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….I'm thinking you would have to do the ranger method several times to see positive results.
First: the Ranger method says do 6 or 7 times with 30 clutch pumps after each empty/refill of the reservoir. He was a Drag Racer and you could see the clutch particles in the fluid and the reduction when completed. There are videos of his work.
Second: GM says the black color from staining with the materials in the seals. I assume they contain carbon or moly disulfide etc, which are both black. So frankly I don't let the color cause me to make a change.
I have been using the method at oil changes for yeas in my C6, 2014 C7 and Grand Sport. For the last chage I bought that "brake fluid testing device" shown in post #22 because it was inexpensive and just for curiosity. As noted when I tested the first fluid I emptied it showed 3% moisture. At 4% it does require changing as that is the maximum where the additives used to manage moisture are no longer effective. Also the more moisture it contains also lowers it's boiling point. That is an issue with brakes.
First: the Ranger method says do 6 or 7 times with 30 clutch pumps after each empty/refill of the reservoir. He was a Drag Racer and you could see the clutch particles in the fluid and the reduction when completed. There are videos of his work.
Second: GM says the black color from staining with the materials in the seals. I assume they contain carbon or moly disulfide etc, which are both black. So frankly I don't let the color cause me to make a change.
I have been using the method at oil changes for yeas in my C6, 2014 C7 and Grand Sport. For the last chage I bought that "brake fluid testing device" shown in post #22 because it was inexpensive and just for curiosity. As noted when I tested the first fluid I emptied it showed 3% moisture. At 4% it does require changing as that is the maximum where the additives used to manage moisture are no longer effective. Also the more moisture it contains also lowers it's boiling point. That is an issue with brakes.
I could see having to do it 6 or 7 times mostly because of how small the bowl is. Doing it once a year or every oil change doesn't sound like a lot of work if it keeps your clutch working properly and avoids costly future repairs.
My C7 is now 5 years old (!) and has just short of 16k miles. All services have been done by the dealer, and at no point have they suggested changing the fluid.
My C7 is now 5 years old (!) and has just short of 16k miles. All services have been done by the dealer, and at no point have they suggested changing the fluid.
This is from your Owner's Manual.
One reason I do my own maintenance.
Hope they don't tell you you need a new master and slave cylinder when you have trouble. The $4200 a Poster said he was just quoted is high!
I perform the ranger method every time I change my oil (once per year). I use the whole container for flushes. I usually get about 6 flushes but the fluid is clean after the 3rd or 4th flush. I use the whole container because I won't save it after opening due to moisture contamination. This method does not flush the entire system but I believe the fluid is much cleaner by doing this every year. When I had my car in the dealership for an inspection the first year I bought it (car was 3 years old) I asked them to flush the system. They said that was an expensive job for the reason's others have listed above and said they would do the ranger method. I said I would do it myself if that was all they recommended.
Doing it once a year or every oil change doesn't sound like a lot of work if it keeps your clutch working properly and avoids costly future repairs.
I've done it about six times since buying the car new 20 months ago, one reservoir dump and fill per session except the first, which was several fills until the fluid looked clear. Thereafter just once since the fluid never looks contaminated or particularly dark. No fixed schedule, just whenever the spirit moves me.
I'm new to this C7 so I just looked at the bowl and was surprised at how small it is. Not only that but it's black and you can't see the color of the fluid. I'm thinking you would have to do the ranger method several times to see positive results.
My bought new M7/C7's bowl/reservoir was not only on the low on fluid side, but putrid as the color of chewing tobacco spit, with stuff floating on top of the fluid! I got my *** in gear, got in the game
with a bottle of Preston full synthetic DOT 4 brake fluid from Walmart Supercenter automotive dept, and a small suction turkey baster. My C7 had only a couple thousand miles on it too!
Hmm, "stuff" floating around sounds like Ranger shows in his videos he gets drag racing! That could well be small pieces of the clutch! Ranger developed hat method and used it after each race!
My bought new M7/C7's bowl/reservoir was not only on the low on fluid side, but putrid as the color of chewing tobacco spit, with stuff floating on top of the fluid! I got my *** in gear, got in the game
with a bottle of Preston full synthetic DOT 4 brake fluid from Walmart Supercenter automotive dept, and a small suction turkey baster. My C7 had only a couple thousand miles on it too!
Still going 30,000 miles between oil changes though?
Hmm, "stuff" floating around sounds like Ranger shows in his videos he gets drag racing! That could well be small pieces of the clutch! Ranger developed hat method and used it after each race!
With 25 miles on the car when I bought it, it sure was not the excessive mileage or usage factors. The car was going on 2 years old by the time I opened the reservoir to view it. BTW, the OLM, still has not timed out on my bought new C7. Going on 28 months since manufactured! . Figure that one out?!
.That said - I saved so much off MSRP on the car, the cost of the
Prestone isn't breaking me financially. Ha!
Last edited by Skid Row Joe; 11-10-2018 at 03:30 AM.
I had mine changed yesterday at my dealer. $240 as it was 2 hours labor. Had to lower exhaust to get at bleed valve ...y.
Originally Posted by JerryU
The GM proceedure in the Owner’s Manual calls for draining from the slave cylinder every 2 or 3 years depending on the year. Don’t know why it is deiffernt in the 2014 and 2017 Owner’s Manuals but it is.
Originally Posted by JDSC7VETTE
2019 says change clutch fluid every three years and brake fluid three years. No mileage numbers for either.
Yep as I noted in the above post, early C7's were 2 years, later 3 years with no apparent differences.
However those are full drains from the slave cylinder drain valve that requires removal of the left exhaust and CAT etc. As noted above it cost that poster $240.
Since the OP said his was 5 years old assumed a 2014.
So far an inexpensive easy Ranger Method every oil change has worked for me for over 10 years in C6 and C7's.
2019 says change clutch fluid every three years and brake fluid three years. No mileage numbers for either.
If you're only taking your C7 to the Chev. dealers for service - you're wasting your time on this DIY/Tech subject. They're not going to be helpful to maintaining your C7, as most of us are doing just that - DIYing what we can.
Yep as I noted in the above post, early C7's were 2 years, later 3 years with no apparent differences.
The clutch fluid and the brake fluid is the same stuff yet the time periods listed at 2 years vs 10 years is radically different! Seems changing the brake fluid every 2 years would be way more important then changing the clutch fluid.
Originally Posted by JDSC7VETTE
2019 says change clutch fluid every three years and brake fluid three years. No mileage numbers for either.
This is a much better maintenance plan since both these fluids attach water which is not something you want in either system.
The clutch fluid and the brake fluid is the same stuff yet the time periods listed at 2 years vs 10 years is radically different! Seems changing the brake fluid every 2 years would be way more important then changing the clutch fluid.
Interesting point. Can only speculate as to why the brake fluid 10 year recommendation. The 20 pistons (in the case of my Grand Sport) have seals that really don't slide! The pads are very close to the rotors and the square "O" ring doesn't move or slide they distort (see pic below and although it is for a lower cost single side piston system the seals operate the same in the C7.) That in fact is what "pulls" the piston back every so slightly so the pads don't rub with any force on the rotor causing drag. That "no/low" drag apposing piston design is used on all C7s. That seal reduces water intrusion and entrance of brake dust etc. Note when the pad wears enough the piston will slide on the seal surface that that does not happen often.
The clutch slave cylinder moves a significant distance so it's seals deal with a large movement an accumulation of clutch dust on the moving parts.. That is what gets the worn clutch disk "stuff" to enter the fluid a well as moisture.
All that said many European cars say change brake fluid every ~3 years!
Frankly I was surprised when I checked the clutch fluid in my Grand Sport after a year and the moisture was 3% (see post #22.) If the brake fluid moisture was that high it should be changed. I did not check it as I don't like to open that cap!
If you're only taking your C7 to the Chev. dealers for service - you're wasting your time on this DIY/Tech subject. They're not going to be helpful to maintaining your C7, as most of us are doing just that - DIYing what we can.
Who said anything about taking my car to a Chevy dealer for service?
have you tried this on a c7? I tried this and the fluid never circulated.
Been using the Ranger Method on my September 2013 built C7 M7 and my Grand Sport.IMO with the 210+ clutch pumps after empytying then filling the reservoir I am confident it mixes sufficiently.
Did the same for 6 years in my C6. If you look at the Ranger original video’s he shows the perticle reduction. I don’t find particles but unlike Ranger I am not at the drag strip all the time!
Look at my post #22, It shows mixing IMO. However, some are always doubting Thomases that need to put their hand in the wound! So BeIt!
FWIW, performed the Ranger Method at a one year oil change in my Grand Sport. Had also purchased a device that measures brake fluid moisture level so had a chance to test as I emptied the reservoir, pumped 30 times and refilled.
Here are the results:
First look at the color of the clutch fluid. Note by 7 changes it looks like the fluid in the container. (Note, buy a small container of DOT 4 fluid for ~$5 as once open and the metal seal broken it will allow moisture to enter! Screw caps do not provide 100% protection from moisture permeation once the foil seal is broken! Plastic is also permeable. You'll need all of it to perform 7 to 8 changes.) Then look at the meter reading, which measures % moisture. 3% moisture can be tolerated without that forming compressible steam when you apply the brakes! Over 4 it should be changed. The second thing the % moisture progressively gets lower until at 7 changes it is zero = to the value in a new container. IMO it proves the fluid in the reservoir does mix with the fluid in the lines and to some degree the slave cylinder. (BTW, only paid $2.50 on eBay for that meter delivered from China! Scary cheap. Same one is ~$10 on Amazon! I only bought for a fun test- I was planning and will use the Ranger Method at every oil change. It's simple. Empty the reservoir with a syringe, and fill with new fluid. Then pump the clutch 30 times and repeat.) Have been using the Ranger Method since I got my 2008 C6, on my 2014 C7 and now my Grand Sport. May not be as good as draining from the slave cylinder but much easier and cheaper! It's simple: This is a PDF on what I did on my 2015 C7: http://netwelding.com/Clutch_Fluid.pdf
cool. but I tried it at 30k miles after much hard driving. Reservoir was black. emptied and put new liquid. pumped about 50 times, liquid that came out next time was brand new, tried again, pumped another 30-40 times, still brand new. Drove 1 day, black again. So I don't know how I could have done it wrong but there it is. That was my experience.
11-08-2018, 10:20 AM
