Warp Factor: That was my point, 1st gens had no hydraulics and no self adjustig pressure plates. Biggest problem then was pressure plate over centering but you could compensate by making clutch release off the floor.

I hope it is pp as I just spent a grand on a Tex to find out!!

 

OK, how about when in BG? That must have crossed your mind!!

 

Probably, well maybe, but not much, will I be beating on it there either.

Heck, most interested people just want to hear it idle. That it will probably do a lot of next week.

I'm not drag racing it there, with this issue, there's no point. And other than maybe a spirited ride or two and some normal street commutes, it really won't get driven too extensively while I'm there.

I have no fears of driving to and from, and the around town stuff, but I ain't pushing it to the limits as much as I can control myself, which sometimes is easier said than done.

 

I had the exact same issue with the sticky clutch pedal and my original clutch never slipped. If I babied the car, the pedal never stuck. I did flush the fluids out every week and bled the clutch every month but it did not help me. I finally got sick of it and replaced my clutch with another POS LS6 clutch and all new hydraulics and my car ran fine without any problems full out WOT runs for 6 months and then it developed a new thing. I dont get the sticky clutch pedal anymore. Instead, WOT runs lead to SHIFTER ITSELF GETTING STUCK! My shifter wont come out of the gear for 30 seconds! I have to let the car coast and pump my pedal 10 times before my shifter comes out of the gear.

I bleed my clutch every month (I have LAPD remote bleeder) and my fluid is always crystal clear. I have a brand new Textralia ready to go along with all new hydraulics and this time I will wrap the lines (even the remote bleeder) with Thermotec. Is there anything wrong with my transmission or its the pressure plate/flywheel/heat again?!?!

 

The fluid is instantly black up top. If its instanly black it should be instanly hot?

 

Prestone DOT4 Synthetic won't change to black unless it's seriously contaminated.

Thumbnail-1 shows fluid from my LS7 reservoir at the point the clutch pedal just started to get lazy (1200 mile trip with a lot of 2-3 and 3-4 high-rpm shifts). Fresh fluid is nearly clear. Here it is a medium amber. It is degraded by contaminants.

Thumbnail-2 shows the same fluid hours later with the corruption precipitating out in the form of globules dissimilar to clean clutch fluid. Note the fluid itself is a lighter color with the contaminants separated.

Took six changes to bring the fluid to clean and clear again. And return the pedal to normal behavior. That included setting the record for a stock/stock tire C6Z quarter-mile, which involved 7K shifts and multiple passes, without incident.

If your fluid is black. It's boiling point is seriously compromised.

Ranger

 

Can you say for sure that the clutch never slipped? Every time you shift, there is some slippage.
I suspect that at high power on a factory clutch, there can be some "creep" that's not noticeable, but enough to generate heat. I can occasionally do long hard third or fourth gear pulls and get a funny pedal even without any shifts.

That's more like the problem I experience. The clutch won't disengage.

One thing that might compromise the effectiveness of changing fluid:
Does the new fluid come from a fairly fresh, tightly sealed container? Are you minimizing the amount of time the fluid is exposed to air when changing, especially in humid weather?
Common wisdom with brakes is to open a fresh container every time because the stuff absorbs water like crazy. Once the aluminum foil seal is broken on the container, there's just a cardboard gasket remaining in the cap.

I've worked quite a bit with anhydrous alcohol solvents, and it's almost impossible to keep them water free. Every time a container is opened, some air containing moisture gets in and the moisture is absorbed by the alcohol.

Brake fluid is alcohol based, except for DOT 5.

From the Valvoline web site:
"Most brake fluid is hydroscopic: It absorbs water. On the positive side, any moisture that enters the system—through condensation, through rubber parts such as seals and hoses or through an unsealed bottle of brake fluid—is dispersed throughout the fluid. That way, chances of localized corrosion and fluid freezing are minimized. On the other hand, absorbed moisture lowers the fluid's boiling point, raises its freezing point and degrades its anti-corrosion additives. As little as 3% moisture can decrease fluid's performance by 30% and also negate its anti-corrosives."

 

Change the clutch out and put a bleeder line in like LAPD sells. I bought the Centerforce DF clutch for like $350 and the SLP flywheel. I bleed the clutch before I go to the road course and never have any issues. My fluid still turns a darker color pretty quick, I think it's the rubber in the master. Use a high grade brake fluid like Motul 600 or Wilwood.

 

Do you have an opinion on why the brake fluid in the brake hydraulics changes color, e.g. gets very dark in a single HPDE?

Ranger

 

My brake fluid in the brake system doesn’t get discolored as fast as the clutch (brake) fluid. I’ll bleed my brakes, full flush (2 bottles of Motul) before an event and then I’ll bleed a little out after the first day. About a half bottle, just enough to get the burnt fluid out of the calipers. I’ll drive on the street with it like that till the next driving event and do the same ritual.

 

Thanks for the elaboration.

Please say what causes "...the burnt fluid out of the calipers." Bear with me. From your term "burnt" I assume you are indicating that heat at the caliper is transferred to the brake fluid and causes it to degrade. Is that correct?

Is the color of that "burnt" fluid different from the color of the brake fluid found at the brake master cylinder reservoir?

Ranger

 

I’m not claiming to be an expert in any way here. Everything is my opinion only.

Yes the heat transfer at the calipers will be quite severe after a day on the track (4x25 min sessions). If you bleed a little off after the first day you will be getting rid of the most adverse effected fluid. The fluid in the master and much of the lines is fine, only the fluid at the calipers was really effected by heat. After several weeks of driving without bleeding, this fluid would eventually cycle through the entire system. When I say burnt I mean it boiled or came close to boiling. Moisture I’m sure has a roll in the discoloring of the fluid. Any time you open a bottle of brake fluid it’s life span is severely shortened. I’ll use the older stuff in the clutch because it doesn’t get nearly as hot as the brakes. Moisture is why I bleed the brakes no more than a few days before a track event. That’s why brake fluid has a “dry” and a “wet” boiling point. New = dry and wet = old fluid.

 

I appreciate your patience in replying, thanks.

Have you ever run a day at the track without first bleeding the brakes?
If so, what happened to brake performance, and if not, why not?

Many thanks,

Ranger

 

No I have always bled them. I would think they would start to fade later in the sessions.

 

Thanks, for the replies.

I feel the same way about my clutch, because aggressive shifting and launches brings a similar load to the clutch fluid as a your track days do to the brakes. Fluid is the same; heat transfer agent is very similar. Load is similar. So I'd expect the adverse affects to be similar. And the change in fluid color is the tell.

Road racers know to bleed the brakes as a preventative measure. Owners who use their clutches aggressively ought to be doing the same. Those that do, don't get pedal woes.

Ranger

 

Ranger: I don't believe you can say with 100% assurance that flushing fluid will cure all clutch ills. I tried your cure along with insulating the hydraulics and my situation got worse, never better. I got tired of wondering if I could shift to the next gear. For the record, my car is not raced, drag raced, powershifted. It just reached the point where I could no longer shift into 4th after reving to 6500 and higher.

 

Me too. Bled, flushed, insulated....nothing worked. Replaced clutch with non oem, problem solved.
The parts that get hot are pressure plate, disc and flywheel. The pressure plate has way less mass then the flywheel and sees more heat ,and spring tensioned fingers lose their temper after some hard launches or lots of high speed shifts. Thats why one day all of a sudden, it sticks. Because the springs have lost their temper and never get it back. The first day my car did this I immediately went home and bled and flushed the system.........sorry, but it didnt work.
Yes shifting hard generates some heat, but not nearly as much as a hard clutch slipping launch (riding the clutch).
But I cant believe that the small amount of heat from shifting at high rpms will travel through the pressure plate and its fingers (have you seen the small contact area of PP fingers to the throwout bearing?) and go through the bearing and into the slave cylinder and boil the brake fluid........................all in 3 shifts? NFW
And im not just spewing usless info about clutches. Im not a pharmacist or IT guy (no offense) , but I have been an ASE master tech since '90. First 5 years I worked for a trasmission shop, so I know a little more than your average person about cars or transmissions.
But I do like to hear all the angles, because I love to learn new things.
I wish we could finally find the real slim shady on this problem.

 

Ya, no way I generated enough heat in one high speed run with easy shifts to boild the fluild NO WAY. It has to be something else. I'm pretty comfy with the PP being the issue, makes much more sense than the boiled fluid. The particulated in the fluid are not caused by heat, again, no way. The must be backwash with fluid being forced the wrong way past the seals. This fluid is not burnt, it is contaminated. Burnt stinks, I'd smell burnt clutch and I havnt smelt that since the track when it got smoked the first and only time. I'd like to find slim shady on this one too.

Has anyone besides Ranger had satisfaction with the clutch bleeding procedure he has outlined?

-Ken

 

My logic thinks that if the fluid did boil and you generated air in the system, then you would get a high spongy pedal that would be putting pressure on the throwout bearing/pressure plate WITHOUT your foot on the pedal at all. Instead the pedal is on the floor. I dunno
All I know is I could not handle having a nice fast sports car and not be able to shift it like it was meant to be driven. So I just dropped the coin and did the clutch after not being able to fix it any other way. Your results may vary
After we find slim, we are gonna need a

 

Hundreds of folks have.

This issue is very much like Torque Management. Those that believe, believe. Those that don't, continue to suffer.

It's certainly the case that those who sell clutches and install clutches seldom get behind a solution that involves owner self-help and eliminates lucrative revenue.

I deal with owners on the issue every week via PM and email. The success rate is close to 100%. Those that fail at the protocol I advocate are generally
(1) procedure-challenged folks lacking the discipline or motivation to follow a four-step process that take less than an hour.
(2) very high-HP cars with stock clutches.

I've also attended track rentals with a lot of 10-sec cars and when clutch pedal issue arise, heard one famous shop tell the sufferers to bleed the clutch. Good to remember that at least a few shops aren't reticent.

Ranger