Clutch pedal behaving strangely - lightness

[spinnaker]

So on with the next new query...

997.1 C2S manual

On Friday I took the car out for a drive and the clutch felt odd. I felt the usual amount of push back from the pedal but then if changing gear or putting into neutral it felt lighter the second time. Felt the same this morning too.

So in short:
- Push the pedal to change into gear at lights and the pedal pushes back with the same amount of force
-Push it a second time to change gear and it comes back lighter and slower
- If I leave is a few more seconds between pushes it seems to come back as strong as it did the first time.

Slightly unnerving as I now feel like at some point the pedal just isn't going to allow me to change in/out of gear in the middle of traffic or something!

The slave cylinder was replaced last year by the previous owner. Anything I should be checking? I figured I should check the clutch/brake fluid but I azm struggling to find the filler cap/reservoir in the frunk. #totalnoob

 

[JonnieD]

So on with the next new query...

997.1 C2S manual

On Friday I took the car out for a drive and the clutch felt odd. I felt the usual amount of push back from the pedal but then if changing gear or putting into neutral it felt lighter the second time. Felt the same this morning too.

So in short:
- Push the pedal to change into gear at lights and the pedal pushes back with the same amount of force
-Push it a second time to change gear and it comes back lighter and slower
- If I leave is a few more seconds between pushes it seems to come back as strong as it did the first time.

Slightly unnerving as I now feel like at some point the pedal just isn't going to allow me to change in/out of gear in the middle of traffic or something!

The slave cylinder was replaced last year by the previous owner. Anything I should be checking? I figured I should check the clutch/brake fluid but I azm struggling to find the filler cap/reservoir in the frunk. #totalnoob

I would have thought with those symptoms the problem is master or slave cylinder related. So checking the reservoir would be the first thing to do. Its in the front on the passenger side, close to the windscreen, there's a cover there over the cylinder / reservoir.

If the slave cylinder has been replaced, it could be a simple case of getting the system bled again in case there was some air trapped in there.

 

[spinnaker]

Awesome, good suggestions there. Many thanks, I'll check the reservoir in the daylight and look for any drips, etc.

Drove it again a bit earlier and it is a weird sensation. I'd say that the second push is about half the effort of the first and the pedal return is the same but if I leave for a sec then it feels like normal again.

I haven't driven the car much since Tuesday last week other than a couple of short trips when I have seen this. I did get the oil changed last week, also the gearbox oil and a new drive belt but I can't see those affecting anything in this area. Then the indie did go round and replace some a handful of pipe clips underneath the engine with jubilee clips. Should I be looking anywhere for drips of brake/clutch fluid?

 

[chowgar]

I was experiencing the same type of symptoms and shockingly after quite some time, I discovered my car mat was getting caught on the clutch pedal. Sometimes the simplest thing can lead you to look for a great fault!

 

[spinnaker]

I would love for that to be the case chowgar!

So I checked the reservoir today and it is happily in the middle of the min and max lines. There was no sign of residue under the reservoir. So that is a positive thing I guess?

I did get the gearbox oil changed last week, I presume there is no way that the clutch would feel softer because the gearbox is working more smoothly. Still wouldn't account for why it feels as it usually does for the first squeeze but not the second one and reverts back if just left for a few seconds.

 

[Alex]

Could be your clutch assist spring sticking. Clutch feels much heavier if the spring gets stuck in itscompressed position. Just a thought.

 

[spinnaker]

The harder feel of the pedal is how it has been since I bought it, just odd that it is hard (*cough*) most of the time and then momentarily light before returning to normal. It has me thinking it is going to fail totally every time I stop at lights/junctions/traffic at the moment.

I'll see what the indie says next week. I'm thinking I might get the clutch properly bled when there.

 

[spinnaker]

The clutch was changed 18k miles ago during the rebuild and the slave cylinder was done last year. Car has just ticked over to 55k miles so in theory the clutch should be in good shape.

 

[remarklima]

When the pedal is light, does the clutch still work as expected?

It sounds like the master or slave cylinder seal is broken or "flips" over so doesn't let the fluid return when going back - like sucking a straw that's collapsed. Or the spring has failed?

If the clutch operation is OK, and not crunching gears, then it'll be either of those I'd think.

There's a good image here:
https://generaltransmissionreno.com/clutch-slave-cylinder-symptoms/

Not sure if the 911 has the same setup tho, but would assume so?

 

[spinnaker]

Yes, I think is the answer to that. It hasn't let me down yet. I am usually driving when I feel this so I am usually just relieved that I am not blocking an arterial city road with a dead clutch! There is no horrible grinding and not more difficult to get the car into gear than any other time. I probably get the car up to temp and then take a drive on a quiet road and do some repeated gear changes up and down.

I need to take a look to see if I can spot anything with the spring too I guess. I have read that there is usually a noise when the spring has broken and I am not hearing anything unusual.

That could be a good shout. I'd suspect that it would be the master cylinder most likely if the slave was changed a year ago.

Thanks!

 

[spinnaker]

Quick update on this one for closure. I got the clutch checked out and test driven by my local indie and he seemed to think it felt okay. He did some checks and agreed that there was no leakage or obvious issues. I have been driving the car on short trips and a longer trip and it has been running normally. I'm still a bit hyper aware when driving out of fear of it failing in the middle of some arterial junction in my city but so far no issues. It is bothering me a lot less now that it continues to work fine. Ultimately I guess it is just two pump cylinders and a tube at the end of the day. There is only so much that can go wrong with that!

 

[spinnaker]

Hi all, so this issue is back albeit different. Having adjusted to the different pedal feel above (i.e. first clutch push is normal and then a much lighter and slower return) it has altered again. Now the pedal is light all the time and slower to return.

The pedal takes minimal foot effort to push until the last couple of inches of movement and feels the same on release. Releasing the clutch and going into gear happens in the first 2 inches of travel and then is soft for the remaining 5-6 back to normal position. So far there is no graunching of gears or difficulty getting in or out of gears.

The slave cylinder was changed by the previous owner last year. Looking at the master I can't see any fluid leakage and the level of fluid doesn't seem to change in the reservoir.

Any ideas?

 

[chowgar]

I'm having a similar issue, where from a cold start my clutch is sticking on the return travel, but it goes back to normal after driving for a while. I'm taking mine to the garage soon and I suspect there is air trapped in the system, so a clutch bleed via the slave cylinder might do the trick. My Indy reckons the clutch booster spring can't cause this type of issue.

I too have no fluid leaks.

 

[spinnaker]

Thanks for this @chowgar, that is really helpful.

This does sound familiar. A clutch bleed might be a decent quick fix and would give some time to figure out how air potentially might be getting in to the system.

I'm contacting a couple of local places to see if/when they might be able to do this and have a look at the clutch pipework and cylinders end to end.

 

[spinnaker]

Quick update on this one to (hopefully) close it off.

Yesterday I had the clutch master cylinder replaced and the clutch bled. As of now it feels much better and I haven't seen the inconsistency in pedal feel that I have been feeling for months. If this changes I'll update here again. Fingers crossed!