C5 Z Clutch Issue
Thread Starter
Racer
Joined: Jun 2013
Posts: 284
Likes: 22
From: Concord NH
C5 Z Clutch Issue
Just completed a major upgrade to my '03 Z. New motor (383 stroker with ARH headers, Trick Flow heads, roller rockers, on and on...). The clutch was also rebuilt with a Kevlar clutch plate.
I'm just over 800 miles on the break in and just starting to let it run to higher rpm's... And then the clutch sticks and I have to pull the car out of gear. It only happens when the rpm's have gone above 5,500 (closer to 6,000). Otherwise, it shifts perfectly normally. When the problem occurs, it feels like the pedal pretty much goes to the floor. After taking it out of gear, and returning to lower rpm's, the clutch behaves normally again.
The clutch has a remote bleeder. We bleed it once and thought that it was just some old fluid. The issue returned yesterday.
Since the clutch was rebuilt, I'm pretty sure that the slave is in good shape. However, I know that the Master was not replaced. Could it really be as simple as the Master?
The bell housing area is completely dry.
Any thoughts/ideas would be greatly appreciated!
Jeff
I'm just over 800 miles on the break in and just starting to let it run to higher rpm's... And then the clutch sticks and I have to pull the car out of gear. It only happens when the rpm's have gone above 5,500 (closer to 6,000). Otherwise, it shifts perfectly normally. When the problem occurs, it feels like the pedal pretty much goes to the floor. After taking it out of gear, and returning to lower rpm's, the clutch behaves normally again.
The clutch has a remote bleeder. We bleed it once and thought that it was just some old fluid. The issue returned yesterday.
Since the clutch was rebuilt, I'm pretty sure that the slave is in good shape. However, I know that the Master was not replaced. Could it really be as simple as the Master?
The bell housing area is completely dry.
Any thoughts/ideas would be greatly appreciated!
Jeff
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
You are leaving out a LOT of needed information or assuming we know what it is???
What all was replaced when the CLUTCh was rebuilt?????? Slave? Throwout Brg? Pilot Brg? Disk?? Pressure Plate?
If you didnt replace the master,, that would be the VERY FIRST next step!
Do you have a remote bleeder kit installed??? Is the clutch slave/master blead properly????
BC
What all was replaced when the CLUTCh was rebuilt?????? Slave? Throwout Brg? Pilot Brg? Disk?? Pressure Plate?
If you didnt replace the master,, that would be the VERY FIRST next step!
Do you have a remote bleeder kit installed??? Is the clutch slave/master blead properly????
BC
Last edited by Bill Curlee; Nov 7, 2015 at 08:21 PM.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
I would also suspect the master as well as need for bleeding again----As the fluid warms up with engine temps it becomes more sensitive to any air bubbles in the system--The clutch going to the floor makes me think you still have air in your system OR the master has an air leak--
This is all assuming the clutch installer put in the correct clutch and checked the install clearances properly--
This is all assuming the clutch installer put in the correct clutch and checked the install clearances properly--
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I would also suspect the master as well as need for bleeding again----As the fluid warms up with engine temps it becomes more sensitive to any air bubbles in the system--The clutch going to the floor makes me think you still have air in your system OR the master has an air leak--
This is all assuming the clutch installer put in the correct clutch and checked the install clearances properly--
This is all assuming the clutch installer put in the correct clutch and checked the install clearances properly--
Thread Starter
Racer
Joined: Jun 2013
Posts: 284
Likes: 22
From: Concord NH
Thank you so much!
I do have a remote bleeder on the slave so yesterday I used a vacuum pump to completely refresh the system with new fluid. The old stuff was a bit murky but I really didn't see any bubbles.
A test ride yielded the same results - no clutch at high rpms. What is causing this phenomena? I'm curious...
I should have searched the forums before I posted my question as I found this to be a common issue. So, my apologies for wasting anyone's time and my thanks to those who answered. In the future, I'll be sure to search before posting!
I agree - Master cylinder change is in order. No signs of fluid loss from any of the hydraulic components. So hopefully the slave is fine.
Thanks to all who replied. Hopefully the Master will solve the issue and this post will end right here.
Jeff
I do have a remote bleeder on the slave so yesterday I used a vacuum pump to completely refresh the system with new fluid. The old stuff was a bit murky but I really didn't see any bubbles.
A test ride yielded the same results - no clutch at high rpms. What is causing this phenomena? I'm curious...
I should have searched the forums before I posted my question as I found this to be a common issue. So, my apologies for wasting anyone's time and my thanks to those who answered. In the future, I'll be sure to search before posting!
I agree - Master cylinder change is in order. No signs of fluid loss from any of the hydraulic components. So hopefully the slave is fine.
Thanks to all who replied. Hopefully the Master will solve the issue and this post will end right here.
Jeff
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Jeff
The master cylinder has been known to cause this BUT,,,, Problems with the pressure plate can also contribute to this issue. The master cylinder is the least expensive and easiest to replace if you are still having issues.
They get contaminated with nasty dust which turns into black goop and that causes then to have all sorts of weird issues.
What pressure plate did you use?
The master cylinder has been known to cause this BUT,,,, Problems with the pressure plate can also contribute to this issue. The master cylinder is the least expensive and easiest to replace if you are still having issues.
They get contaminated with nasty dust which turns into black goop and that causes then to have all sorts of weird issues.
What pressure plate did you use?
Last edited by Bill Curlee; Nov 8, 2015 at 11:34 AM.
Thread Starter
Racer
Joined: Jun 2013
Posts: 284
Likes: 22
From: Concord NH
Bill,
I'm embarrassed to admit that I don't know if the original pressure plate was reinstalled with the Kevlar clutch plate or the new plate came with a new pressure plate... What's the normal convention?
I'm embarrassed to admit that I don't know if the original pressure plate was reinstalled with the Kevlar clutch plate or the new plate came with a new pressure plate... What's the normal convention?
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Thread Starter
Racer
Joined: Jun 2013
Posts: 284
Likes: 22
From: Concord NH
It was built by Corvettes of Westchester. I'll be talking to them tomorrow...
There's now a "tick" sound from the front of the engine at idle... Don't remember that from before yesterday. I've only got about 850 miles on the build so far...
There's now a "tick" sound from the front of the engine at idle... Don't remember that from before yesterday. I've only got about 850 miles on the build so far...
Last edited by jdm767; Nov 8, 2015 at 12:12 PM.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If Chuck did the work, I would say that it was done correctly.. I would start with a new Master and a good flush and bleed... That should take care of it.
I can not attend the event due to commentments.
Bill
I can not attend the event due to commentments.
Bill