Mid Ohio Observations and Clutch issue

**SRT84X4** · #1 (**permalink**) 05-27-2007, 11:30 PM

Thursday the 24th, I made over 40 laps at Mid Ohio. My car has LSD, Bilstein coilovers, H&R sway bars, Mill-tek 100cell + complete system, Hawk HP Plus pads.

I left for the track with new Michelin 18" PS cup tires only to have a flat on the way....my buddies delivered my stock 19" wheels with OEM brigestones and on I went.

I have the swaybars set on the soft setting in the rear (two choices).

Shocks set on #2 all around. Camber -1.5 LF -1.8 Bolt slots lengthened. rear 2.0 (lowest available with the car lowered).

The track handling is awsome. When former F1 competitor Tommy Byrne drove me around in the CS for a few laps, he told the other instructors that it the best handling car that he had driven around MO.

After twelve laps, I pulled in to the pits for 15 minutes. When I get back in , I had no clutch. The pedal was on the floor. When it cooled off for another 10 minutes, I was back in the game, all working normally.

The problem continued to repeat itself after stops, never on the track. When I got back home, we realized that when we changed to Castrol SRF synthetic brake fluid, we bled the brakes, but not the clutch which feeds off of the brake reservoir, so the cluthch still had oem fluid in the line. The slave cylinder is on the top of the transmission where it is surrounded by heat shielding, and gets no air unless you are moving fast. When you stop, all of the heat collects up around the slave cylinder with no place to go. We bled the clutch and got a lot of bubbles out, then topped it of with the Castrol SRF. Hopefully this will solve the problem.

I was amazed at the performance of the stock tires. They stuck really well, and showed little wear after an amazing amount of abuse. If I hit the apex just right coming out of the keyhole, I would hit the rev limiter in 4th right as I lifted to brake for the right hander at the end of the back straight. I think that the stock tires might have enhanced my learning experience as the gave a lot of warning, and the high slip angle is very predictable.

Thanks to the post on the pedal adjustment, the stock position is attrocious for heel and toe shifting, and at a buck 30 + at the end of the back straight, you want to know that you will get it right

I noticed that others have had the clutch problem. Is there a fix other than what I have Done??

**alex@princeton** · #2 (**permalink**) 05-28-2007, 12:28 AM

you should have fixed it witht he clutch bleed it is a coommon mistake to forget about this when changing fluid. the 2 dont like to be mixed

douzzer · #3 (**permalink**) 05-28-2007, 07:27 AM

This thread got me wondering about ways to cool brake fluid. Apparently, earlier generation Cup cars have brake fluid recirculators. These banish boiling and hot spots, and (although this doesn't seem to be mentioned often) they will keep the calipers cooler, which means the pads and rotors will be marginally cooler too. Here's one example of an aftermarket race app part. The general complaint with recirculators is expense, but this thing is only $160, which in this neighborhood counts as free.

**SRT84X4** · #4 (**permalink**) 06-16-2007, 01:16 AM

Well, I just return from a DE track day at Putman park. You will see in the earlier chatter that i had an issue at Mid Ohio with the clutch going to the floor due to boiling the brake fluid. I thought that bleeding to make sure that I had no bubbles and had all Castrol SRF in the line would fix it, but after the second session today, I was back with the clutch pedal on the floor. I am going to have to try a more aggresive fix. perhaps an insulated line, and or a small cooling duct.

Surely more of you have had or will have this problem. Any more suggestions.

After warmup, nobody with a license plate every passed me

There were two site members that said they were coming. I saw a red CS parked, but no one else had a CS on the track?

mooty · #5 (**permalink**) 06-16-2007, 03:06 AM

Quote:

Originally Posted by SRT84X4

Well, I just return from a DE track day at Putman park. You will see in the earlier chatter that i had an issue at Mid Ohio with the clutch going to the floor due to boiling the brake fluid. I thought that bleeding to make sure that I had no bubbles and had all Castrol SRF in the line would fix it, but after the second session today, I was back with the clutch pedal on the floor. I am going to have to try a more aggresive fix. perhaps an insulated line, and or a small cooling duct.

Surely more of you have had or will have this problem. Any more suggestions.

After warmup, nobody with a license plate every passed me

There were two site members that said they were coming. I saw a red CS parked, but no one else had a CS on the track?

this is not due to boiled fluid.
i had it happen too. there's a TSB for it. the clutch / flywheel on lots of caymans weren't installed correctly. and pedal to the floor was a symptom of that . you can pull the pedal up then it will work for a while, then same thing happens again, right?

they will give you new flywheel and/or clutch. i had 3 caymans and two had that prob. both fixed under warranty.

**SRT84X4** · #6 (**permalink**) 06-16-2007, 09:05 PM

Mooty.

Thanks for the feedback, I hope that you are right. Mine is a january 2007 build and I thought that they had that problem straightened out by then. My problem only happens when the car is really hot. If I go drive at 50 MPH or so for 10 minutes, It goes away. Was that the case with your cars..........mine does start to work if I pull the clutch uo by hand, but only after the car has cooled down. Otherwiae it just goes back to the floor (only part way then though). Also now I notice that the shifter has a sort of creaky feel as if the lube has melted out at the rear or similar. I thought that maybe this was for the same reason, but if it is an install issue then they are not related.

Do you know what the install issue is? What didi they do wrong?

mooty · #7 (**permalink**) 06-17-2007, 05:09 AM

Quote:

Originally Posted by SRT84X4

Mooty.

Thanks for the feedback, I hope that you are right. Mine is a january 2007 build and I thought that they had that problem straightened out by then. My problem only happens when the car is really hot. If I go drive at 50 MPH or so for 10 minutes, It goes away. Was that the case with your cars..........mine does start to work if I pull the clutch uo by hand, but only after the car has cooled down. Otherwiae it just goes back to the floor (only part way then though). Also now I notice that the shifter has a sort of creaky feel as if the lube has melted out at the rear or similar. I thought that maybe this was for the same reason, but if it is an install issue then they are not related.

Do you know what the install issue is? What didi they do wrong?

my only occurred twice, both times i was on track, luckily it happened after the session is over as i pulled into my parking space in the paddock.

i pull the pedal up immediately and it functioned like it never had a prob (the engine was still hot when i pulled the pedal up).

the two episodes were about one months apart.

**SRT84X4** · #8 (**permalink**) 06-18-2007, 02:49 PM

Mooty,

Just as you stated, my clutch problem happened right after pullung into the pits and sitting for a few minutes. It only happened once on the track. I just assumed that the cats running at 1500F or so heat soaked the area around the slave cylinder when the airflow stopped, and boiled the fluid.

After they changed your clutch, did you ever have a repeat of the problem? I am trying to understand how a clutch or installation problem could cause the symptom. Did the dealer explain to you what was happening.

Thanks again for the feedback