Is my clutch fluid low?
 

I was going to try the Ranger Method, and opened it to see this - does this look low to you? Is there an indicator to look at for measuring full vs. empty? Any feedback would be most appreciated...:thumbs:

https://cimg5.ibsrv.net/gimg/www.cor...4a95262965.jpg

I'm confused... NOT hard to do... But, there is a reservoir for clutch fluid??? I've never heard of such a thing. Only driven manual transmissions--never needed to monitor or fill or refill clutch fluid...

Yes sir - its debatable if needed by folks here - but you cant argue that the end result of this video shows its cleaner once finished:

I am not going to get into the argument about continually flushing the brake fluid. You have an issue and it isn't bleeding or how clean the fluid is. The reservoir is empty and it shouldn't be empty. At least get some fluid in it to fill the reservoir to the minimum level line. What ever caused the fluid to drop that low may need to be addressed. Have you noticed any problems with the clutch recently? The problem could be a leak or clutch wear. Fill the reservoir and keep a close eye on the level. If it drops down quickly you may have a leak in the system.

Bill

I just completed the Ranger Method. Very easy to do by the way. My reservoir is now full and the DOT 4 fluid is super clean. Ill keep an eye on it for the next few days and if the level drops Ill bring her into the shop. FYI - right or wrong, I just wanted to do the Ranger Method since I have 38k miles on my C7.

May I ask what the clutch would feel like if it was low or had a leak? Would I feel anything in the gears while shifting?

Thanks for everyone's help! :thumbs:

I'm going out on a limb here-CRAP. I believe once the fluid drops below the intake (hole you can see in pic) opening you will have air in the system which can cause shift problems & possibly a clutch that is slow to return to up position or fail to return up. I'm basing this on a '85 S10 Blazer that kept losing fluid at the piston coming thru the firewall. The piston had minute burrs which eventually wore out the inner seals allowing fluid to seep past them. Just for grins, check under carpet/foam below where clutch rod comes thru firewall. Technology has come a long way since "85 but just saying.

OK....... So, Bill Dearborn - what should/does normal look like when opening up the clutch fluid reservoir?

1) Have you never checked the clutch fluid reservoir fluid level until a day or so ago? In 38k miles?

2) A photo of the full fluid level would show the comparison.

​​​​​​​Rx?
3) I'm getting a stuttering/pulsating engagement of the clutch drive at slow engagement and low RPMs, in a parking situation. It started this in March, with about 1,000 miles on the.C7.

Yep, very low. Should have dealer look for a leak! The proper level is ~1 inch from the top. You are close to pulling air into the system. Air is compressible and when you push on the clutch pedal instead of fluid operating the master and slave cylinders the air will compress. No clutch operation!

For the poster who did not know there was a hydraulic fluid reservoir, I did not have one on my '41 Ford, '50 Ford or CJ5 Jeep either! They did not have hydraulic throughout bearings. Just mechanical linkage. If you have a hydraulic throughout bearing it has a master and slave cylinder like brakes and a reservoir!

For those who don't believe you need to change the clutch fluid-the Owner's Manual says to have the system bleed every 2 or 3 years depending on what year C7 you have- look in the Owner's Manual. Below are some pics of the fluid appearance after a Ranger Method change in my Grand Sport, which I do at each oil change. Easy and cheap.

The Ranger Method is not as good as a bleed but that requires removing the driver's side exhaust pipe and CAT as well as the sheet metal cover under the clutch! Some dealers charge ~$200. I used the Ranger Method for 6 years on my C6, 3 1/2 on my 2014 Z51 and once on my Grand Sport. Never an issue. You can see by the fluid color change with progressive reservoir changes and 30 clutch pumps after each. The fluid does mix with that in master cylinder, the line and to some degree the slave cylinder. Not 100% but good enough, IMO.

Bought a brake/clutch fluid moisture meter (from China <$3 delivered!) for fun to check the level. Anything above 4% and in a brake system it could cause boiling under severe use! But note the color after each fluid change. The new reservoir fluid does mix to some degree with the fluid in master cylinder, line to the slave cylinder and the slave cylinder itself (the hydraulic piston that moves the throuhout bearing.)
https://cimg3.ibsrv.net/gimg/www.cor...3545700283.jpg

I agree 100% with JerryU - Thank you for sharing your findings.

As for the fill levels - here is a picture of the reservoir filled and then a picture of how it looks with clean DOT 4 - before I did the Ranger method I could not see that intake/hole at the bottom and what I took out during the Ranger Method was dark dark brown until about the 5th time doing it:

https://cimg5.ibsrv.net/gimg/www.cor...4728d65fef.jpg
https://cimg8.ibsrv.net/gimg/www.cor...df1610856f.jpg

I thought the clutch system needed super dot 4 brake fluid not just dot 4. :flag:

Yes, Super DOT4 is what GM uses. Pentosin makes it. From what I can see it has a lower viscosity than other brake fluids which might reduce some of the other problems with the clutch pedal getting stuck as the fluid will move through the plumbing easier. Unlike a brake system where little fluid movement occurs a clutch sees far more back and forth fluid movement.

Bill

I used Prestone DOT 4 Synthetic Brake Fluid - many of the videos online showed this product...

What was your methodology with each fill and flush? Did you seal the reservoir with it's cap, 4 or 5 times too? Or, did you change 4 or 5 times, never re-sealing the reservoir?

Good pics. See now what I thought was almost an exposed hole into the master cylinder was looking through clear new brake fluid!

Just a note about brake fluid color. There was an older GM bulletin that mentioned the dark color comes from (or probably partially comes from) discoloration by seals. Assume those are the seals at the slave cylinder. One source said it was nitrile butadiene rubber seals. Since brake/clutch fluid is a good paint remover, assume it can partially dissolve or absorb most chemicals! :lol: (On page 237 or the 2017 Owner's Manual it states: "The fluid (clutch) will darken over time.") Some have expressed concern that the new fluid turns dark or black quickly. IMO that should not be a concern. As noted from my pics of fluid at various Ranger Method changes the moisture level started at 3%. Brake/Clutch fluid can tolerate up to 4% moisture but than should be changed (one old GM source for the C6 said change at 2% moisture.) It not only can boil at high temps (that temp is dependent on fluid type and reduces with moisture content) but it also causes corrosion.

Since GM says to fully replace with new fluid at 2 or 3 years depending on C7 Owner's Manual year, I feel the Ranger Method at each oil change is good enough for my street driving.

I have a '15 Stingray Z51 M7. During a routine oil change at the dealer they told me the clutch fluid was low. I bought the car with 6k miles on it and there is no record of any type of work related to the transmission or clutch. I have no indication that there is a leak anywhere either. The dealer topped it off and I checked the level a month later. Still full. I'm assuming it came from the factory low because I cannot identify any other reason why it was low.

1) No - I bought the car with 36K miles on her and just got around to checking the clutch fluid
2) Just read about it here on the forums and thought it would be a good time to do the Ranger Method since my car is 4+ years old and I dont know if it was ever done previously
3) Filled the reservoir to about an inch from the top, put the reservoir cap back on, pumped the clutch 30 times, removed reservoir cap, suctioned all DOT 4 brake fluid out, refilled the reservoir and repeated all steps 5 times in total (till the brake fluid going in was the same color I was suctioning out). I put the reservoir cap back on everytime before pumping the clutch 30 times
4) I cant comment on the fluid from Germany, but everyone I saw online or read about used either the Super DOT 4 or the Prestone DOT 4

I've got about 6k miles on my car and the fluid was filthy. Glad I checked it and did the Ranger method. It got dirty really quick. Worth a look.