I would like to tap into the C5 braintrust. What do you think?

Symptoms: very difficult shifting into reverse (lock out switch works fine)
mild difficulty shifting into random forward gears

Problem evidence: 1- air bleeds out of remote bleeder line and can never be bleed air free. I tried slow pedel bleed and fast forceful bleeds. 2- I used to be able to bleed air free even after the hardest time to bleed after a clutch change several years ago.
3- Even after bleed shifting is not great because still air in there. Shifting is best when cold. Heat makes air expand and shifting increases in difficulty but peaks and never gets any worse. 4- Even tried sucking air out top with stopper method. 5- repeat bleed attempts cause frothing of fluid and frothy fluid to be bleed.

Diagnosis: either air leaking in the slave seals or air coming in master seals.

Best guess: my problem is the master cylinder. I think seals are bad in it. Why? 1- frothy fluid 2- if slave leaky then my guess would be I could bleed it clean then it would get worse with use. 3- shift difficulty reaches a peak point of difficulty and "never" gets any worse.

So what do you guys thing? Any clutch hydraulic experts out there?

 

I would think any seals that could leak air in, would leak fluid out. Are you losing fluid? Did you check under the plunger boot on the master?
I I had your predicament, I would change the master. Much less work and not real expensive.
Just my 2cents.

 

ive asked trans questions and get hardly a response. not upset or anything just saying, so I started diagnosing myself. ive changed the shifter bushings which greatly helped and changed to amsoil fluid. next is bleeding and changing the clutch fluid and then clutch master cylinder. good luck but lease keep me updated

 

And start saving for a slave cylinder replacement.

 

Could be easier than this. If you're losing fluid, refill, drive, let it drop, refill again, drive some more, then jack the car up and open up the master cylinder closeout pannel in the fender to get a look at the master cylinder. While the car is up, look under the car at the bell housing on both sides.

You should see fluid discharge on one of those areas. If it's on the bell housing and the master is dry, don't waste time or resources changing the master, because it's the slave that's bleeding out.

 

Not to hijack, but what goes bad in the master? Is it a mileage or age issue when they start to go bad? I have a 97' with 62K miles. About to swap in a NEW 12mm Torque Tube and Monster Level 2 clutch with new slave, pilot & throw out bearing. Contemplating whether I need to replace the master as well.

 

I was slowly losing clutch fluid and couldn't find an external leak. Over the winter, I pulled back the carpet in the driver's footwell...and it was wet. My master had been leaking from the seal around the push rod. If I was doing a clutch job (or suspected a clutch issue) on one of these cars that is 10+ years old (all of them) I would look at the master first unless there was a smoking gun (signs of external leakage) that pointed to the slave.

 

UPDATE:

Riddle me this: How can air seem to find its way into a closed clutch system when there are no detectable leaks?

I seem to have micro bubbles I just can't clear from the remote bleeder line. If I wait they will coalesce into a nice larger bubble. Then when I bleed that bubble its like the bleed action froths the fluid even after 1 pump and the 3 or 4 to bring the pedal back and the microbubbles are there again. Being unable to completely bleed this line is driving me crazy. I changed my master thinking a bad master could froth fluid despite having no leaks and nice clutch action. I have successfully bled this clutch for every raceprep for the last 10 years so technique is not an issue.

Any ideas??? The only thing left is the slave but it is a pain to change. I hate dropping the whole tunnel guts.

I always hated the remote bleed line. The bleeder at the end is sort of coarse thread so when you crack the bleeder you get wet threads. I reemmber reading once that these bleeders are kludged together, I.E. a bleed screw stuck in a AN3 line with a poorly cut female seat for the bleeder and the lines are then a bit wonky. bleeder to line fit so badly that there was some kind of brown sealant stuff that was semi-permenant on the threads. brake calipers don't have that. My bleed line is 10 years old. I wonder if it is at all possible that upon pressing the clutch pedal and opening the bleeder that the fluid rushing out is creating a small venturi and sucking air at the threads making microbubbles fooling me into thinking the air is down by the slave?

I just don't see how air can enter the system and I get no leaks and no fluid loss. Opinions?

 

I like your theory of air rushing in past the bleeder screw, but if that can happen, there should be a leak at the bleeder during normal driving. Mysterious.

 

Nope when the bleeder is shut nit air or fluid can pass. I'm thinking more of a venturi effect drawing air in when the bleeder is cracked open and bleeder is wobbly in the bleed line.

 

pm'ed

 

I knew my problem was the slave because of the puddles underneath the car.

 

fatbillybob, did you figure it out? What bleeder do you have? Is this an isolated problem or is it common? I have a Monster clutch and one of their bleeders and am curious if I should expect issues as well???

 

A molecule of air is smaller than a molecule of oil therefore you could have a one way leak. I think your venturi effect is plausible too. Can you redo the end of the bleeder? Maybe the dope on the threads has dried out and cracked.

Dumb question: Have you done a shifter alignment lately? May be time to do one. Maybe you have two separate issues. If I had to start doing a part swap, I'd certainly opt for the master cylinder. Much easier to perform and not terribly expensive either.