Need help with diagnosing clutch problem

[tlerma909]

Around 4 weeks ago the clutch in my 94 4x4 XE began to lose pressure slowly, after a couple of days the clutch travel was only a couple of inches total between its top spot and the floor, thus making shifting very hard (with almost no pedal). I found that I could open the clutch master cylinder cap, vigorously pump the clutch and the pressure would return, but by the end of the day the clutch would lose pressure and droop towards the floor. There had been no noticeable loss of fluid in the time when I was doing this.

After reading some internet posts on solutions, I decided to replace the master and slave clutch cylinders to try to fix the problem. I did so and bled the system and in taking off the old master/slave cylinders, I found that (to me at least) they appeared to be totally trashed and worn out. After bleeding and getting in to take a test drive, I found that the clutch behaved as if it was partially engaged while driving with no pressure on the clutch pedal.

Basically after shifting, completely removing my foot off the clutch and hitting the gas, I get very high rpms and feel very little torque. Imagine driving in gear with your foot halfway engaging the clutch. That's how it feels to me. I drove it around for an hour and came back and re-bled the system and it didn't make any improvement.

I did some further reading and found a post about removing and bypassing the clutch damper on the passenger side firewall, which I did this morning. Of course, I then had to re-bleed the system, and after making damn sure I wasn't getting any more bubbles out of the slave cylinder drain, I hopped in and tried it again. There was a slight improvement, but it pretty much behaves the same. If I give it a lot of gas, I just get really high rpms and the car doesn't move much, again feeling like the clutch is pressed in some when its not.

It pretty much behaves just as before, with the clutch feeling like it is engaged even when the pedal is not being depressed. Any idea what the problem is? Could my clutch just be hosed and need replacing? I had read somewhere that if the vehicle stalls out when you have it against a curb that the clutch should still be good (which mine still does) but I really have no knowledge to know if that is true or not. I hadn't had any clutch issues until the pedal became spongy and lost pressure, and to me it was clear that both cylinders were worn out and needed replacing. Is there anything else I can check to try and get this fixed besides having a whole new clutch put in? Has anyone experienced a similar problem with their clutch? I can't say that I've ever experienced a clutch go completely out on any of the manual transmission vehicles I have driven before, what does a clutch normally start to do when it begins to fail? Sorry for the long and drawn out post, but I wanted to be thorough in hopes of finding a resolution other than changing the whole clutch out. Thanks in advance for anyone who takes the time to read the post and respond!

[PathyAndTheJets]

Did you bench bleed the master? If not you may still have some air stuck in there.

 

For checking the clutch I've always been told to stomp it to the boards and row through the gears quickly. Like 4th gear at 20 mph and watch to see if your RPMs rise faster than you're accelerating.

Edited January 19, 2016 by PathyAndTheJets

[RF600]

Bleed the clutch again. Did you check the hose? Maybe there is a problem with it leaking. Are you actually losing fluid?

 

Clean everything off with brakekleen or something like that. Pump the clutch a few times and see if there are any leaks.

[RIPB.88]

+1 to bleeding clutch again

[Precise1]

Yes, to bench bleeding the MC, it does sound like there is a considerable air bubble, and can make it act like you describe.

 

The slave cylinder presses against a fork that goes through the bell housing, and pushes on the throw out bearing/pressure plate to disengage the clutch. Are you certain the slave cylinder is exactly the same with the same distance of throw/travel from the mounting bolt holes. Hopefully you ccan compare it to the old part (I never throw away old parts until I know everything is working properly).

Without doing anything else, if you crack the bleeding nipple on the SS, does any fluid come out, like there is some residual pressure? Does the slave cylinder relax or retract?

Most importantly, once you have done, this is there a little play in that fork pivot, like it isn't under load?

 

Also don't drive it like this unless you want to risk glazing the flywheel and clutch plate.

 

B