Squeaking clutch after changing fluid in clutch reservoir!
08-25-2009, 01:20 PM
#1
Burning Brakes
Thread Starter
Squeaking clutch after changing fluid in clutch reservoir!
I just did the Ranger method of changing the clutch fluid (http://forums.corvetteforum.com/c5-z...-issues-2.html) and after a few pumps of the clutch my clutch master cylinder is now squawking! I am 
!
I used Prestone Dot-4, which is supposed to be compatible with Dot-3. The owners manual says that you can use GM 12345347 or Dot-3 so I didn't think much about using Dot-4.
I immediately went down to my local Chevy dealer and bought some GM 12345347 and tried replacing the Prestone using the Ranger method and the squeak is still there! So I may have ruined my clutch master cylinder!
Do yourself a favor and DON'T use brake fluid! Use GM 12345347. It supposedly has some seal lubricant in it.
Others have had this problem so be aware! Hopefully the squeaky will go away over time.
By the way, my shop manual says that you don't have to change the fluid if it looks dark. This is normal and is caused by the carbon in the seals and does not effect clutch performance. I wish I had followed what the manual said
.
!I used Prestone Dot-4, which is supposed to be compatible with Dot-3. The owners manual says that you can use GM 12345347 or Dot-3 so I didn't think much about using Dot-4.
I immediately went down to my local Chevy dealer and bought some GM 12345347 and tried replacing the Prestone using the Ranger method and the squeak is still there! So I may have ruined my clutch master cylinder!
Do yourself a favor and DON'T use brake fluid! Use GM 12345347. It supposedly has some seal lubricant in it.
Others have had this problem so be aware! Hopefully the squeaky will go away over time.
By the way, my shop manual says that you don't have to change the fluid if it looks dark. This is normal and is caused by the carbon in the seals and does not effect clutch performance. I wish I had followed what the manual said
.
08-25-2009, 01:49 PM
#2
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I just did the Ranger method of changing the clutch fluid (http://forums.corvetteforum.com/c5-z...-issues-2.html) and after a few pumps of the clutch my clutch master cylinder is now squawking! I am !
I used Prestone Dot-4, which is supposed to be compatible with Dot-3. The owners manual says that you can use GM 12345347 or Dot-3 so I didn't think much about using Dot-4.
I immediately went down to my local Chevy dealer and bought some GM 12345347 and tried replacing the Prestone using the Ranger method and the squeak is still there! So I may have ruined my clutch master cylinder!
Do yourself a favor and DON'T use brake fluid! Use GM 12345347. It supposedly has some seal lubricant in it.
Others have had this problem so be aware! Hopefully the squeaky will go away over time.
By the way, my shop manual says that you don't have to change the fluid if it looks dark. This is normal and is caused by the carbon in the seals and does not effect clutch performance. I wish I had followed what the manual said.
!I used Prestone Dot-4, which is supposed to be compatible with Dot-3. The owners manual says that you can use GM 12345347 or Dot-3 so I didn't think much about using Dot-4.
I immediately went down to my local Chevy dealer and bought some GM 12345347 and tried replacing the Prestone using the Ranger method and the squeak is still there! So I may have ruined my clutch master cylinder!
Do yourself a favor and DON'T use brake fluid! Use GM 12345347. It supposedly has some seal lubricant in it.
Others have had this problem so be aware! Hopefully the squeaky will go away over time.
By the way, my shop manual says that you don't have to change the fluid if it looks dark. This is normal and is caused by the carbon in the seals and does not effect clutch performance. I wish I had followed what the manual said
.GM recommends DOT4 fluid for all Corvette clutches. That change was made via a tech bulletin in 2007. Your dealer isn't up to date.
It's proven that clutch dust is turning the fluid black. Watch the video.
Ranger
Last edited by Ranger; 08-25-2009 at 01:51 PM.
08-25-2009, 02:00 PM
#3
Burning Brakes
Thread Starter
Good to hear the squeak will go away
Thousands of Corvette owners have kept their clutches operating perfectly using Prestone DOT4 fluid and the protocol I recommend. The squeak you note will disappear with some pedal pumps and driving.
GM recommends DOT4 fluid for all Corvette clutches. That change was made via a tech bulletin in 2007. Your dealer isn't up to date.
It's proven that clutch dust is turning the fluid black. Watch the video.
Ranger
GM recommends DOT4 fluid for all Corvette clutches. That change was made via a tech bulletin in 2007. Your dealer isn't up to date.
It's proven that clutch dust is turning the fluid black. Watch the video.
Ranger
Thanks for the info. Hopefully it will go away soon because it is very annoying
. As a FYI, the GM product specifically states that it has lubricants to help eliminate clutch squeaking. Wonder why they put that on the label? It is also quite expensive at $16.50!
08-25-2009, 02:09 PM
#5
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I've used Prestone DOT4 is two C5Zs and one C6Z without issue. Zero squeaks. I sometimes have used GM Super DOT4 too. Performs no differently than Prestone DOT4.
I've seen squeaks in a few C5 clutches when first experiencing DOT4. I always suggest repeating the flushes until the fluid remains clean. The squeaks have always disappeared. Suspect yours will to with repeated flushes.
A master cylinder will last indefinitely with clean fluid. With clutch-dust laden corrupt fluid it's service life is severely truncated. All depends on how aggressively the car is driven.
Good luck. Let us know what you find about the squeak.
Ranger
Last edited by Ranger; 09-07-2009 at 02:32 PM.
09-07-2009, 02:41 PM
#8
Race Director
Ive done the ranger method several times using Prestone Dot 4 and mine is still quiet. 
curious, how can a clutch master cylinder make noise if its just a cup holding fluid?
curious, how can a clutch master cylinder make noise if its just a cup holding fluid?
09-07-2009, 06:54 PM
#9
Burning Brakes
Thread Starter
Still squeaking
Not it hasn't gone away yet. I have put about 300 miles on the ODO since I changed the fluid. I think that it sounds a little better though. Hopefully a few hundred more miles might clear it up.
09-07-2009, 06:57 PM
#10
Burning Brakes
Thread Starter
09-08-2009, 06:13 AM
#14
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Prestone DOT4 has been run in many C5s. Should work in yours too.
Anyone going with GM brand needs the "Super DOT4 Brake and Clutch fluid PN 88958860." It's 5X the price of Prestone DOT4 and performs about the same.
Ranger
09-08-2009, 12:19 PM
#15
Le Mans Master
Until I need to flush the whole system, I am sticking with the GM DOT 3 fluid, which is supposed to have additional friction modifiers.
You may have trouble getting it since most dealers are now just stocking the new DOT 4 part number for the C6s.
It is one of those parts that if the dealer does not stock it, you will have to order a case from GM. I searched the dealers in my area and finally found some.
You may have trouble getting it since most dealers are now just stocking the new DOT 4 part number for the C6s.
It is one of those parts that if the dealer does not stock it, you will have to order a case from GM. I searched the dealers in my area and finally found some.
09-08-2009, 12:23 PM
#16
Le Mans Master
You are confusing the master cylinder with the reservoir. The master cylinder is attached to the clutch pedal and is what pumps fluid to the slave cylinder.
09-08-2009, 01:34 PM
#17
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Until I need to flush the whole system, I am sticking with the GM DOT 3 fluid, which is supposed to have additional friction modifiers.
You may have trouble getting it since most dealers are now just stocking the new DOT 4 part number for the C6s.
It is one of those parts that if the dealer does not stock it, you will have to order a case from GM. I searched the dealers in my area and finally found some.
You may have trouble getting it since most dealers are now just stocking the new DOT 4 part number for the C6s.
It is one of those parts that if the dealer does not stock it, you will have to order a case from GM. I searched the dealers in my area and finally found some.
Others should be aware of two points.
In 2007 GM Power Train revised the spec for fluid for all Corvettes with a hydraulic clutch. It was changed to DOT4 brake fluid, vice the previously specified DOT3. That change offers a higher dry and wet boiling point for the clutch fluid.
Both GM-brand Super DOT4 and Prestone DOT4 are compatible with GM DOT3, that was OEM in C5 Z06s. So the three fluids can be mixed without issue. There is no need to change all the fluid at once.
The more times you swap the contents of the clutch reservoir using DOT4, the cleaner the fluid will be, eliminating accumulated clutch dust, and the closer the boiling point will be to the new Corvette spec.
Ranger
09-08-2009, 02:18 PM
#18
Race Director
09-08-2009, 02:38 PM
#19
Drifting
I have been using Prestone DOT4 and the Ranger method for clutch fluid swaps ever since I picked up my Z earlier this year. No squeaks, and I swear the shifting has improved (could be in my head though). Doesn't DOT4 have a higher boiling point too? Regardless, as Ranger mentions, it is recommended per a GM service bulletin and much cheaper than GM's own stuff. Very cheap at Walmart and will save you lots of $$$ in the future if you do this routine maintenance! 
