What's going on with my clutch? -PLEASE HELP!!!!

[LS2Goat]

I've got about 10k miles on my lq4 swap in my 93 k1500. I haven't had a single problem to date with the engine, but my clutch system has been a nightmare. I am running a stock 350 clutch kit behind the 6.0, and mated to an nv4500 trans with the external slave bell housing. It always seemed to have a heavy clutch, but I didn't think much of it. Also, shortly after I did the swap, my throwout bearing started squeaking, it never got worse, or better, so I left it.

My problem started when the clutch fork bound up somehow and I popped the master cylinder. After this happened, I replaced the master cylinder, clutch kit, clutch line, clutch fork, and pivot ball. I put a new slave cylinder in when I did the swap so I let that be. All was well for about 30 miles but then my slave cylinder developed a crack near the bleed screw. I have about 500 miles on it since I replaced the faulty slave cylinder and all seems well now, but for how long? Every component in the clutch system is new, so what could be causing the heavy pedal? I'm thinking excessive pressure is what is causing the failures, but from what?

Also, my new throwout bearing is also doing the same squealing the old one did. Mind you the first bearing was a cheapy, but the new one is a Timken. Should the bearing always be riding on the pressure plate fingers, even with the clutch disengaged? There is no adjustment on a hydro clutch so I'm at a loss what to do there...

Any help would be greatly appreciated!! Thanks!

 

[Ruger_556]

I've got about 10k miles on my lq4 swap in my 93 k1500. I haven't had a single problem to date with the engine, but my clutch system has been a nightmare. I am running a stock 350 clutch kit behind the 6.0, and mated to an nv4500 trans with the external slave bell housing. It always seemed to have a heavy clutch, but I didn't think much of it. Also, shortly after I did the swap, my throwout bearing started squeaking, it never got worse, or better, so I left it.

My problem started when the clutch fork bound up somehow and I popped the master cylinder. After this happened, I replaced the master cylinder, clutch kit, clutch line, clutch fork, and pivot ball. I put a new slave cylinder in when I did the swap so I let that be. All was well for about 30 miles but then my slave cylinder developed a crack near the bleed screw. I have about 500 miles on it since I replaced the faulty slave cylinder and all seems well now, but for how long? Every component in the clutch system is new, so what could be causing the heavy pedal? I'm thinking excessive pressure is what is causing the failures, but from what?

Also, my new throwout bearing is also doing the same squealing the old one did. Mind you the first bearing was a cheapy, but the new one is a Timken. Should the bearing always be riding on the pressure plate fingers, even with the clutch disengaged? There is no adjustment on a hydro clutch so I'm at a loss what to do there...

Any help would be greatly appreciated!! Thanks!

Stiff clutch springs maybe Is it an "upgrade" or a standard clutch? I don't really work on light duty stuff but I don't think the throwout bearing is supposed to be constantly engaged...

 

[sewlow]

I don't think the throwout bearing is supposed to be constantly engaged...

Clutch pedal should have some free-play at the top. 1/2"? This allows the throw-out bearing to completely disengaged.
I'm more experienced with mechanical clutches. Getting some kind of adjustment out of a hydraulic style has me baffled too.
So far, you've done about everything that I would have suggested.
Next thing I would check would be the clutch itself, as in, is that 350 clutch the proper one to be between a 6.0 & a NV4500?
Just throwing ideas out there. Curious to know as to how this could be cured.

 

[Ruger_556]

Clutch pedal should have some free-play at the top. 1/2"? This allows the throw-out bearing to completely disengaged.
I'm more experienced with mechanical clutches. Getting some kind of adjustment out of a hydraulic style has me baffled too.
So far, you've done about everything that I would have suggested.
Next thing I would check would be the clutch itself, as in, is that 350 clutch the proper one to be between a 6.0 & a NV4500?
Just throwing ideas out there. Curious to know as to how this could be cured.

1/2" is the magical number for truck clutches but I've never worked on a hydraulic clutch

 

[great white]

Have a good hard look at your belhousing to block area for loose bolts of anything that may have been caught on assembly and causing a slight misalignment.

That's just quick off the top of my head....

 

[LS2Goat]

Thanks for the ideas guys, but it's a stock clutch kit, and there aren't any alignment issues.

I tried running. 6.0 clutch kit behind it when I first did the swap but it had clearance issues with the bell housing.

I just finished replacing a broken exhaust bolt on my trailblazer as yesterday and when I moved my pickup out of the way... popped the master cylinder AGAIN! Argh!!

I think my next step is to buy a new style bell housing and go to an internal slave. I'm tired of throwing money at this clutch system though haha.

 

[sewlow]

When the clutch master goes, what exactly happens? Does it actually blow up & spew fluid everywhere, or does it just not return the pedal completely back to the top? Just wondering for future reference.

 

[LS2Goat]

Both of mine have cracked in the front and shot brake fluid all over the fender well.