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Discussion Starter · #1 ·
Hi folks,

718 CS manual here.

Tonight, as I was on a spirited drive, I pulled away from traffic lights pretty aggressively a couple of times. At the last light, all of a sudden, the clutch started acting up: it would not come up at first, and when it did, it kind of stopped halfway, then came back to the top. Also, it was very difficult to select a gear, some more difficult than others.

When I pulled over and had the engine off, the gear lever felt like normal again, but with the engine running again it had the same issues again. The clutch pedal still feels like it's catching a bit halfway through the stroke.

Any insight as to what the cause is of this? Thanks in advance for any insights you could provide!
 

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sounds like you boiled off the fluid in the slave cylinder. some systems are self bleeding. not sure if ours is or isn't. usually it's shared with the brake fluid. I would check that the brake fluid isn't low.
 

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Discussion Starter · #3 ·
sounds like you boiled off the fluid in the slave cylinder. some systems are self bleeding. not sure if ours is or isn't. usually it's shared with the brake fluid. I would check that the brake fluid isn't low.
Thanks for the quick response!

I checked the brake fluid, it's right at maximum. I tried the clutch pedal again now that the car has cooled down a bit, but it still catches coming up before it completely comes back. I pumped it a bunch of times, but no change. Also pumped the brakes, but no effect. There is no liquid leaking anywhere.
 

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Discussion Starter · #5 ·
Update: after some more use and pedal pumping, the gears are back to engaging normally. Pedal movement is back to normal, with the difference that it is heavier than before. What could cause that?
 

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Update: after some more use and pedal pumping, the gears are back to engaging normally. Pedal movement is back to normal, with the difference that it is heavier than before. What could cause that?
The air in the line worked it's way up into the reservoir. Your gears are engaging normally now because your clutch is fully opening. The pedal feels heavier because pushing the pressure plate all the way open takes more force than opening it part way and compressing the air in the line.
 

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Discussion Starter · #7 ·
Quick update: clutch feels completely normal again, without having anything else done to it. Phew!
 

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I'm pretty sure it's self-bleeding. If it hadn't bled then the pedal wouldn't have returned to normal.
It's a lower priority item now, but in the next service I will be asking them to check and bleed, together with putting racing brake fluid in the system. Is it still combined like it was on the older models?
 

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sounds like you boiled off the fluid in the slave cylinder. some systems are self bleeding. not sure if ours is or isn't. usually it's shared with the brake fluid. I would check that the brake fluid isn't low.
Good call, Mike. I would support that idea.

How old is the clutch fluid? Is the slave cylinder in a place where engine heat can easily affect it? I haven't looked. On the Gen 1 Caymans, the power steering fluid reservoir was vulnerable to engine heat. Maybe this slave cylinder is becoming that sort of weak point?

Good idea to make sure and specify that the clutch fluid needs to be bled out and changed along with the brake fluid at service time. I've often neglected this working on my own cars. Never really had a problem with boiling clutch fluid, but with this mid-engine car, could it be??? Do we need heat shields? A fan?

BTW... OP, to enjoy a sports car it is not necessary to race off every stop light. Every time you do it, it tears the car up a little bit...and they aren't cheap to fix!. Hit the go-pedal hard, but only.... AFTER the oil temp is up to about 180 and when your left foot is OFF the clutch.

...Remember that all auto journalists are driving someone else's car.

Anytime you are slipping the clutch, you are wearing the clutch lining. When you slip the clutch at high RPMs, you wear it out fast. You need only about 1000 RPMs to smoothly engage the clutch...not more, but 1500 is OK, so long as you're not doing that repeatedly, uphill, in bumper-to-bumper for an hour etc.

When clutch is all the way in, or all the way out, no wear.

Want your clutch to last, like, for-ever? Drive like ME. I always start off at low revs, get the clutch OUT, then accelerate, sometimes hard, but always AFTER the clutch is fully out. Endurance racers know this sort of stuff. Think about the way the car actually works and drive accordingly.

Porsche could put a mondo-sized clutch on these cars and make them drag racers, but they wouldn't be a nice to drive and it would add weight and pedal effort etc.

I have a couple of techniques for avoiding clutch problems when I get stuck in traffic:

1. Leave as much interval as you dare...too much and someone fills the gap, but there is usually a place where you can keep pace with traffic, defend your lane and still leave some room. Find that happy place. When traffic slows, let your interval shrink as the engine braking slows you...no need for the brakes, many times, or the clutch...if you time it well, traffic will start to move again before you tag the car in front. This can be a fun game.
2. Use a gear lower than you need to and use engine braking...clutch still out fully. These cars will creep along at a fairly low pace in 1st gear smoothly at idle or a little above. Keeps airflow going and you aren't constantly slipping the clutch.
3. Hit the "long ball". Don't try to capitalize on every opening in traffic. Choose your battles. If you look beyond the immediate neighbor, analyzing the traffic situation gets to be second nature.

I actually enjoy a nice drive to the city in traffic...but it takes a little discipline to resist the racer instinct in slow traffic. I only "go for it" if I can see that my lane is really slower than the rest of traffic and that there is significant gain to my lane-change...and I won't be discourteous to other drivers.

There is a satisfaction I get from a well-driven trip into/out of the city in my manual Cayman. Not melting the car down is one of the goals, for sure.

:alien:
 

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I'm pretty sure it's self-bleeding. If it hadn't bled then the pedal wouldn't have returned to normal.
Not true. There's no such thing as "self-bleeding". If you boil moisture in the fluid, you create gas bubbles in the line and the clutch pedal won't push on the clutch...exactly like brake failure on race tracks with old brake fluid. When the car cools down, the water vapor (steam) in the lines, condenses back into water. Now the clutch (or brakes) work normally again. This is why people go for years without changing brake fluid with no apparent affect. If these same people try a track day and ignore the warnings to always have FRESH fluid in the car during track days, they get a big surprise at Turn 1 (end of the main straight).

I saw it with a Dodge Viper several years ago. The guy went straight off the main straight....had lost all braking. He was a Sprint-Car racer. They never use their brakes! He didn't know it was important.

This was an open track session. They give you an email about car prep, but not much real enforcement. Thankfully, this was Putnam Park. The best track on earth to go off the main straight!...nothing but grass for half a mile. No damage to the Viper except for him having to pull weeds out of his suspension when he got home.

:alien:
 
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It's a lower priority item now, but in the next service I will be asking them to check and bleed, together with putting racing brake fluid in the system. Is it still combined like it was on the older models?
They should CHANGE the clutch and brake fluid. Whatever is in there is boiling too easily. This problem will come back if you get the car hot again unless you change the fluid.

:alien:
 
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