Clutch engagement point moved?

[Squilt]

One day while driving, the bite point on the clutch pedal suddenly moved much higher. Where it used to engage was pretty close to the floor but now it's right at the top. It still feels like it's engaging fully. But I'm worried it won't be if it happens again. Its been nearly a month with no noticeable change though. It happened during some highway driving. I think after accelerating from a stop.

Anyone experienced something similar or has a guess as to what it could be?

 

[macleanflood]

Mileage? Any service history aka when was the last clutch put in?

Two ways to do this...wait to get stranded somewhere or preemptively put a Luk clutch kit in.

Certainly check the master/slave hydraulic clutch... maybe pull the reservoir cap off and check the fluid.

Pulling the transmission and transfer case are pretty easy and straightforward in Jeeps. Easy weekend project.

-Mac

 

[hear]

Your description is very similar to when my slave went out, although I only had one drive left in mine when it happened.

 

[Squilt]

Mileage? Any service history aka when was the last clutch put in?

Two ways to do this...wait to get stranded somewhere or preemptively put a Luk clutch kit in.

Certainly check the master/slave hydraulic clutch... maybe pull the reservoir cap off and check the fluid.

Pulling the transmission and transfer case are pretty easy and straightforward in Jeeps. Easy weekend project.

-Mac

Still on the factory clutch. 150k miles. Just checked the fluid and it's fine. I'd suspect the clutch itself if it weren't for the sudden nature of it.

 

[Squilt]

Your description is very similar to when my slave went out, although I only had one drive left in mine when it happened.

Did you replace the master too?

 

[Chris]

Sounds exactly like what happened when my slave cylinder when out as well. Granted that was on a BMW, but same exact symptoms.

 

[Squilt]

I took off the slave and nothing seems weird about it.
This is the point it returns to after pushing the rod in

And this is how far it extends when pressing the clutch

It'll extend further after multiple pressed but that pushes the rod out.

 

[hear]

Did you replace the master too?

Yes, usually it comes as a set.

 

[machoheadgames]

When you reinstall the slave does it require decent spring pressure to seat it onto the studs? It should, because it pressed the throw out bearing up against the pressure plate in normal operation. I’m curious if somehow that relationship changed.

At 150K you probably have some wear causing the clutch fingers to be outward some which just pushes the bearing/fork against the slave more. Can’t think of why anything suddenly changed though.

One thing to know is that due to the throw out bearing riding on the pressure plate, the system actually needs less brake fluid as the clutch wears. Any chance you’ve reached a point where need to remove some fluid?

Also, does the pressure plate look okay from what you can see in the slave hole?

 

[hear]

I took off the slave and nothing seems weird about it.
This is the point it returns to after pushing the rod in View attachment 545888
And this is how far it extends when pressing the clutchView attachment 545889
It'll extend further after multiple pressed but that pushes the rod out.

This is not my area of expertise, but it seems like that’s not enough travel. When I installed my new one it had the rod sorta strapped in while drawn in. Then once installed, the first time you press the clutch it shoves the rod out & beaks the strap. I don’t see much difference between in & out in your pics, which is consistent with a low fluid condition.

But like I said, this isn’t my area. I would trust macho, but I’m also expecting him to tell me why I’m wrong about this.

 

[Squilt]

When you reinstall the slave does it require decent spring pressure to seat it onto the studs? It should, because it pressed the throw out bearing up against the pressure plate in normal operation. I’m curious if somehow that relationship changed.

At 150K you probably have some wear causing the clutch fingers to be outward some which just pushes the bearing/fork against the slave more. Can’t think of why anything suddenly changed though.

One thing to know is that due to the throw out bearing riding on the pressure plate, the system actually needs less brake fluid as the clutch wears. Any chance you’ve reached a point where need to remove some fluid?

Also, does the pressure plate look okay from what you can see in the slave hole?

Yes there's decent pressure needed to get it back in. I put it back in and gave it a test drive and I could be imagining things but I think it feels slightly better.

The fluid looks like it could be on the high side, but not enough to overflow or anything.

I couldn't get a good look into the slave hole, but I think I can get ahold of a borescope.

 

[machoheadgames]

Yes there's decent pressure needed to get it back in. I put it back in and gave it a test drive and I could be imagining things but I think it feels slightly better.

The fluid looks like it could be on the high side, but not enough to overflow or anything.

I couldn't get a good look into the slave hole, but I think I can get ahold of a borescope.

I’d probably take some fluid out and just keep an eye on it, hopeful that resetting the slave and taking some fluid out was enough to fix the issue.

 

[B1Toad]

My gut feeling is it may be time for a clutch. The good news is that it's easy to replace yourself, and cheap. Amazon has the original equipment LUK clutch kit with everything you need for $119.
That slave kit you have is an OEM Mopar, no longer available. It can be flushed and purged of all air very easily before re-installing. If you need a new kit I think the Oreilly's one is pretty good, I actually used that one for a while but changed it to a Mopar when I found one at Mopar Parts Giant but I think it was their last one.
One thing you might need is a new pivot pin retaining clip so if you're in a hurry and don't have time to wait for parts when it's tore down get one before you start.

 

[Squilt]

I fixed it. At least temporarily. I just followed this guide. Though I didn't see any bubbles coming out. Not even sure how air could have caused it. But the grab point is much closer to the floor now.

 

[Squilt]

Is it safe to say replacing the slave will prevent it from happening again?

 

[Squilt]

The issue came back the next day. I replaced the slave cylinder today and that for sure fixed it. By comparing the new and old one, I noticed that the old one required a lot more force to push in. I assume the clutch fork wasn't exerting enough force to return the rod to its original position, which explains the symptoms.

The bite point is now a bit closer to the floor than I'd like, but I can tell there's still some air I need to get out.

 

[B1Toad]

The issue came back the next day. I replaced the slave cylinder today and that for sure fixed it. By comparing the new and old one, I noticed that the old one required a lot more force to push in. I assume the clutch fork wasn't exerting enough force to return the rod to its original position, which explains the symptoms.

The bite point is now a bit closer to the floor than I'd like, but I can tell there's still some air I need to get out.

Did you replace slave and master as a kit? If so, those are pre bled, unless you let the slave piston pop out I found the easiest and fastest way to bleed is remove the slave and slowly push the piston in on the floor repeatedly till there's no more bubbles in the master, by keeping the slave down low and the line in an uphill orientation all the air will come out in the master. A few taps on the line helps to dislodge any air bubbles that are trying to stay behind.

BTW keep your eyes/face away from the master while doing this and lay the cover on top till you get things moving!

 

[machoheadgames]

Did you replace slave and master as a kit? If so, those are pre bled, unless you let the slave piston pop out I found the easiest and fastest way to bleed is remove the slave and slowly push the piston in on the floor repeatedly till there's no more bubbles in the master, by keeping the slave down low and the line in an uphill orientation all the air will come out in the master. A few taps on the line helps to dislodge any air bubbles that are trying to stay behind.

BTW keep your eyes/face away from the master while doing this and lay the cover on top till you get things moving!

All the pre bled units I've purchased have had some air in them initially, that works itself out after a little bit of driving.

 

[Squilt]

Did you replace slave and master as a kit? If so, those are pre bled, unless you let the slave piston pop out I found the easiest and fastest way to bleed is remove the slave and slowly push the piston in on the floor repeatedly till there's no more bubbles in the master, by keeping the slave down low and the line in an uphill orientation all the air will come out in the master. A few taps on the line helps to dislodge any air bubbles that are trying to stay behind.

BTW keep your eyes/face away from the master while doing this and lay the cover on top till you get things moving!

I replaced just the slave. That's exactly what I did.

 

[Squilt]

All the pre bled units I've purchased have had some air in them initially, that works itself out after a little bit of driving.

I'm noticing that as well. I'll drive on it for a bit and then try pushing the bubbles out again