My Z that i have had for the last month has some pretty black clutch fluid. Does this mean that it was raced or is this normal for a 40k car. Regardless I plan on changing fluid this weekend and I take the wife to see Beowulf in 3-d.

 

Normal, it will turn black again most likely after the first drive. Check Rangers change reccomendations. I change mine every 3-4 times I drive the car.

 

It was most likely that way before it had 10K on it..... doesnt take long at all to become nasty looking especially if its been driven aggressively. When Im not at the track I change mine about every 2nd gasoline fill up. At the track I watch it closely.....if it gets the least bit dirty it gets changed right away.

 

The main ingredient of the black in fluid is clutch dust that's expressed by the friction surfaces on launches and shifts, both up and down. That dust is drawn into the slave by the action of the seal during pedal articulation.

If the fluid is not changed frequently, the dust load becomes visible, turning the fluid murky and then progressively black. At that point it is sufficiently abrasive to attack the seals, causing them to eventually fail.

Moral: follow the procedure--
Taking Care of Your Clutch

Ranger

 

I followed Ranger's instructions to a "T" on my 19K car this past weekend. Took about three iterations until the fluid was clear. I even wiped down the inside of the reservoir with a lint free cloth. This process will be on my regular maintenance list from now on. Thanks, Ranger!

-Deano

 

i followed the same advice from ranger and my clutch fluid hasnt been changed in 3 months but is still incredibly clear...i was changin it everytime i was done driving for 2 weeks though guess it has to work its way out...hey ranger do u have any websites on complete fluid replacement ex. tranny, rear diff, fluid sorry to pirate ur post bro i think it would be good advice so u dont have to pay for every fluid change u wanna do also was wondering what type of fluid for tranny, rear diff

 

but how is this clutch dust getting drawn into a sealed hydraulic system? you would think if dust was getting drawn in that air & moisture would also, and fluid would be able to get out.

 

I'm not looking to get back into a long defense of my research on the issue. I'd suggest taking another look at the pictures of the clutch actuator (slave) posted by Chuckster.

The closed bell housing of an aggressively driven LS1/2/6/7, and presumably 3, is full of clutch dust that permeates the surface of all the parts inside the bell housing, including the wall of the cylinder that's in direct contact with the main seal. Scrubbing action as the seal moves will bring minute quantities of dust into the fluid on each stroke. That dust quickly imparts a cloudiness to the fluid. Over time the dust accumulates and participates in the master cylinder and actuator/slave.

I had occasion last Sunday at the track to help two F-body owners struggling with clutch pedal woes. Their fluid was black, heavy and very, very thick. Both were racers with a lot of passes on the clutches. My view is that the character of their fluid showed clutch dust.

Having worked the issue since 2001 and followed transition of GM's published view, I put little stock in the old explanation that discoloration originate in the carbon black of the seals themselves. The volume of fine black grit is too high, too thick and viscous to come just from inside the seals.

Keeping in mind too, no seal is perfect and the clutch master cylinder reservoir has three "one-way"vents. When I change the fluid in the reservoir and pump the pedal 20-30 times, I normally find a surprising volume of tiny air bubbles in the reservoir. Where does that air come from if the system is absolutely closed? I say at the same time those minute air bubbles have had zero impact on the behavior of my clutch which continues to behave normally at 100 passes.

Ranger

 

you say that like I've seen it before or something, I'm not trying to start an argument or attack you. relax, I just asked a question.

That actually makes sense, I never thought about the piston sleeve collecting dust. The only thing that still has me confused is that if there was enough room for the dust particals to get in there, then there is enough room for the fluid to get out. especially given the fact the fluid is under pressure, which should make it harder for dust particals to get in.

 

I don't buy that either. But it's posted on the internet so it must be true.

 

 

Here we go.

Having spent six years dealing with those who said degraded clutch fluid is irrelevant to the performance of the clutch, I'm not much dissuaded by those doubting clutch dust finds its way into the fluid when squeegeed by a tight seal sliding on a cylinder wall covered in clutch dust by every launch and shift.

Sorry for that paragraph crammed into a sentence.

Might want to talk with a few pro-stock crew chiefs and see if they ever see clutch dust in the fluid after a pass. Just a thought.

Ranger

 

Ok well, I have only owned the car for a month and it has 41k on it. The manual says not to worry about the clutch fluid but i think i will change it anyway. What brand/type do you recommend? DOT3 i assume.
I do not however think I will be changing it every 4-5 or times I drive the car as mine is a DD for now. Every oil change sounds about right for me.

 

GM is now recommending that the clutch fluid be changed at least every 24 months. That's a maintenance procedure change instituted in Sept 2007.

A procedure for changing the fluid and alternative brands are provided at the link in post #4 above.

Ranger

 

I thought Pro-Stock drivers had some kind of air shifting transmission, more like an automatic then a manual, with clutche(s) inside the transmission itself.

Also, if this truely is "clutch dust" that is making its way into the hydraulic system, then what about different types of clutches being used other then OEM - organic types. Like for example copper or other metalic type clutches. Some of them are so hard they actually wear in to the FW & PP before they start wearing on the discs themselfs. Unlike the soft organic compound which create more dust and don't usually gouge marks in the PP & FW friction surfaces.

I would suspect that you should see less of a problem with the fluid turning black on those (metalic) types of clutches if "clutch dust" was the real problem.

I'm just thinking out loud here...

 

Pro-stock cars use a clutch to launch.

The shifts occur without a clutch.