better.