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Discussion Starter · #1 ·
There are two similar post to this below, you will do well to read them, but after this morning I decided to make a separate post pretty much in the same vein: forgive the redundancy but it is important.

Went down to where I keep the drag car this morning to add some Blendzall to my Methanol. While there I looked at my clutch master cylinder and the fluid appeared clean to the eye from the outside.

(Now C4's were famous for having slave cylinder issues and I was assured that this was fixed in the C6 ***and Hillary is a conservative***. IT ISN'T!)

I opened the master and the fluid was not contaminated, it was beyond contamination, it actually looked like it had different consistencies. IN OVER 40 YEARS OF MESSING WITH CARS I HAVE NEVER SEEN A FLUID SO CONTAMINATED!! I sucked out the old stuff, cleaned the ton of crud off of the cylinder lid boot and filled with Valvoline synthetic fluid. I went into the car and pumped the clutch 100 times and checked again and there were some particles in the master so I repeated the process.

I KNOW that in about 500 miles or so the stuff will be contaminated and I will give it that long and repeat the process until the stuff is clean or at least transparent. I intend to change this as a routine every 5K when I change the oil from now on.

Remember this: clutch engagement/shifting smoothness/take up are all controlled by the hydraulics and if contaminated by either water or other crud which usually comes from fluid depredation from heat your system is compromised. Being hygroscopic it will absorb water even if you don't drive in the rain.

Lastly, what fluid to use? I have a full bottle of GM # 12345347 (what they recommend): it's junk. I learned with the C4 to use the Valvoline dot 4 synthetic. I am sure there is better stuff but this works great for me.

Clutches and synchronizers are expensive and one of the threads below has a link to a great clutch fluid/care section - - all with manuals should read it.

Oh, I have 22K on my car. I hope this helps someone and I am curious as to how many open the clutch master cylinder and find this as I did.

Check it.
 

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I did the same thing last weekend and changed mine out a couple of times until it was basically clear again after pumping the pedal 30 times. I was amazed how much crap and droplets that looked like water were on the rubber seal. I used the same fluid as you did. Things are working a lot smoother now. Cheap and easy DIY. :thumbsup:
 

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yep, found the same thing after the infamous, stuck peddle to the floor syndrome. Luckily it came back up in time to shift into 2nd and blow the doors off that GT-500.

Since then, I religiously change the fluid weekly. Same fluid you use.
 

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Discussion Starter · #4 ·
JS & Mad,

If you clutch's hydraulics go up the creek because of the Valvoline don't blame me - - used it in my C4 for four years: stopped squeaking pedal and was MUCH cleaner to boot , , really!
 

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JS & Mad,

If you clutch's hydraulics go up the creek because of the Valvoline don't blame me - - used it in my C4 for four years: stopped squeaking pedal and was MUCH cleaner to boot , , really!
I wasn't worried before I read the above. Is there something I should know?
 

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Discussion Starter · #6 ·
Heck no - - just messin' with you guys: great stuff to use for the clutch's hydraulics.
 

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Discussion Starter · #8 ·
Because of the location, which is perfect access, you can use a turkey baster with no problems. As to refilling, just put it between the two marks on the master cylinder. In reality, you could probably just soak it out with the blue, lint free towels but it would be messy as hell.

I think the two most important parts are keeping lint etc. out of it when you wipe it out and NOT putting the GM fluid back into the clutch hydraulics.

Make sure none gets on your paint !!!!!!
 

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I use a Turkey Baster. I saw some discoloration with the GM fluid so I began Ranger's sucking the fluid from the resevoir and replacing it. After going road racing I have changed to Motul 600. I do not see the discoloration but maybe that is because the Motul has a color but I continue to change out the fluid regularly.

:cheers:
 

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Discussion Starter · #10 ·
I think as long as it is a quality fluid and changed on a regular basis one will do well with his clutch hydraulics - - biggest factor is the boiling point when there is water in the system.

That reminds me, time to change the brake fluid too.
 

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OLDDOG, was this the first time you changed the fluid at 22k miles? How much track time?

I agree that the fluid change is easy and cheap insurance. I'm my '04 Z06, I found that the motul fluid performed and held up better than any other fluid I tried. The only down side was that because of the color, some tracks wouldn't allow it to pass tech inspection the first time. after explaining the issue and showing it's color when new, it wasn't an issue.
 

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Discussion Starter · #12 ·
XX,

One or two passes down the drag strip about a dozen street events usually from a roll and that is it. It is a daily driver. Yes, first change out (not too smart sometimes)

For racing, I have what has become a race dedicated car especially now that we have converted it to methanol.

dog
 

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Discussion Starter · #15 ·
I have used the 'Valvoline Syn Power' full synthetic: Dot3/4 in the C4 and C6.

Seems to be quieter in the slave, has a much higher boiling temp when slightly hygroscopic and isnt the same junk GM uses . .
 

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I have used the 'Valvoline Syn Power' full synthetic: Dot3/4 in the C4 and C6.

Seems to be quieter in the slave, has a much higher boiling temp when slightly hygroscopic and isnt the same junk GM uses . .
cool i have this stuff in my garage, is it ok to use brake fluid that been sitting for a year or two?
 

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I have used the 'Valvoline Syn Power' full synthetic: Dot3/4 in the C4 and C6.

Seems to be quieter in the slave, has a much higher boiling temp when slightly hygroscopic and isnt the same junk GM uses . .
Not sure why you say GM clutch fluid is so bad. It is supposed to have additional friction additives that regular brake fluid does not have. I have used GM fluid in my 2004 Z06 and the fluid has never gotten dark.
I changed the fluid in the reservoir with GM fluid at 19,000 miles, but the fluid still looked clear. So far, it still does not look like it is breaking down, or turning dark.
By the way, you can order large syringes from medical supply houses on line for a more positive seal on drawing fluid out of the reservoir. Instead of metal needles, you can also get teflon or polypropylene sampling needles that attach to the syringe like the metal needles. They make it a little easier to get all the way to the bottom of the reservoir, especially for drawing fluid from the brake reservoir.
 

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Discussion Starter · #20 ·
VetteCsix is correct - - also, keep the brake fluid tightly sealed and in the house if you can: not in the basement unless in a warm area: you want it far from any moisture. If you are not sure about your fluid of of it is more than half empty get a new one: what is your clutch/tranny worth?

If you have someone you despise you can add an ounce of water and give it as a present (nasty - very nasty :devil: :surprised )

Seriously, use it, cap it tightly and put it in a heated/dehumidified environment like AZ.
 
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