Coagulated cluth fluid

[gtinmyblood]

Ok, I need a little wisdom and advice. I ran the track day at firebird west track last week with the rest of the Arizona guys. Had a BLAST! did about a 30 minute session and then another almost 45 minute session running hard. Toward the end of the second session I lost clutch pedal. The travel was maybe 30%. After I parked the car and it cooled I found that I was bumping 1st and second and couldn't for the life of me get into reverse. Ok so I burned the clutch I figured. Now we have the car apart and we find that indeed I heated the clutch up pretty good but even more suprising is that the clutch fluid in the master is jellied. Not sure whats up here. The track was damp that morning but I can't imagine I got water in the clutch! Have any of you heard of this?

 

[Neilda]

Could you have boiled (overheated) the clutch fluid? This can happen and some fit heatshields to protect the fluid from overheating.

I don't know what happens once boiled if it does turn to a jelly.

Here's a post from Kingman, it's from a thread a while back on this subject:

"On the Lotus, the hydraulic clutch line ran next to a radiator line front to back. As ‘ThatPhilBrettGuy’ described, the clutch line hose would expand as well as the fluid boiling, causing the clutch to fail (I broke a throwout bearing once trying to slam it into gear while traffic was coming at me). After several clutch plate replacements, master and slave cylinder replacements, and other 'guesses' by Lotus, a forum just like this one came up with the answer - a shielded clutch line that was also wire braided for further support against expansion."

Edit

......and yet more research! Apparently clutch fluid turns into a gel when exposed to air!

I'm not normally this attentive on technical posts - but I was curious.

"With age and exposure to air, brake fluid changes from a fluid, to a gel-like substance. Eventually, the gel changes into a crystal-like powder."

 

[gtinmyblood]

I certainly could have boiled the fluid. I know there have been some posts about overheating the fluid but I'd never heard of it going jelly. What fluid should I use? Are ther examples of heat shields that have been used? Is heat wrap in the lines enough? Trying to get my mind around it.

 

[Neilda]

I've just edited my previous post to suggest air contamination. Possible?

 

[gtinmyblood]

I guess anythings possible. Just seems really odd. I'll do some more checking and post results.

 

[Team Jeff]

Interesting, I had never heard of clutch fluid turning jellied. Isn't the clutch fluid also brake fluid?


Nathan, is your car at ADS in Chandler?

 

[Neilda]

Interesting, I had never heard of clutch fluid turning jellied. Isn't the clutch fluid also brake fluid?

I hadn't heard either - but it would seem that air contamination has this effect on brake fluid and it would be reasonable to assume clutch fluid too... Not sure on boiling and cooling, but definitely air.

 

[tmcphail]

Interesting, I had never heard of clutch fluid turning jellied. Isn't the clutch fluid also brake fluid?
QUOTE]

Yes. I use hi temp synthetic in my car. Pushing the car hard at the strip or track will cook the fluid big time.

 

[gtinmyblood]

Interesting, I had never heard of clutch fluid turning jellied. Isn't the clutch fluid also brake fluid?


Nathan, is your car at ADS in Chandler?

Yes my car is at ADS in Chandler. We are doing the same clutch set up as they did for Kurt Thompkins GT. I have been doing quite a bit of research on this. Here is what I have found:

The stock fluid is poor and will easily boil under any performance condition.
This is true for both clutch and brake fluids.
The location of the clutch fliud tube is too close to the exhaust even without an aftermarket header. Some level of heat shielding is a REALLY good idea even on a stock set up.

The following was provided to me by Doug at ADS...

BRAKE FLUID COMPARISON CHART
Brand Wet Boiling Point Dry Boiling Point
Castrol SRF 518°F 590°F
Motul RBF600 420°F 593°F
Wilwood EXP 600 417°F 626°F
AP-600 410°F 572°F
Brembo LCF 600 399°F 600°F
ATE-Super Blue 392°F 536°F
Valvoline 333°F 513°F
Castrol LMA 311°F 446°F
Ford HD 290°F 550°F
Wilwood 570 284°F 570°F
PFC-Z rated 284°F 550°F
AP-550 284°F 550°F

 

[Team Jeff]

Yes my car is at ADS in Chandler.

As I'm sure you already know, the guys at ADS are top notch. I've known John, Doug for years and can't say enough about them. :thumbsup

 

[Team Jeff]

The following was provided to me by Doug at ADS...

BRAKE FLUID COMPARISON CHART
Brand Wet Boiling Point Dry Boiling Point
Castrol SRF 518°F 590°F
Motul RBF600 420°F 593°F
Wilwood EXP 600 417°F 626°F
AP-600 410°F 572°F
Brembo LCF 600 399°F 600°F
ATE-Super Blue 392°F 536°F
Valvoline 333°F 513°F
Castrol LMA 311°F 446°F
Ford HD 290°F 550°F
Wilwood 570 284°F 570°F
PFC-Z rated 284°F 550°F
AP-550 284°F 550°F

So, is the fluid with the highest boiling point the best? What other considerations are there? Shelf life? Lubrication?

 

[Kingman]

Yes my car is at ..............The location of the clutch fliud tube is too close to the exhaust even without an aftermarket header. Some level of heat shielding is a REALLY good idea even on a stock set up...............

:willy

This sounds like a job for the usual suspects on this forum to come up with an elegant solution.....and they know who they are. :biggrin

 

[Derry]

FWIW, I had my car at Firebird West track last year for 3 solid days. When I was not in it someone else was. A bunch of us brought my GT, a Noble, Viper, ZO6, Roush stang, F40, F50, an Enzo and Porsche Carrara. We ran them pretty hard, more than one had no rotors at end of day 2 but I never had anything like this happen. I had DOT4 in the brake system that has a higher boiling point but not the clutch fluid. Also, there are trade offs, DOT 4 is much more hydroscopic (absorbs water) than DOT 3. So for infrequent driving or storage #3 would be better. Just my $.02. I can't figure what happened to you though. Any chance the level was low before it got toasted?

Derry

 

[gtinmyblood]

all fluids were checked the night before I ran. Either it boiled, or got water in it from a damp track day, or???