Viprklr

I would like to change mine out. Anyone recommend a certain brand? Is it DOT 3? Thanks! :cheers:

ZO6LS6

Viprklr, I use Valvoline Syntec........Dot 3 & 4 approved................

Ranger

Viprklr,

There are a lot of choices. Spec is DOT-3; I upgraded to DOT-4 (ATE Super Blue Racing) to get its higher dry and wet boiling points. Here are some links to useful info on brake fluids (same as clutch hydraulic fluid). The system holds about half a liter, so cost isn't a driver.
http://www.rpmnet.com/techart/fluid.shtml
http://www.shotimes.com/SHO3brakefluid.html
http://www.brickboard.com/FAQ/700-90...mparison.shtml

Ranger

SDVette

Viprklr,

I was told to use the GM "Hydrolic Clutch Fluid" because it has an additive to stop the pedal from squeeking. It's DOT3.

I run the Valvoline DOT4 in the brake system, but GM in the clutch.

Good luck,

Ranger

I was told the same thing and bled mine with DOT-4 anyway. The pedal only squeaked for the first few depressions and not at all since. That was four months ago. The high boiling point of DOT-4 has eliminated my pedal's tendency to stick to the floor when performing WOT runs through the gears. That was my objective in going to DOT-4. I also swap out the fluid in the reservoir a couple days after each visit to the dragstrip. This practice has kept the boiling point near spec for DOT-4.

Ranger


[Modified by Ranger, 8:43 PM 1/21/2002]

Viprklr

Thanks to all. :cool:

Ranger, what is your procedure for swapping out the fluid. Do you use a mighty vac, or bird baster? Would appreciate the info. :cheers:


[Modified by Viprklr, 8:34 PM 1/22/2002]

Ranger

The process I follow takes about 3-4 minutes. I use paper towels to sop up the fluid readily accessible in the reservoir (under the hood), being careful to get the wet towels immediately into a prepositioned plastic bag. I wipe down the sides and bottom of the reservoir to remove the black bits and goo that inevitably collect after time at WOT, and then refill it with fresh DOT-4. Also I wipe off the rubber inside the cap.

Others following this general practice use a turkey baster or medical syringe to good effect and squirt the spent fluid into a soda can. But the paper towels work fine for me. Just need to keep in mind that brake fluid is corrosive and so watch for drips.

Ranger

Tracy

Ranger (and all who have discussed this fluid and M/C line issue for the past several weeks):

I just don't see what good it does to change the fluid in just the reservoir. It seems to me that the "problem fluid", if you will, would be in the slave and/or in the line, or perhaps the M/C itself. Doesn't the fluid in the res just sit there, for the most part? Maybe a little up and down as you work the clutch, but no circulation to speak of. I mean, it's a closed system. You could pour cat pee into the res and it wouldn't get down to the slave for a long, long time.

My point in this is to say that I think proper and EFFECTIVE replacement/flushing of the clutch hydraulics requires the labor-intensive effort of bleeding the system at the slave bleed fitting, exactly like you would do for a brake system.

Am I wrong here? It would be good if I was!!

rwj383

[QUOTE] You could pour cat pee into the res and it wouldn't get down to the slave for a long, long time.
QUOTE]ROFLMFAO!!!!!!
Hey, i would like to have someone post the proper procedure myself as i just replaced my line with a modded line sans restriction. though i primed the line before install, i would like to bleed it anyway with new fluid. anyone have the procedure handy?

Ranger

tracy,

I'm short of time right t the moment. So excuse my brevity.

There is no question about the recirculation of the fluid. How else would the black bits and goo wind up in the reservoir? They obviously are not created there. The problem I see is that the fluid gets cooked from high temp. and simply breaks down.

Bleeding the clutch hydraulics is the best answer, but cost me $100 in labor. On an ongoing basis, I now swap the fluid in the reservoir to keep it fresh. This approach has worked for me so far to avoid pedal issues, and it works for PowerShifter who follows the practice and has not had his bled, so far as I know.

Ranger

Godspeed

I run Motul 600. :cheers:

-Jeremy

George Cooper

There was a pretty good post about this here a while ago, and I copied it. I am only sorry that I don't remember who posted it:

"There are a couple of ways of doing this, the good easy way, and the really hard proper way. The latter is effectively impossible (Bleeding the clutch the Òproper wayÓ requires access to the bleeder valve. Unfortunately, getting at the bleeder valve requires removal of the exhaust [collector to the cat-back] and the central underpan with its many fasteners. The bleeder valve itself cannot be seen, only felt unless you use a mirror.). The easy way is as follows: take a turkey baster and remove fluid from reservoir; take a clean, lint-free cloth and clean out the crud, fill with Dot 4, which is better than Dot 3 and compatible with the Dot 3 in there now. Drive and repeat as fluid gets dark again."

I recently did this using the Valvoline SynPower High Performance Brake Fluid that meets DOT 3 & 4 specs and is compatible with any of the DOT 3 stuff out there - get it cheap by the quart anywhere. The fluid was pretty clean after 3 cycles of this hoo-haa. Just be careful with the fluid - it'll take your paint off if you don't get any spills off promptly.

Tracy

Ranger,

I just don't know how this goo gets there, or what the goo really is. Is it bits of rubber? [can't be, right?] Burnt fluid? Maybe. Contaminated fluid (moisture)? Very possible. I'm aware that you've solved a problem by doing this and there ain't no disputin' success!! And there's no point in having goo in there, whether the fluid recircs or not. I seriously don't think it recircs, but perhaps it "migrates". Regardless, you have established a specific maintenance program and are monitoring the encroachment of goo into your resv, so we know it's getting in there somehow.

Another method of partially flushing/bleeding the system is to pop the Quick Disco fitting, slightly push on the wafer valve in the end of the disco with a matchstick while the wife (well, maybe your local Vette buddy) gently pushes the clutch in much the same manner as the brake pump/bleed/pump/bleed procedure. Release the wafer before your helper releases the pedal, of course. Could be messy. Again, this won't do anything for that cat pee that has made its way to the slave cylinder (actuator in GM-speak), but it will allow you to really clear out the resv and the MC.

I'm thinking along the lines of Castrol LMA [low moisture absorbtion]. I don't think we need the high heat capabilities of the better brake fluids, as the slave doesn't see hellish temps like calipers do. But the absorbtion of moisture over a short time [even the best racing fluids do this quite rapidly. In fact, I think the racing fluids do it fastest!!] could be the source for Ranger's goo.

kewlbrz

David Dilusi (from dilusi brakes) recommended and uses castrol LMA.

Ranger

At a recent shop night at our local Corvette club, we randomly checked the clutch hydraulic reservoir on six M6-equipped C5s. All showed a significant build-up of debris, black bits and goo. So it definitely is coming from somewhere. Moisture is possible. So is heat from exhaust manifolds/headers etc.

I changed the Super Blue Racing fluid (DOT-4) in my reservoir yesterday at shop night. The inside of the reservoir was coated in black slime. But no serious goo or black bits. I had about 10 drag runs on that fluid and about 1500 miles of my "normal" driving. This is the least build-up of contaminants that I've seen since I began watching it. Definitely far less than when running the stock DOT-3. My clutch pedal is still normal.

Ranger


[Modified by Ranger, 7:04 AM 1/28/2002]

bigDvette

I'm new to the forum. Bought a 2000 Black Vette with 7000 miles on it in mint condition. I've been reading on the forum all the fluid changing and jacking threads and the information is great. I decided to test the clutch fluid replacement technique with my turkey baster (well battery water filler). I changed out the fluid in the res. and decided I would just take the car for a 5 mile spin (2.5 each way to home depot to make my hockey pucks) . Now, with that amout of time I don't think moisture or heat could play a role in changing the fluid. So when I got home, I opened it back up and the fluid in the res. was dark again. I pulled it out and there was a lot of stuff in there again.

I noticed this time when I sucked out the fluid, that the fluid in the line mixes pretty easily with the res. fluid simply by causing some back pressure with the baster over the line and the old fluid swirls up.

In any case, I'm going to try this method for a few weeks and see if the fluid gets clearer and clearer. Anyone know how much fluid it takes to bleed and fill the system, that will give me some idea when I've added as much as it would take to bleed and by then I should start to see a real difference in the clarity of the fluid.

I think the clutch must create pressure that pushes and pulls liquid in and out of the res, while keeping the overall level constant.

:cheers:

Ranger

Good observations BigDvette. The capacity of the clutch hydraulics is about 16 ounces. The shop manual is mute as to a specific capacity, favoring the term, add fluid, "as needed" when bleeding the clutch.

Ranger

Bluvette1

I use the Valvoline Dot 3 & Dot 4, read the bottle and compare great stuff !!!