Clutch Fluid
Thread Starter
Pro
Joined: Jun 2014
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Clutch Fluid
I had my fourth and final free oil change today, and told the dealer to change the clutch fluid "if needed", since the car is now exactly 2 years old. The Corvette tech said it didn't need changing, in spite of what the owners' manual says. I didn't question his judgement; after all, the fluid change would have been chargeable to me. At least it's a matter of record that I inquired about it.
Burning Brakes
Joined: Feb 2011
Posts: 833
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From: Goodyear AZ
I had my fourth and final free oil change today, and told the dealer to change the clutch fluid "if needed", since the car is now exactly 2 years old. The Corvette tech said it didn't need changing, in spite of what the owners' manual says. I didn't question his judgement; after all, the fluid change would have been chargeable to me. At least it's a matter of record that I inquired about it.
Le Mans Master
Joined: Sep 2003
Posts: 8,847
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From: Longview Texas
Its a very easy change and if you have ever looked at that fluid, it gets nasty quick. About every six months (4k miles) I use a syringe and pull the fluid out of the reservoir and add new Dot 4 brake fluid. Takes less than 5 minutes, less than $5. and I know the fluid is staying nice and clean. If your brake fluid in the reservoir was that dark and dirty looking, they would tell you it needed changed, that's why I just do that stuff myself as I know its always good to go.
Moderator
Joined: Feb 2006
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From: DFW Area TX
And you can accomplish the essentially the same thing using the "Ranger Method". As described above, suction the fluid out of the reservoir, refill, close reservoir, pump the clutch several times. Repeat until the fluid in the reservoir is clean. For exact procedure, search for "Ranger method".
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
And you can accomplish the essentially the same thing using the "Ranger Method". As described above, suction the fluid out of the reservoir, refill, close reservoir, pump the clutch several times. Repeat until the fluid in the reservoir is clean. For exact procedure, search for "Ranger method".
Melting Slicks
Joined: Jan 2004
Posts: 2,299
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From: Fort Worth TX
St. Jude Donor '14-'15
And you can accomplish the essentially the same thing using the "Ranger Method". As described above, suction the fluid out of the reservoir, refill, close reservoir, pump the clutch several times. Repeat until the fluid in the reservoir is clean. For exact procedure, search for "Ranger method".
Last edited by hisvett; Mar 22, 2016 at 10:25 PM.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 35,010
Likes: 12,393
From: NE South Carolina
And you can accomplish the essentially the same thing using the "Ranger Method". As described above, suction the fluid out of the reservoir, refill, close reservoir, pump the clutch several times. Repeat until the fluid in the reservoir is clean. For exact procedure, search for "Ranger method".
The Service Manual calls for removing exhaust pipes and the catalytic converter to access the bleed screw on the slave cylinder. Not easy or cheap. I have used the Ranger Method on my C6 and twice in my C7. Easy to do. See pic below of fluid before and after 6 changes of 30 pumps each. Good exercise for your left foot! 
Regardless of what the dealer told the OP, the 2014 Owner's Manual says change every 2 years and the 2016 every 3 years (changed for some reason.)
No doubt the fluid looks dark, which is not necessarily a reason to change. But I figure if using the Ranger method about every year I'm getting close to a recommenced (~$150+) dealer change every few years.
There is no easy way to check to see "if it needs to be changed!" Could measure water content, which if not changed that can cause corrosion in the cylinders. Dot 3 and 4 fluids pick up water.
Brakes are the same issue requiring a change every 3 years. In that case you need to bleed at each wheel. That will cost ~$150 at dealer. I will have 3 years in October, waiting for the dealer offer a $50 off special as they sell BMW's and Mercedes that also require the brake fluid change.
Clutch Fluid After 1st and 6th Change Using a Simple Replace and Pump Proceedure
Last edited by JerryU; Mar 23, 2016 at 08:50 AM.
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Thread Starter
Pro
Joined: Jun 2014
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Its a very easy change and if you have ever looked at that fluid, it gets nasty quick. About every six months (4k miles) I use a syringe and pull the fluid out of the reservoir and add new Dot 4 brake fluid. Takes less than 5 minutes, less than $5. and I know the fluid is staying nice and clean. If your brake fluid in the reservoir was that dark and dirty looking, they would tell you it needed changed, that's why I just do that stuff myself as I know its always good to go.
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,102
From: Fulshear, TX
I had my fourth and final free oil change today, and told the dealer to change the clutch fluid "if needed", since the car is now exactly 2 years old. The Corvette tech said it didn't need changing, in spite of what the owners' manual says. I didn't question his judgement; after all, the fluid change would have been chargeable to me. At least it's a matter of record that I inquired about it.
Melting Slicks
Joined: Jan 2000
Posts: 3,326
Likes: 523
From: home
Its a very easy change and if you have ever looked at that fluid, it gets nasty quick. About every six months (4k miles) I use a syringe and pull the fluid out of the reservoir and add new Dot 4 brake fluid. Takes less than 5 minutes, less than $5. and I know the fluid is staying nice and clean. If your brake fluid in the reservoir was that dark and dirty looking, they would tell you it needed changed, that's why I just do that stuff myself as I know its always good to go.
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,102
From: Fulshear, TX
The Ranger Method seems great if you're concerned more about the color of the fluid than the actual quality of the fluid in the slave. For $80 every other year, I'm just going to keep having my dealership do it per the maintenance schedule.
Thread Starter
Pro
Joined: Jun 2014
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I too just had my car in for the 4th and final free oil change. I had the dealership perform the clutch fluid flush procedure and it made a noticeable difference in clutch operation. Smoother and more consistent; the service was definitely due and I now see why Chevy says to get it done every 2 years. My car has 22k miles on it.
Race Director
Joined: Sep 2001
Posts: 16,507
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From: Southern Indiana
Using the ranger method, is it very obvious the fluid circulates. When you change out the master, pump (or drive for a bit) and change it out again several times, you are replacing the fluid that goes into the slave. Yes, it will not be 100% as a full flush/fill would be, but you can get most of the way there. For instance, assuming that the master cylinder holds 25% of the fluid, you have removed 82.2% of the old fluid after 6 iterations.
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,102
From: Fulshear, TX
Using the ranger method, is it very obvious the fluid circulates. When you change out the master, pump (or drive for a bit) and change it out again several times, you are replacing the fluid that goes into the slave. Yes, it will not be 100% as a full flush/fill would be, but you can get most of the way there. For instance, assuming that the master cylinder holds 25% of the fluid, you have removed 82.2% of the old fluid after 6 iterations.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 35,010
Likes: 12,393
From: NE South Carolina
I don't think this does anything in regards to bleeding the clutch fluid. The reservoir fluid is changed but what about the fluid in the slave? The line from the master to the slave? The clutch master cylinder itself? Using this procedure, I can bleed the brakes by changing the fluid in the master cylinder reservoir and pump the brake pedal? They're both sealed hydraulic systems.I don't think so...........
Using the ranger method, is it very obvious the fluid circulates. When you change out the master, pump (or drive for a bit) and change it out again several times, you are replacing the fluid that goes into the slave. Yes, it will not be 100% as a full flush/fill would be, but you can get most of the way there. For instance, assuming that the master cylinder holds 25% of the fluid, you have removed 82.2% of the old fluid after 6 iterations.
After emptying the reservoir I fill with new fluid (Prestone Dot 4 is a quality product and 12 oz at Walmart is under $4, don't buy a bigger container as all DOT 3 & 4 picks up water out of the air when you open the container! Toss when finished)
I pump the clutch peddle 30 times at each empty/refill, as recommended.
The fluid gets cleaner as you pump. Then I did it 8 times and it got cleaner with each cycle. At 8 it looked like fluid out of the container, clear.
I used that method for 6 years with my C6 and never had a problem. This is a PDF of my 1st flush with pics of the fluid after each of the 8 cycles: http://netwelding.com/Clutch_Fluid.pdf
Do as you wish and pay the dealer IF you're sure they removed the exhaust pipe and catalytic converter and blead from the slave cylinder! Your car your choice!
If you read the ranger documentation and watch his video AND you drag race, do it after every race. If fact after seeing his video and the particles accumulated when you abuse the clutch (as in drag racing) think I might learn to remove the exhaust and get a buddy to help bleed after each race!
Last edited by JerryU; Mar 24, 2016 at 12:33 PM.
Moderator
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From: DFW Area TX
Not really; the "Ranger Method" deals with one (Clutch) slave piston, your brakes (Z51 anyway) has 6 "sets" of pistons between all 4 wheels and they are a lot farther apart. You would wear out your brake peddle along with using up an awful lot of brake fluid trying to dilute what is in the system. Having said that, I will change out the master reservoir every time I change my oil.....just to keep the system a little fresher between performing a full system flush before hitting the track.
Burning Brakes
Joined: Apr 2006
Posts: 1,174
Likes: 53
From: Largo Florida
I bought a liter of Pentosin Super DOT4. I keep it sealed tight in a dry place, but I will not keep it over a year once opened. Rather than waste it, I do the ranger method every month to keep the fluid fresh. Obvious overkill, but why not since it comes in such a large quantity. I do drive the car hard in Florida heat as well as stop and go traffic.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 35,010
Likes: 12,393
From: NE South Carolina
Using the ranger method, is it very obvious the fluid circulates. When you change out the master, pump (or drive for a bit) and change it out again several times, you are replacing the fluid that goes into the slave. Yes, it will not be 100% as a full flush/fill would be, but you can get most of the way there. For instance, assuming that the master cylinder holds 25% of the fluid, you have removed 82.2% of the old fluid after 6 iterations.
Your 82.2% reminded me of the first time I appreciated Differential Equations! Our college worked closely with a local hospital and the Prof was terrific, (He was retired from Bell Labs, had invented the rotary dial switching system said he learned French so he could teach himself “The Calculus!” Apparently the best text was in a French!) In the text book he wrote there was a differential equation problem of replacing blood in a blue baby and assuming proper mixing, how much blood had to be added to get to ~95 new? He had practical examples throughout the text. He commented that most college text books are written by professors to impress their peers and he wrote his for students!This is a pic of the C7 slave cylinder from the Service Manual, pretty small. My “guess” is the reservoir may hold 50% not 25% of the fluid so that 82.2% may be more like 90+%! My fluid looked like that or better after 8 empty/fill cycles! For the 2nd flush I stopped at 6 cycles!
C7 Clutch Slave Actuator.
Last edited by JerryU; Mar 24, 2016 at 04:08 PM.
Burning Brakes
Joined: Aug 2015
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From: LaGrange KY