Ferdzz

Hello All,

I've been perplexed for the last few months with this clutch problem. Here are the symptoms:
Drive about 100-120 miles and clutch starts to become at a lower engagement point, finally after 150 miles clutch pedal is nearly to to floor and can not engage into a gear.
Bleed the clutch with very little air in line and it goes back to normal, until I drive as above.


No fluid leaks
Changed the following parts already:
Clutch Slave x2
Clutch Master
Clutch (rubber) soft line going into slave


I do have a issue with the clutch release bearing, since I can feel a vibration in the clutch when slightly depressed.
The clutch has only 9K on it, which was switched to a stage 2 clutch and lightweight flywheel.

Could it be the something internal inside the clutch, I don't want to take it to the shop and it is not the clutch.

I am feeling frustrated with situation, and thoughts on what it could be is appreciated.

Thanks,

Ferdzz

vandersmith

Bad slave cylinder.

charlieaf92

Did you replace the release bearing and pressure plate when you did the clutch and flywheel?

speed rII

I just re read your previous post about this problem again.
Pressure bearing vibration got me thinking about foaming in the clutch fluid.

If you feel the pedal vibrate, the fluid will vibrate back and forth allso. This will foam the fluid and it might allso get it super hot. Even to boiling point inside the slave. This can even cause cavitation if the amplitude is fast enough.

This will allso happen if the clutch is not pressed, becouse the slave has spring that keeps the pressure bearing against the pressure plate.

dcdrechsel

Speed RII hypothesis could be right .If you bleed the system and don't drive the car for a few days -does the clutch function correctly ?I had a similar problem and ended up replacing slave -master cylinder and flex line to slave in sequential order .The final fix was bleeding almost two big bottles of fluid to get the air out with a pressure bleeder .The difference in my situation was that the pedal would go soft after sitting overnight .

Ferdzz

The release bearing, IMS, were also replaced during the last clutch replacement, about 9000 miles ago.
I am on my second slave cylinder (FTE) brand which has the same symptoms as the first one I changed.

I have replaced the clutch fluid so many times when I bleed it and it looks good. If it is the the release bearing is vibrating which it is, can this happen when the car is on highway driving for many miles?

Ferdzz

Do think its a internal clutch problem ie.. release bearing, clutch springs etc... or another slave or master cylinder. I dont want to drop another $2000.00 on a clutch job just to find out its something external to the gearbox/clutch.

speed rII

Yes, the release bearing rides against pressure plate all the time.
Even when the clutch pedal is not pressed. So this litle movement is allways there, when the enginine runs.

Your LWFW might allso be warped or bent.

Jmrjimbo

Have you checked the pivot for the release fork?

relinuca

I suspect there are multiple causes here. For sure, air is entering the release system some how/some where. Also, I'm suspicious about that LWFW and pressure plate combo.

Pulling the trans is probably a necessity to fully identify the cause(s).

relinuca

Ferdzz

Hi all,

Here is another observation I forgot to mention:

During my bleed operation with the motive power bleeder charged up and clutch pedal all the way down with a piece of wood hold it down.

When I turn the bleed screw, a little bit of air (air bubbles large 4-5 ) can be seen in the clear hose going into my catch basin.

At the same time when I turn the bleeder screw, I can hear the clutch release and it seems that the slave has pushed back to its full retracted position.

What seems to happen is that when I drive the 100-150 miles the clutch slave piston is increasingly becoming extended out, and not returning to it's full retracted position (clutch pedal all the way up). But when I bleed the clutch it goes back to normal position/travel.
(see pix.)



Any thoughts???

speed rII

How did you confirm this? I dont think that its possible to see the clutch fork or slave rod.

If you push the pedal (clutch open/slave out) and open the bleed screw, pressureplate will push the slave in/ clutch closed.

Schnell Gelb

Ferdzz,
I hope you kept your old DMF ?
Jake has written that the LWFW is about the worst possible mod to an M96.
But to be fair, I wonder if the vibration you mentioned is caused by a few weak fingers on the pressure plate?

Noz1974

It does sound like air is getting in especially if you can bleed it and it goes ok, I think if it was clutch internals it would be all the time, what about the brake system leaking air into the system as they are both linked is that something you could look at?

Ferdzz

speed rII,

I can not confirm this visually, but only through circumstantial observations of what is happening.