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Just checked my clutch fluid to see how dark it was as the reservoir is black and not see thru... wow..level was very low. 13,500 mile Z51 delivered 9/03/16. No visible leaks anywhere and clutch operates fine.
Anyone has experience of this type?
Yup, the clutch fluid gets dark very easily due to clutch particles working their way past the rubber seals. Low fluid is bad though. Use the ranger method shown above to flush the fluid. I plan to do it yearly.
Just checked my clutch fluid to see how dark it was as the reservoir is black and not see thru... wow..level was very low. 13,500 mile Z51 delivered 9/03/16. No visible leaks anywhere and clutch operates fine.
Anyone has experience of this type?
As posted above, I use the Ranger Method every oil change (which is usually once per year.) Easy to do by yourself and perhaps not as good as the recommend bleeding and replacing the fluid every 3 years, it has worked for me. To access the clutch bleed screw you have to remove and exhaust pipe etc! Dealers charge $125+ so doing the Ranger Method every year is cheaper! I have used it on my C6 and 2014 C7 and never had to use the formal bleed method. All have been fine.
Some of that color is due to contamination but GM says the black color is also caused by the seals. Not sure if they are carbon but it does turn black quickly. Don't replace the fluid just for color.
As posted above, I use the Ranger Method every oil change (which is usually once per year.) Easy to do by yourself and perhaps not as good as the recommend bleeding and replacing the fluid every 3 years, it has worked for me. To access the clutch bleed screw you have to remove and exhaust pipe etc! Dealers charge $125+ so doing the Ranger Method every year is cheaper! I have used it on my C6 and 2014 C7 and never had to use the formal bleed method. All have been fine.
Some of that color is due to contamination but GM says the black color is also caused by the seals. Not sure if they are carbon but it does turn black quickly. Don't replace the fluid just for color.
I know that Ranger proved by analysis the contamination was from clutch dust, but I have never seen anything from GM or anyone else that claims it is deterioration of seals. Where did you get that information? It can get dark very quickly and I can't believe it is because the seals wear that quickly.
I know that Ranger proved by analysis the contamination was from clutch dust, but I have never seen anything from GM or anyone else that claims it is deterioration of seals. Where did you get that information? It can get dark very quickly and I can't believe it is because the seals wear that quickly.
Recall the issue being addressed when I had my C6.
This is one GM Bulletin on the subject:
#PIP4938: Discolored Dirty Dark Sludge And/Or Grease In The Clutch Fluid Reservoir - (Aug 4, 2011)
Subject: Discolored Dirty Dark Sludge and/or Grease in the Clutch Fluid Reservoir
Condition/Concern: It may be observed on some vehicles that the clutch fluid in the reservoir appears to be discolored, dirty, have sludge or grease contaminates in it after being in service for a period of time.
The level of discoloration will vary with factors such as driving conditions, under hood temperatures etc. This is a phenomenon that may occur with time due to the interaction between the clutch system rubber parts and hydraulic clutch fluid. Comments have been received about the fluid in the hydraulic clutch system being discolored. This discoloration is the result of carbon black used in the seal manufacturing process leaching into the hydraulic fluid used in the clutch system. The discoloration may also collect on the inside of the clutch reservoir at the top of the fluid. This discoloration does not affect the operation of the clutch system and should not be considered a reason to flush the clutch hydraulic system
The current Owner's Manual just says: "The fluid will darken over time. See Maintenance Schedule 0 299 for when to replace the fluid." But no explanation as to why.
Bottom Line; Don't think it is the seals deteriorating it's just that brake fluid apparently dissolves the carbon black pigment in the seals.
Just checked my clutch fluid to see how dark it was as the reservoir is black and not see thru... wow..level was very low. 13,500 mile Z51 delivered 9/03/16. No visible leaks anywhere and clutch operates fine.
Anyone has experience of this type?
Was this first time you checked fluid level? I was very surprised to find in OM that the proper fill level is to the MIN line, not to where rubber boot is when pushed into cap recess or just 1/2" to 1" below top of reservoir. Explains why unlike most fluid reservoirs there is no MAX line.
Last edited by madrob2020; 01-20-2018 at 09:31 PM.
Was this first time you checked fluid level? I was very surprised to find in OM that the proper fill level is to the MIN line, not to where rubber boot is when pushed into cap recess or just 1/2" to 1" below top of reservoir. Explains why unlike most fluid reservoirs there is no MAX line.
I have a max line on mine. Not sure why they would be different. I guess I will have to watch the level closer. Used the ranger method on my C6 but never thought my C7 level would be so low. Made a mistake thinking my dealer checked it when servicing my car.
Was this first time you checked fluid level? I was very surprised to find in OM that the proper fill level is to the MIN line, not to where rubber boot is when pushed into cap recess or just 1/2" to 1" below top of reservoir. Explains why unlike most fluid reservoirs there is no MAX line.
Just reread the owners manual on the clutch fluid AFTER reading your post. If true as stated, fill only to the "min" line....than my fluid reservoir really WAS NOT low as I thought. Just curious why GM/Chevrolet would change the fill level on this car and make it different the my C6. Why?
Just reread the owners manual on the clutch fluid AFTER reading your post. If true as stated, fill only to the "min" line....than my fluid reservoir really WAS NOT low as I thought. Just curious why GM/Chevrolet would change the fill level on this car and make it different the my C6. Why?
Maybe someone who "KNOWS" will answer this. Expansion? Larger clutch cylinder?
Hmm, that is what the OP started this Thread saying! If you read the posts and his later comments re amount, you'll see the level was fine! It is only supposed to be filled at the Min line. That is about 1 inch below the top.
As far as color, see my post #7 re what GM says in a Bulletin about color. If you have particles like shown in the Ranger Method web site that is different than just a dark color.
I used the Ranger Method at every oil change in my 2014 C7 Z51 (~ once/year.) Much easier and cheaper than what a dealer will charge (> $125+!) If you read Note 7 on the Service and Maintenance Chart (page 11-8 ) of the 2014 Owner's Manual it says you are to have it flushed every 2 years (current Owner's Manual says every 3 years.) That requires removing an exhaust pipe, primary CAT and a plate covering the throwout bearing area! That procedure is outlined in the PDF mentioned below taken from the Service Manual. Not an easy DIY! Ranger Method is a DIY procedure and has worked for in my C6, C7 Z51 and will do it on My Grand Sport.
If interested, this is a 7 page PDF with lots of pics of what I did and the results.
Put one pic (of ~15) from the PDF below:
Left is what clutch fluid looked like after 1 year. Right, after the 6th drain using the Ranger Method; 1) empty the reservoir, 2) refill with new fluid and 3) pump the clutch 30 times- it looked like the fluid in a new container. Easy to do the Ranger Method.
I have been using the Ranger Method on my Corvettes for many years. Cannot believe it would be proper to fill to min line and not max. When you pop the cap off it looks low to me.
BTW, when I first saw that GM said to fill to min. line, I asked a friend of mine to check his brand new Grand Sport, and it was half way between the upper and lower limits.
01-20-2018, 01:16 PM
Clutch fluid
Maybe someone who "KNOWS" will answer this. Expansion? Larger clutch cylinder?
