My Clutch Pedal went to the floor at the track

[FasNuf]

Originally Posted by Gbland60

How many track miles and total do you have on it.
Known issue being the brake pressure exceeds the slave pressure needed so inturn the weakest link goes first under extreme use????

I thought the brakes and clutch were only linked in the reservoir? There shouldn't be any appreciable pressure in the reservoir.

[FasNuf]

I bet when he disassembles the clutch and slave, they'll be all kinds of clutch dust muckin up the works. This dust is known to get past the slave seals as well as contaminating the fluid.

[RankSS]

I bet the plastic bearing support in the slave melted. You need the billet bearing support that monster or Tick can supply with a new GM slave.

[Gbland60]

Originally Posted by FasNuf

I thought the brakes and clutch were only linked in the reservoir? There shouldn't be any appreciable pressure in the reservoir.

This is true. Hum

[Jayjellyfish212]

Just a heads up... I had my clutch pedal stick to the floor once. Happened only once. Before this happened on mine I already did the clutch reservoir mod and fluid upgrade to motul 660. I did that mod about a year prior to my clutch pedal sticking that one time.. I say this just so everyone can see that this clutch pedal sticking crap definitely has not much to do with the fluid or reservoir.

The day my pedal stuck it all came back to normal after the car cooled down in engine bay. About a week later I decided to do the Tick billet sleeve mod and speed bleeder. Since I had it all apart I just upgraded the entire clutch to a McLoad twin disc and put a new slave cylinder in to. I then put the LPE return spring on the clutch pedal to. Never had any issues since then and I am very hard on the car usually even when not at the tracks.

I’m leaning towards upgrading the master cylinder next just so I know the entire system is upgraded. I know that clutch pedal sticking once it happens to ya it just sucks and ruins your day.

[69L48Z27]

Originally Posted by pat_t

FYI - My car has a misadjusted clutch from new. My symptoms were slipping clutch not pedal feel, but removing the gearbox and correctly re-adjusting the preload on the fingers solved the issue.

While the gearbox was off I put a remote clutch bleed in.

Since then I've used Motul 660, replaced fluid regularly and it has been fine, (7000 hard miles including lots on track).

Your issue may not be related but if you end up having the gearbox off, definitely get the clutch pre-load checked

Pat_t - Is there any kind of video or post that describes that adjustment? Curious if you do it without removing the trans. My clutch has always felt a bit high on release point but never slipped.
TIA

[Gbland60]

I made an era. It was 32.25. Mm. Not 11.5. On the wheels I'm going to sleep now a month recharge my PCM.

[dardbrown]

The car has only 10800 miles on it and I was the first to put in on the track for only 5 reasonably easy laps just getting to know how it handles and relearning HPR. I did some more testing and I think the clutch slave cylinder bleeder got loose. Because laying underneath I watched to fluid squirt out the side of the bell housing where the bleeder is. I got a mirror and saw that there is no cap on it.

[dardbrown]

Is there a special tool to tighten/loosen the clutch bleeder? I tried a small socket and an end wrench. It was futile! I ordered the Tic remote bleeder and the separate reservoir. How in the world do you install it? Do I have to drop the tranny?

[dardbrown]

Originally Posted by dardbrown

I flushed out the DOT3 with DOT4 brake fluid in my brake system. But I didn't do anything with the clutch. On the sixth lap at HPR the pedal stuck to the floor and stayed there. It cost me a boat load of money to have it towed back home. One of the Corvette guys said he had the same problem and put MOTUL 660 after flushing out the system. Any ideas why this would happen? The brakes worked fantastic.

Originally Posted by 1970judge

What fluid was in it specifically?

I was using the blue type 200 stuff.

[dardbrown]

Originally Posted by MX621

Miles? Mods? Stock clutch?

10800 miles, no mods just Dot4 fluid, stock clutch

[FasNuf]

Originally Posted by Jayjellyfish212

Just a heads up... I had my clutch pedal stick to the floor once. Happened only once. Before this happened on mine I already did the clutch reservoir mod and fluid upgrade to motul 660. I did that mod about a year prior to my clutch pedal sticking that one time.. I say this just so everyone can see that this clutch pedal sticking crap definitely has not much to do with the fluid or reservoir.

The day my pedal stuck it all came back to normal after the car cooled down in engine bay. About a week later I decided to do the Tick billet sleeve mod and speed bleeder. Since I had it all apart I just upgraded the entire clutch to a McLoad twin disc and put a new slave cylinder in to. I then put the LPE return spring on the clutch pedal to. Never had any issues since then and I am very hard on the car usually even when not at the tracks.

I’m leaning towards upgrading the master cylinder next just so I know the entire system is upgraded. I know that clutch pedal sticking once it happens to ya it just sucks and ruins your day.

So I understand that the plastic sleeve can melt causing the pedal stick issues and the billet sleeve is a fix. The reservoir is still a great idea to avoid cross contamination of the brakes and clutch systems. Cheap insurance.

[pat_t]

Originally Posted by 69L48Z27

Pat_t - Is there any kind of video or post that describes that adjustment? Curious if you do it without removing the trans. My clutch has always felt a bit high on release point but never slipped.
TIA

You definitely need to pull the trans. You need a press:

https://www.corvetteforum.com/forums...djustment.html

The clutches are self adjusting but can only adjust "out" to take account of friction plate and flywheel wear over time. If they are too far out when installed then there is always some load on the fingers, and the clutch capacity is reduced (hence slipping).

Following the procedure in the GM service manual solved all my issues, and the pedal feel is good with bite point in the middle of the travel where it should be.

If you want to get deeper into self adjusting clutch tech, I found this PDF from LUK who make the LS7 clutch.
https://www.repxpert.com/en/mediadoc...AC-TecBr-PC/en


Hope it's of help
Pat

[69L48Z27]

Originally Posted by pat_t

You definitely need to pull the trans. You need a press:

https://www.corvetteforum.com/forums...djustment.html

The clutches are self adjusting but can only adjust "out" to take account of friction plate and flywheel wear over time. If they are too far out when installed then there is always some load on the fingers, and the clutch capacity is reduced (hence slipping).

Following the procedure in the GM service manual solved all my issues, and the pedal feel is good with bite point in the middle of the travel where it should be.

If you want to get deeper into self adjusting clutch tech, I found this PDF from LUK who make the LS7 clutch.
https://www.repxpert.com/en/mediadoc...AC-TecBr-PC/en


Hope it's of help
Pat

It is, thank you!