Issues With Clutch Engagement

I tried to get some answers to my question through a similar post but no one has chipped in,

I've currently got the late model CJ/YJ master and slave combo which I believe is 13/16 and 7/8 respectively brought from Rockauto. The pedal i believe is from the later CJ/YJ and uses basic factory mounting points and is top hanging. I have an adjustable pushrod/entension on the slave and its mounted in the factory positioning on the Jeep T18 bellhousing.. Note all parts are new including the clutch and was installed either during my upgrade from the T150 or afterwards when the issues began. The issue I've been experiencing is that when I adjust the clutch lever at the bellhousing to the point of slight freeplay with the slave in the most compressed position, the clutch will works fine immediately after the setup but after a few uses of the clutch (say less than 6) the clutch starts to slip and the pushrod at the slave becomes either rock solid (no more freeplay) or has over extended and pushed the pushrod out of the slave. I have tried everything I can think of to rectify this and I'm not getting anywhere. This should be a very simple thing to setup but its absolutely wrecking my head and has my Jeep parked up because of it.

I have no idea why this is happening as it's the exact same setup I had with the T150 that worked perfectly for 5 years or so, nothing was modified/changed etc on setup except for the gearbox which basically uses the same bellhousing.

Can anyone think of what might be happening/causing this. I'm willing to try a different set up if a known one works (I'll need Rockauto part numbers as purchasing outside of the US).

Also if someone can tell me the correct master cylinder pushrod height on the pedal (ie from the pivot) it would be appreciated as I'd like to double check everything.

 

You do not mention the master cylinder. To me it sounds as though the clutch petal is not completely releasing the master cylinder. In other words, the master cylinder is not returning to it most relaxed position. If this is occurring, the slave cylinder can slowly build up pressure and do what you are describing.

 

Maybe the throw-out bearing is hanging up and the spring is not pulling it all the way back allowing the slave to return all the way back.

 

Do u have a return spring on the clutch fork?

 

Yes I have a spring on the clutch fork

 

How about a return on the pedal?

 

No return on the pedal, never seen one on a pedal before, is this normal or just a suggestion?

 

I may be mistaken, but here is a factory YJ setup. I believe the & pedals are basically the same.
OEM JEEP YJ WRANGLER BRAKE & CLUTCH PEDAL ASSEMBLY 1992-1995 4 & 6 CYL | eBay

 

First off you should adjust free play in the relaxed position and not the compressed position as you mentioned............Hydraulic clutches can and for the most part be somewhat self-adjustable as wear accumulates from the friction material going away......the sealed hydraulic system well compensate for the wear.........a change in push rod length at the slave may help but it really just moves where the clutch will engage.........true free play in a hydraulic system is usually obtained by adjusting the clutch pedal travel at the pedal set.......

 

Thanks guys, I'll have a quick look at mine as it's been a while and look at what's going on. The problem I had with setting the adjustment at the relaxed point was that the pushrod would extend beyond the slave after a couple of pushes. That's why I reverted back to using the compressed point instead. One other thing I've noted since changing over to the new parts is the pedal feel is very light, almost too light. To me that would mean I've too much leverage or wrong cylinder ratios. I still have all the old bits so can easily change back as it seems something else is the problem.

 

Could anyone post a diagram of the throw out bearing spring and how it connects to the bearing