Clutch won't disengage - no leaks?

Was out playin' in the mud today and the clutch stopped fully disengaging.

First started before we even got to the lake. Just pulled up the road entrance and couldn't downshift. Powershifted down and stopped to take a look. Couldn't find anything obvious, so I started it back up and it worked fine.

Bombed around for a bit, ended up having to tow my buddy home cause his truck had the exact opposite problem (clutch wouldn't engage after I pulled him out of a puddle).
My XJ though, pulled him to the highway without issue, then as soon as we got to the higway (same place it started the first time) the clutch died on me again.

We did a quick bleed of the slave. Buddy pumped and held, I opened the bleeder, got sprayed in the eyes (was pretty high pressure), torque back down, and no change. I just drove home 70km through rush hour traffic, powershifting the whole way. Clutch started working again sporadically, but I tried not to use it unless absolutely necessary.

So looking around, there's no fluid leaking externally as far as I can tell. The pedal feels pretty much normal, there's no air in the slave. What's goin' on?

haha your car gave you a facial.

But anyways, what are you doing at a standstill shoving it into neutral?
I had a problem like this on another car before. The springs in the pressure plate broke and wasnt allowing the clutch to disenguage.
So I would start by taking a peek in the inspection hole (do manual xjs have one?)

Otherwise it could also be a throw out bearing

I thought power shifting was what the boy racer crowd did on their Honda Civic? Keeping the gas on the floor when shifting.

That was my impression, you can get by without the clutch by rev matching, I'm assuming that's what he's referring to, bit of a rough ride though

I heard the term "powershifting" used way up northern Alberta long before we'd ever heard of "Civic" .. let's call it rev matching though, and rev-matching, done properly, isn't at all jerky.

That said though...
I've never noticed an inspection port.

I did however notice that the slave cylinder seems a bit loosely bolted to the bellhousing, so I'm going to investigate that this afternoon.

Other than the slave not being bolted on tight enough, the only things that make sense to me are a bent clutch fork. My foot is going right to the floor, with no abnormal resistance, so as far as I can imagine, this means that the TO bearing is being pulled back as far as my foot will allow, thus it must be something between my foot at the TO bearing that isn't pushing far enough. I'm not getting how a busted spring on the pressure plate would cause the clutch to NOT disengage to the point that I can't stay in gear with the clutch down at a light. I could imagine a little scraping, but not so much that it would lurch the Jeep forward while cranking. Am I missing something?

*edit* As I've never actually pulled apart a clutch, I didn't know that the pressure plate fingers were pivoted from the TOB to the clutch plate. I always thought the TOB pulled BACK away from the clutch to disengage, rather than pushing FORWARD into the inner side of the fingers, thus causing the outer edge to pull back. Now I can't figure out how the clutch fork works, as it is pushed forward by the slave, but I thought it was on a pivot, which would mean it would pull the TOB back. wtf? I must still be missing something. No pivot on the fork?

Well either way time to break it apart and look at it.
Something is broken in the assembly somewhere and only way to figure it out (unless there is an inpection hole) is to get it apart!

x91evo said:

Well either way time to break it apart and look at it.
Something is broken in the assembly somewhere and only way to figure it out (unless there is an inpection hole) is to get it apart!

Click to expand...

Yea, as is usually the case. Just a PITA with no driveway/shop, working in the rain on the gravel/mud/dogpoo.

Ahha thats horrible! Hopefully the dog poop isnt to stinky
Good news is the part shouldnt be too much money to replace! just time

So pulled the slave, everything looked good. Can't get a full picture in there, but didn't see anything broken.
Put it back together and did a few second clutch burn (till I could smell it) and the problem went away.. again... Drove around for a few minutes, intermittently the problem came back but now I can't make it fail again. Short of pulling the transmission now and hoping to find something obvious, I can't think of anything to do. Can a clutch plate really get forced engaged with a bit of dirt/debris in there, yet intermittently still work?
I'm wondering if I first noticed the problem because the clutch was dry, then when we hit the mud, it all loosened up a bit, then after towing my buddy to the highway, it dried up again and started to stick?

I guess the mud could have dried up to enough of a solid mass, thickness, to fill the clutch to plate gap?

But get under the dash and check the clutch peddle assy for any sideways movement when pressed to the floor. Several of us have had them slowly fail there and cause the same problem!!!!

Lastly an air bubble in the rear of the slave cyl is nearly impossible to get out, and will feel right on the peddle, but also not work the pressure plate open. They are a PITA to bleed.

Ecomike said:

I guess the mud could have dried up to enough of a solid mass, thickness, to fill the clutch to plate gap?

But get under the dash and check the clutch peddle assy for any sideways movement when pressed to the floor. Several of us have had them slowly fail there and cause the same problem!!!!

Lastly an air bubble in the rear of the slave cyl is nearly impossible to get out, and will feel right on the peddle, but also not work the pressure plate open. They are a PITA to bleed.

Click to expand...

Thanks dude. Ecomike always to the rescue.

So how can I verify the slave is bled properly? 5x didn't seem to change anything. I hate to just throw money at the problem until it goes away, by installing a new master/slave assembly, but they're relatively inexpensive...
Anything I can check to verify?

Well check under the dash first. My problems with bleeding may have been made worse by a failing peddle assy.

One trick I learned was to manually pull the slave all the way back after each bleed step by puling the fork all the way back.

The last time I bleed one, I just quickly pumped the hell out of it about 500 times as fast as I could, and got the fluid to foam. Did that 3 times about 3-4 hours apart, by myself, and that worked. That let the bubbles work their way back to the MC, to the top it seems.

I had to replace the MC, slave cyl, tubing line and repair the foot peddle assy on mine before it stopped giving me problems. While I was fixing one or two others, the 30 year old line finally failed, tube had rubbed against something and finally cut the line.

The master or slave could be "bypassing"--allowing hydraulic fluid to get past without applying pressure.

Try this: get a helper, take the top off the clutch master, and have the helper slowly apply pressure to the clutch pedal--if you get a fluid geyser replace the master cylinder and then see if the clutch functions.

joe_peters said:

The master or slave could be "bypassing"--allowing hydraulic fluid to get past without applying pressure.

Try this: get a helper, take the top off the clutch master, and have the helper slowly apply pressure to the clutch pedal--if you get a fluid geyser replace the master cylinder and then see if the clutch functions.

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Yipper. Tried this while on the trail. Master fluid level doesn't seem to rise at all when the pedal is pushed down.
Was going to try to push the clutch fork manually to check for proper disengagement, but don't have anything around I can use to get the leverage required. I'm tempted to stick something inbetween the slave piston and the fork socket to see if it's just an issue of insufficient movement of the slave piston. *shrugs*. Still trying to figure out how to verify the master/slave are bled properly. It's just too weird that it's intermittent, and pumping doesn't solve it.

So took the Jeep for it's first wash in a few years today. Clutch worked fine for about 15 minutes (on the way to the car wash) and then started binding again. On the way back it'd disengage most of the time, but then squeal for a second and try to jolt me forward, then usually fine again (at lights).

What should I do here? I'm leaving for holidays tomorrow early afternoon, so I don't have time to pull the transmission. I could probably get the master/slave replaced in that time, but I've no idea if they're the problem. Anyone strongly suspect one cause over any other?

Did you check what I suggested yet?

But get under the dash and check the clutch peddle assy for any sideways movement when pressed to the floor. Several of us have had them slowly fail there and cause the same problem!!!!

Click to expand...

Ecomike said:

Did you check what I suggested yet?

Click to expand...

Hrm... I did get under the dash to check the bolts were all tight, but totally forgot to check for any lateral movement. Where would that movement be coming from? The pedal mount?

The weld on the part that attaches from the peddle to the pin that sticks out into the clutch MC comes loose and the peddle assy flexes, wiggles/wobbles/bends instead of actually pushing the MC shaft the full stroke.

http://www.naxja.org/forum/showthread.php?t=1094128

http://naxja.net/forum/showthread.php?p=245844388

Ecomike said:

The weld on the part that attaches from the peddle to the pin that sticks out into the clutch MC comes loose and the peddle assy flexes, wiggles/wobbles/bends instead of actually pushing the MC shaft the full stroke.

http://www.naxja.org/forum/showthread.php?t=1094128

http://naxja.net/forum/showthread.php?p=245844388

Click to expand...

Aww hell. I should've thought of this. Happened to my old limited 90xj. I was having the occasional clutch disengagement issue but already had a replacement Jeep, so I sold the 90 to my roomie (did tell him about the clutch). A month later he lent it to his buddy who managed to break the clutch pedal off in precisely the way you described. This would account for the intermittent nature of my current issue. Unfortunately I'm just about to load the Jeep for the trip, so hopefully it holds up. Will use the clutch sparingly and check it out later today. Thanks Mike.