[Z06] Clutch fluid recommendations
Dogface
Joined: Jul 2004
Posts: 25,974
Likes: 120
From: At the Beach, FL
St. Jude Donor '15, '17
That's interesting. I use Valvoline Synpower in my clutch reservoir and it doesn't leach to black at all. The fluid in the syringe in your picture looks horrible. I've never even been close to fluid that dirty.
I don't use the ATE SuperBlue because over time it stains the reservoir. I know it's popular to use the Blue then on the next brake flush use Gold so you can see when you're completely flushed. I don't do that. I was using Motul RBF600 in brakes and clutch but it has a caramel color and is hard to tell when it is dirty in the clutch. Easy to tell when you cook it on track and bleed some off the calipers.
I do about 8 HPDE(s)/year and my clutch fluid never looks nasty after an event. Just a little darker and there is a bit of dark crap in the bottom of the reservoir. Suck it all out and wipe clean and refill. So far I have no clutch problems.
I don't use the ATE SuperBlue because over time it stains the reservoir. I know it's popular to use the Blue then on the next brake flush use Gold so you can see when you're completely flushed. I don't do that. I was using Motul RBF600 in brakes and clutch but it has a caramel color and is hard to tell when it is dirty in the clutch. Easy to tell when you cook it on track and bleed some off the calipers.
I do about 8 HPDE(s)/year and my clutch fluid never looks nasty after an event. Just a little darker and there is a bit of dark crap in the bottom of the reservoir. Suck it all out and wipe clean and refill. So far I have no clutch problems.
Last edited by dwjz06; Mar 19, 2007 at 09:00 AM.
Racer
Joined: Dec 2006
Posts: 346
Likes: 0
From: Atlanta, GA
I've tried
GM-branded DOT4, OK but hard to find and expensive
ATE SuperBlue Racing DOT4; too dark to reveal a color change when degraded.
Valvoline Synpower, dislike this fluid as it leeched to black almost immediately.
Prestone DOT4 Synthetic, my favorite. Good quality, not expensive, widely available.
For those researching clutch pedal issues, here are five clutch fluid threads to review:
Here is the protocol in brief.
links to the original threads.
Clutch Pedal Woes--Fluid Impact
Clutch Hydraulic Fluid--the Chevy Spec
Clutch Pedal Woes--Fluid Changing Kit
A Pictorial On How to Clean Out the Clutch Fluid Reservoir
Ranger
GM-branded DOT4, OK but hard to find and expensive
ATE SuperBlue Racing DOT4; too dark to reveal a color change when degraded.
Valvoline Synpower, dislike this fluid as it leeched to black almost immediately.
Prestone DOT4 Synthetic, my favorite. Good quality, not expensive, widely available.
For those researching clutch pedal issues, here are five clutch fluid threads to review:
Here is the protocol in brief.
links to the original threads.
Clutch Pedal Woes--Fluid Impact
Clutch Hydraulic Fluid--the Chevy Spec
Clutch Pedal Woes--Fluid Changing Kit
A Pictorial On How to Clean Out the Clutch Fluid Reservoir
Ranger
Instructor
Joined: Jan 2007
Posts: 125
Likes: 0
From: Near Tucson AZ
So far I've done two iterations of the method using Prestone DOT3 Brake Fluid. First time I opened the lid to check it out it was definitely black with a few granules built up on the rubber condom looking seal. Car had 19425 miles on it.
I changed it using a syringe and a funnel. After about 10 days I changed it again using the method. I would estimate that it was 70% clear, changed at 19500 miles.
I checked it tonight (about 6 days since last change), and now it is about 90-95% clear, car is now at 19550 miles.
Seems to be working great, I'm just wondering how long on average it takes to start seeing the murkiness build up again. I'm going to leave it alone now until I see it get down to 75% clarity or so.
Kind of odd seeing it this clear, this fast, knowing that I haven't cycled out the entire amount of fluid yet isn't it? By the way how many changes does it take to do a complete cycle-flush? I estimate that I'm adding about 1.5-2.0 ounces of DOT3 each change, putting it right where the rubber condom displaces the fluid to max without overflowing the reservoir.
I changed it using a syringe and a funnel. After about 10 days I changed it again using the method. I would estimate that it was 70% clear, changed at 19500 miles.
I checked it tonight (about 6 days since last change), and now it is about 90-95% clear, car is now at 19550 miles.
Seems to be working great, I'm just wondering how long on average it takes to start seeing the murkiness build up again. I'm going to leave it alone now until I see it get down to 75% clarity or so.
Kind of odd seeing it this clear, this fast, knowing that I haven't cycled out the entire amount of fluid yet isn't it? By the way how many changes does it take to do a complete cycle-flush? I estimate that I'm adding about 1.5-2.0 ounces of DOT3 each change, putting it right where the rubber condom displaces the fluid to max without overflowing the reservoir.
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 31
From: Central Florida
...Seems to be working great, I'm just wondering how long on average it takes to start seeing the murkiness build up again. I'm going to leave it alone now until I see it get down to 75% clarity or so.
Kind of odd seeing it this clear, this fast, knowing that I haven't cycled out the entire amount of fluid yet isn't it? By the way how many changes does it take to do a complete cycle-flush? I estimate that I'm adding about 1.5-2.0 ounces of DOT3 each change, putting it right where the rubber condom displaces the fluid to max without overflowing the reservoir.
Kind of odd seeing it this clear, this fast, knowing that I haven't cycled out the entire amount of fluid yet isn't it? By the way how many changes does it take to do a complete cycle-flush? I estimate that I'm adding about 1.5-2.0 ounces of DOT3 each change, putting it right where the rubber condom displaces the fluid to max without overflowing the reservoir.
Regarding the fill line, you can feel the line with your finger inside the reservoir. You want to fill just up to that line.
Ranger
Racer
Joined: Feb 2007
Posts: 251
Likes: 0
From: Springdale AR
i'm about to do this too... changing brake and clutch fluid. i thought i read somewhere that this condom thing had to be collapsed into the screw-on cap to the reservoir before replacing the cap. i'm a dummy and not sure exactly what this rubber piece does. ive seen them in brake fluid reservoirs too.
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 31
From: Central Florida
^^^ The rubber fitting is intended to reduce abrupt changes in (e.g. buffer) available volume for the closed hydraulic system during abrupt transitory movements by the car. Examples are strong shifts or high G-force turns.
Yes, the rubber fitting is supposed to be collapsed inward before the cap is replaced.
Ranger
Yes, the rubber fitting is supposed to be collapsed inward before the cap is replaced.
Ranger
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Instructor
Joined: Jan 2007
Posts: 125
Likes: 0
From: Near Tucson AZ
^^^ The rubber fitting is intended to reduce abrupt changes in (e.g. buffer) available volume for the closed hydraulic system during abrupt transitory movements by the car. Examples are strong shifts or high G-force turns.
Yes, the rubber fitting is supposed to be collapsed inward before the cap is replaced.
Ranger
Yes, the rubber fitting is supposed to be collapsed inward before the cap is replaced.
Ranger
