Clutch Slipping?
Thread Starter
Instructor
Joined: Sep 2009
Posts: 127
Likes: 0
From: Richmond Virginia
Clutch Slipping?
I did some searches and came up empty....
Hears my problem and I hope to get some answers ... The 99FRC I just bought a few months back while shifting [I]fast[I] the clutch slipped twice in the 4th to fifth shift on me... I believe the fluid to be org ? the car only has 28000 miles and I think not driven hard I had seen somewhere about bleeding the system but not finding anything in the PDF manual ..I Googled it and came up with this
Evidently this is a common problem Corvettes (C4, C5, C6) caused by the clutch hydraulic fluid not being able to flow as fast as it should because of a restriction put in the tubing by the factory which is supposed to smooth out the clutch operation by causing some slippage, delaying the full engagement of the clutch. When you try and do quick (banging) multiple shifts in succession, the fluid can't return fast enough and the pedal falls to the floor. Normally in a low-speed autocross, we launch in 1st and leave it in 2nd, so we have not seen this before. In drag racing and long autocross (time-trial) courses, like the Colorado State Patrol track, this is when it appears.
I was blaming myself for miss-shifts and Becky was freaking out over the pedal, losing a lot of her concentration. If you slow the shifts down then you will not see the problem, but when you are fighting for 10th's of a second, you will not tend to restrain your shifting.
Some folks on the Corvette and Z06 forums have removed the clutch pedal spring (about a 30 sec job) which normally helps to push the pedal IN, therefore allowing the pedal to return.
Most have success by simply keeping their brake fluid clean by replacing it often. This is easy to do as the clutch hyraulics are self bleeding, and only takes a few minutes. Suck out the reservoir, add new Dot 3 or non-synthetic Dot 4 (like Motul 600) in your C5. The C6's use Dot 4 (GM part# 88958860 (US) 889012440) exclusively. Pump the clutch pedal 20-50 times, suck it out again, add more, pump pedal, and continue to repeat until the fluid is clean and clear. You may need up to 9 passes. Don't get the fluid on any of your painted parts. Here's the kit (Courtesy of Ranger on the Z06 Forum - Keep in a one-gallon Zip-lock bag) you need :
Is this whats happening to my FRC? and if not how do you adjust? /bleed... I also read something about the pressure plate being able to to be adjusted? without dropping exhaust is there anyway to inspect the clutch for dammage?
Hears my problem and I hope to get some answers ... The 99FRC I just bought a few months back while shifting [I]fast[I] the clutch slipped twice in the 4th to fifth shift on me... I believe the fluid to be org ? the car only has 28000 miles and I think not driven hard I had seen somewhere about bleeding the system but not finding anything in the PDF manual ..I Googled it and came up with this
Evidently this is a common problem Corvettes (C4, C5, C6) caused by the clutch hydraulic fluid not being able to flow as fast as it should because of a restriction put in the tubing by the factory which is supposed to smooth out the clutch operation by causing some slippage, delaying the full engagement of the clutch. When you try and do quick (banging) multiple shifts in succession, the fluid can't return fast enough and the pedal falls to the floor. Normally in a low-speed autocross, we launch in 1st and leave it in 2nd, so we have not seen this before. In drag racing and long autocross (time-trial) courses, like the Colorado State Patrol track, this is when it appears.
I was blaming myself for miss-shifts and Becky was freaking out over the pedal, losing a lot of her concentration. If you slow the shifts down then you will not see the problem, but when you are fighting for 10th's of a second, you will not tend to restrain your shifting.
Some folks on the Corvette and Z06 forums have removed the clutch pedal spring (about a 30 sec job) which normally helps to push the pedal IN, therefore allowing the pedal to return.
Most have success by simply keeping their brake fluid clean by replacing it often. This is easy to do as the clutch hyraulics are self bleeding, and only takes a few minutes. Suck out the reservoir, add new Dot 3 or non-synthetic Dot 4 (like Motul 600) in your C5. The C6's use Dot 4 (GM part# 88958860 (US) 889012440) exclusively. Pump the clutch pedal 20-50 times, suck it out again, add more, pump pedal, and continue to repeat until the fluid is clean and clear. You may need up to 9 passes. Don't get the fluid on any of your painted parts. Here's the kit (Courtesy of Ranger on the Z06 Forum - Keep in a one-gallon Zip-lock bag) you need :
Is this whats happening to my FRC? and if not how do you adjust? /bleed... I also read something about the pressure plate being able to to be adjusted? without dropping exhaust is there anyway to inspect the clutch for dammage?
Thread Starter
Instructor
Joined: Sep 2009
Posts: 127
Likes: 0
From: Richmond Virginia
I did some searches and came up empty....
Hears my problem and I hope to get some answers ... The 99FRC I just bought a few months back while shifting [I]fast[I] the clutch slipped twice in the 4th to fifth shift on me... I believe the fluid to be org ? the car only has 28000 miles and I think not driven hard I had seen somewhere about bleeding the system but not finding anything in the PDF manual ..I Googled it and came up with this
Evidently this is a common problem Corvettes (C4, C5, C6) caused by the clutch hydraulic fluid not being able to flow as fast as it should because of a restriction put in the tubing by the factory which is supposed to smooth out the clutch operation by causing some slippage, delaying the full engagement of the clutch. When you try and do quick (banging) multiple shifts in succession, the fluid can't return fast enough and the pedal falls to the floor. Normally in a low-speed autocross, we launch in 1st and leave it in 2nd, so we have not seen this before. In drag racing and long autocross (time-trial) courses, like the Colorado State Patrol track, this is when it appears.
I was blaming myself for miss-shifts and Becky was freaking out over the pedal, losing a lot of her concentration. If you slow the shifts down then you will not see the problem, but when you are fighting for 10th's of a second, you will not tend to restrain your shifting.
Some folks on the Corvette and Z06 forums have removed the clutch pedal spring (about a 30 sec job) which normally helps to push the pedal IN, therefore allowing the pedal to return.
Most have success by simply keeping their brake fluid clean by replacing it often. This is easy to do as the clutch hyraulics are self bleeding, and only takes a few minutes. Suck out the reservoir, add new Dot 3 or non-synthetic Dot 4 (like Motul 600) in your C5. The C6's use Dot 4 (GM part# 88958860 (US) 889012440) exclusively. Pump the clutch pedal 20-50 times, suck it out again, add more, pump pedal, and continue to repeat until the fluid is clean and clear. You may need up to 9 passes. Don't get the fluid on any of your painted parts. Here's the kit (Courtesy of Ranger on the Z06 Forum - Keep in a one-gallon Zip-lock bag) you need :
Is this whats happening to my FRC? and if not how do you adjust? /bleed... I also read something about the pressure plate being able to to be adjusted? without dropping exhaust is there anyway to inspect the clutch for dammage?
Hears my problem and I hope to get some answers ... The 99FRC I just bought a few months back while shifting [I]fast[I] the clutch slipped twice in the 4th to fifth shift on me... I believe the fluid to be org ? the car only has 28000 miles and I think not driven hard I had seen somewhere about bleeding the system but not finding anything in the PDF manual ..I Googled it and came up with this
Evidently this is a common problem Corvettes (C4, C5, C6) caused by the clutch hydraulic fluid not being able to flow as fast as it should because of a restriction put in the tubing by the factory which is supposed to smooth out the clutch operation by causing some slippage, delaying the full engagement of the clutch. When you try and do quick (banging) multiple shifts in succession, the fluid can't return fast enough and the pedal falls to the floor. Normally in a low-speed autocross, we launch in 1st and leave it in 2nd, so we have not seen this before. In drag racing and long autocross (time-trial) courses, like the Colorado State Patrol track, this is when it appears.
I was blaming myself for miss-shifts and Becky was freaking out over the pedal, losing a lot of her concentration. If you slow the shifts down then you will not see the problem, but when you are fighting for 10th's of a second, you will not tend to restrain your shifting.
Some folks on the Corvette and Z06 forums have removed the clutch pedal spring (about a 30 sec job) which normally helps to push the pedal IN, therefore allowing the pedal to return.
Most have success by simply keeping their brake fluid clean by replacing it often. This is easy to do as the clutch hyraulics are self bleeding, and only takes a few minutes. Suck out the reservoir, add new Dot 3 or non-synthetic Dot 4 (like Motul 600) in your C5. The C6's use Dot 4 (GM part# 88958860 (US) 889012440) exclusively. Pump the clutch pedal 20-50 times, suck it out again, add more, pump pedal, and continue to repeat until the fluid is clean and clear. You may need up to 9 passes. Don't get the fluid on any of your painted parts. Here's the kit (Courtesy of Ranger on the Z06 Forum - Keep in a one-gallon Zip-lock bag) you need :
Is this whats happening to my FRC? and if not how do you adjust? /bleed... I also read something about the pressure plate being able to to be adjusted? without dropping exhaust is there anyway to inspect the clutch for dammage?
Safety Car
Joined: Dec 2004
Posts: 3,526
Likes: 18
From: Santa Fe TX
Some people report the fluid changes improve shifting. Some for good, some for a while. Some people drill out that line, but I think this can only be done during a clutch change.
Eventually with any kind of racing, the stock clutch or hydraulics will give out.
Eventually with any kind of racing, the stock clutch or hydraulics will give out.
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
The fluid thing is more about the pedal sticking to the floor, if your clutch is slipping, it's most likely time for a new clutch.
A clutch can last 100K miles or 100 miles-depends on the driver like this dufus.
http://www.break.com/index/corvette-...ys-clutch.html
A clutch can last 100K miles or 100 miles-depends on the driver like this dufus.
http://www.break.com/index/corvette-...ys-clutch.html
Last edited by dougbfresh; Feb 22, 2010 at 03:07 PM.
Burning Brakes
Joined: Mar 2002
Posts: 844
Likes: 11
From: Il
The fluid thing is more about the pedal sticking to the floor, if your clutch is slipping, it's most likely time for a new clutch.
A clutch can last 100K miles or 100 miles-depends on the driver like this dufus.
http://www.break.com/index/corvette-...ys-clutch.html
A clutch can last 100K miles or 100 miles-depends on the driver like this dufus.
http://www.break.com/index/corvette-...ys-clutch.html
WTF?
