nävəs

Hey Guys!

I'm very thankful to find this forum! This is my first time to post.

This issue involves the hydraulic clutch system on a 1994 Cherokee SE.

The clutch master cylinder was leaking, causing issues, so we decided to replace the whole hydraulic assembly, bought as one part, master, slave and line included, pre-filled, pre-bled.

After the successful installation and testing, it suddenly occurred to me that I had forgotten to remove the little plastic straps that keep the rod pushed into the new slave. I had thought those little straps were for the part transportation only. Of course, NOW I know that I had done nothing wrong to begin with, that the straps were SUPPOSED to remain there, even for installation.

But I did not know that yesterday. Mind you, I know very little about the workings of the 'innards' within the dark chambers of that transmission that I felt I had probably just violated with plastic debris. Even though everything was now working great, I just wanted to make sure that those little snapped straps wouldn't in some way negatively affect the operation of my friend's vehicle.

So, without much forethought, I went ahead and grabbed the socket and the wrench. Once the slave was unbolted, I had my friend go get a knife while I held the piston back. I then cut the little snapped straps from the tip of the piston and bolted the thing back on.

When my friend tried to test the clutch ... almost no resistance from the clutch pedal.

Long story short, when I then checked the fluid reservoir (the first time I had done so on the new unit) it was almost completely empty and it ALSO looked dirty. THIS is where the mystery comes in! It was obvious that air, and possibly some kind of contaminant, was introduced into the line out of the process of removing and re-installing the slave. I suspect the piston of the slave ended up extending out enough to reduce the fluid level in the master reservoir to the point where it was completely empty. That explains how air got into the line, but it does not explain how the fluid got dirty in this brand-new, sealed assembly.

I completely freaked! My first thought was that the slave piston, perhaps, did not line up with it's intended mating point when re-bolted to the transmission. I wondered, then, if maybe the piston on the slave had come all the way out within the chamber of the transmission. My guess was that fluid was going to be EVERYWHERE upon the next removal of the slave, but, thankfully, that was not the case. Upon removal, there was absolutely no evidence of any leakage of fluid at the slave end at all.

I re-installed the slave, making damn sure this time that the piston lined up with the lever inside the transmission. I then went inside the house and found a new, sealed container of Dot 3 under my kitchen cabinet (unneeded from a previous brake job), half-filled the master reservoir, and then slowly pumped the clutch to bleed, which made the new fluid dirty. I used an old turkey baster to empty the dirty fluid from the reservoir, used a clean cloth to wipe it out, and repeated this process about four times until the fluid seemed to stay clean. However, the slow pumping did not seem to be removing the air from the line. I came in the house, found this forum through Google, saw a thread on bleeding the clutch, and settled on trying the rapid-pump of the clutch pedal method.

This SEEMED to fix the issue. Took it around the block, it seemed to be working great. My friend went home.

Heard from my friend when he got home, and it's now all squishy. Of course, there's still air in the line. This particular system has no bleed valve, so I would think the next step in trying to rectify my disaster would be to manually bleed the line by removing the slave again, pulling it down as vertical as possible, and then pushing the piston completely in with the thumb, repeatedly, in hopes that all the air will be removed. This was another suggestion on how to bleed such a system from the same thread I had look at before, the one that suggested the rapid-pump method.

So, after all that mess of explanation, my questions would be as follows;

• How did the the fluid get dirty in a brand-new, sealed unit?
  
• Am I on the right track by continuing to try to bleed the system?
  
• Did I possibly do damage to the slave unit when the slave piston, apparently, at some point under my quackery of 'do-it-yourself-ism,' hyper-extended??
  
• IF the piston hyper-extended, is it possible that the 'dirtiness' of the fluid was the result of the fluid coming into contact with an area within the slave cylinder that it was NEVER supposed to come into contact with?

Thank you in advance for any suggestions. : )

Chuck.

DFlintstone

Really? No bleeder? Let me guess, it's a plastic line? On a brake slave with a seized bleeder I've loosened the nut on the line....

Air can and does work out on it's own. As far as crap on a new sealed system...I suppose I'd talk to the people I bought it from.

Welcome to the forum! Hopefully someone more familiar with your that 94 will come along. (filling out the info is recommended)

highmileage

Most of the hydraulic throwouts' work the same. You do not have to always bleed the system, but a lot of pumping is involved and make sure you are depressing the pedal ALL the way. If it is not getting depressed all the way it will stay mushy for a while.