Another Clutch Problem...

[Hobbes]

2000 996 C2.

 

About a week ago, the clutch would engage, but not return to normal position.  I was thinking air got into the line and I decided to bleed the line.  I pressurized the reservoir, depressed the clutch and opened they hydraulic slave bleeder valve.  When I did this, a little bit of air came out, but fluid trickled into the collection tube.  Now, the clutch goes to the floor and will not recover to normal position.  I can manually pull the clutch pedal up, but when I depress the clutch, the pedal springs to the floor and does not recover.  when the hydraulic line is pressurized, not fluid comes out of the bleeder valve.  The only time a spurt of fluid comes out is when I manually pull and push the clutch pedal (clutch pedal stays depressed).

 

I am thinking its the hydraulic slave, but it could also be a bad throwout bearing/fork.  Is there a definitive way to determine which one it might be based on my description above?  There wasn't any clutch slippage or problems with the clutch until recently when the clutch pedal would not recover to normal position.  I did notice a small hydraulic fluid drops under the 996; there are not cracks or any other leakage spots.

 

Thanks,

Ken

 

[Loren]

Did you follow my DIY?

 

 

[Hobbes]

Loren - yes, I did.  I'm going to try it again tomorrow.  When I got to step 2, there was some air that came out and a very small amount of fluid, but nothing continuous in the collection tube.

[Loren]

Trying again is the best move at this point. If that does not help it could be that the 17-year-old slave cylinder is leaking back. In that case, you likely need a new slave cylinder.

Also, check the pedal mechanism itself for binding or sticking.

[Hobbes]

Thanks Loren.  I did check the pedal mechanism and nothing seems to be binding or sticking. 

 

A follow up question:  When I use the pressure bleeder (Motiv), depress and hold the clutch pedal down and open the slave bleeder valve, should the positive pressure push/force fluid through the line from the reservoir to the bleeder to have a constant flow?  This is what I expected to happen, but I did not see it.

 

 

[Loren]

Yes, it will not be fast since the clutch valve opening is small. Motive pressure should be just under 20 psi.

Keep the pedal depressed during the whole time the valve is open. Once the valve is closed and tight manually pull the pedal back. It may take a few pedal actuations for the pedal to feel normal.

 

[Hobbes]

Thank you Loren.  I'll give this a try when I get home.

[flatjoe]

I had same problem. It was cracked pressure plate. Your problem seems to be the same.

[Hobbes]

Thanks,

 

It looks like I'll be removing they hydraulic slave and checking it out.  I followed the clutch bleed DIY and I wasn't able to bleed the thing after about two hours.  I applied about 18 PSI positive air flow from the reservoir side and nothing but a couple of drops came out of the bleeder end with no change in the clutch pedal feel.  It's acting like the slave arm that rests against the fork inside the bell housing is non-existent.  I started the car to see if I could get it into gear with the clutch to the floor, and it didn't happen.

 

Thanks flatjoe - I'll take a look at this too as a cause.

 

More to come on this...

[Hobbes]

Update:

 

I removed the slave cylinder last night and saw I had hydraulic fluid on the arm side of the cylinder.  It looks like I have a bad slave.  Since I did not see any hydraulic leak on the ground (or very little), I imagine it leaked into the bell housing and the leak drops came from where the bell housing bolts up to the engine.

 

Leaking:  IMG-4537.mov

 

 

Edited July 20, 2017 by Hobbes

[Loren]

In the old days, we would rebuild those with new seals and a little honing to remove any rough spots.

Now I think it is best to just replace it - since there have been at least 6 iterations of the slave cylinder.

 

Here is the latest rev:  997 116 237 04 Clutch slave cylinder -- US MSRP $163.89

 

 

 

[Hobbes]

I can send you my old one if you want to polish up on the skill and rebuild this one, otherwise I'm sending it to the dump.  Thanks for the part # and the price tag.  I checked Sonnen and they have it listed for $118.  Not a bad savings difference.  It should be here tomorrow or Saturday.

[Loren]

The problem is finding new seals only - so just trash it.

Looks like you are on your way to driving again

[Hobbes]

Haha - yeah. A lot of effort for something that is easily and relatively cheap to replace; maybe I can gut it and get something for the aluminum.  Appreciate the help and insights.