MrEracer

Some cars have this problem some don't. I think I have discovered the reason/problem. While installing the clutch peddle assembly on an A4 to MN6 conversion I noticed that the clutch peddle would be forced to the floor by the return spring with no hydraulics connected. Pull the peddle up and it returns in the expected way. Turns out that the return spring goes 'over center' when near the bottom of the travel and holds the peddle down. The only force available to overcome this are the springs in the pressure plate that apply a return force on the throw out bearing (slave cylinder). At high rpm they may not have enough mechanical advantage to do the job. I think this is a design problem that is aggrivated by manufacturing variation that can make this a problem for some and not others
I've contemplated replacing the coil wound return spring with a direct pull return spring but I didn't want to re-invent the wheel. I have decided that the easiest and simplest solution is to place a limiter block on the floor under the clutch peddle. This will prevent the clutch return spring from going 'over center' causing the dreaded 'clutch peddle on the floor' syndrome. It shouldn't take more than a one inch spacer block under the clutch peddle and this is not enough to cause disengagement problems... Try it and let us know how it works...
Shirl
SDRE

JoeyG

Cool to know :thumbs:

However reminds me of my Big block '85 Ford 1 ton with Hydrallic clutch. Ended up replacing the return spring with hooked end coil springs just as you described above to cure the exact same problem. :skep:

NEPTUNEBILL

I removed the springs long ago and it had no affect on the sticking problem its better without the springs all together, but not the only reason the clutch sticks to the floor, I think its a hydr problem..

66ImpalaLT1

This is the best explaination I've seen to date. Do you still remove the restrictors from the hydraulic line?

Eric

Phil97SVT

I recently removed my spring and am very happy. Someone told me that LPE has been removing their springs for some time now. Definitely makes sense.
Phillip

z0sense

With or without the spring the problem was still there for me. It may be some people's problem, but not everyones.

This has been posted before as a possible problem, and many have tried to correct it with the removal. Most everyones attempt failed:(

Still a cheap and easy option to try first!

WRK CAR

:iagree: Check your pressure plate.

chuckster

Maybe on some cars this could be an issue.. However I can tell you without a shadow of a doubt... It is mechanical and only occurs during hard shifting at very aggressive Throttle positions... i.e WOT and REDLINE...

I tried to duplicate my problem in the driveway by masing the clutch pedal down and up as fast as I could for like a minute straight.. NOTHING!

Took it for an aggressive romp and BAM...Stuck on the floor and then popped back up and slapped me in the foot..

There is a binding or something that keeps the pressure plate fingers from pushing the throwout bearing from pushing the fluid in the slave back up.

What ever....The assembly must be replaced and retorqued properly... My problem has gone away..


Also the clutch restriction for solving this problem is a snipe hunt....I did the drilled out mod to help this issue and it did nothing to solve it..

It did however make the clutch action a little faster.. You could actually feel the clutch engagement shocking the drivetrain upon an aggressive pedal lift..

JMHO from a person who hunted this problem down for 2 years.. ;)


My personal opinion is that the Stock Slave SUCKS.. Everything has to be PERFECT for it to work good.. I bet as soon as there is an aftermarket slave available our problems will be solved for good..

[Modified by chuckster, 10:24 PM 11/16/2003]


[Modified by chuckster, 10:26 PM 11/16/2003]

ICUALL

Suffered this aggravation for almost 3 years now on my 2000 Coupe. I had it to the dealer numerous times and they said it was air in the system. After bleeding it was fine for a few days and would return. Turns out there is a dealer "alert" on the issue and the problem can only be resolved by replacing the clutch Master and Slave Unit. It also identifies a possibility of damage to the clutch and pressure plate.
The dealer replaced the master and slave unit but charged me for a new clutch assembly, pressure plate and Flywheel.. I am in the process of complaining to GM as the problem has been happening since the car was new. OF course the fact that I had it to the dealer 4 or 5 times without a fix doesn't count. At 92,000 miles the clutch was "worn out" from use according to the dealer. Did not explain the need for a $500 flywheel replacement... :mad :mad :mad :mad :mad

chuckster

Ya know you may have another point here Shirl...But more than the just the springs you talk of.... If you don't need to go all the way to the floor to disengage the clutch.. Then why overstress the Slave by hyperextending it.. Maybe this is the cause that starts the whole thing in motion..Once the slave starts acting up it is pretty much shot after that... hmmmm Limit the clutch pedal travel... this is interesting..

FRC Tom

After 5 GM clutches replaced under warranty I can tell you it is not the hydraulics or the pedal spring, it is the self adjusting pressure plate that gets stuck under high rpms.
My last GM clutch was installed in June, within 3K miles it started the sticking pedal for the 6th time.
I replaced the clutch and pressure plate only (no hydraulics) with a Spec 3 and no more sticking pedal. Still using the master and slave that was on the car with the bad pedal.

chuckster

Good point Tom..I thought I remember seeing people with aftermarket clutches having the sticking issue...I just assumed the only thing left was the Stock Slave.. They must have been using the original Pressure Plate too? :eek:

MySea6

when talking about the clutch pedal issue, MTI Jayson showed me several used factory pressure plates where the return springs were either completely dead (annealed from heat) or had little to no spring pressure left.

Stock Man

Something to watch out for. Thanks! :thumbs: :seeya

C5-VERT

The funny thing is the SPEC III is based on a self-adjusting PP. I agree that the stock setup is the culprit b/c I had severe sticking clutch pedal but after my SPEC III install it has never happened again for over a year now. No question the spring was NOT the problem for me. Thanks for trying to help everyone though. :cheers: