greg1234

Hi all.

My clutch creaks very loudly when the car is warm and I operate the pedal (at rest with the engine off). The pedal is also quite heavy and when the car is warm it gets less smooth in operation. I've been told that means I need a new clutch.

However trawling through the board there are a number of different clutch problems, and a number of different fixes. I've seen mention of bleeding, release bearings, slave and master cylinders and so on. The pedal is also quite heavy and when the car is warm it gets less smooth in operation.

If I just look at the symptoms - the loud creaking noise from the rear of the car and heavy pedal - what is the most likely problem I have right now? Which component is making that creaking noise?? And why would the entire clutch need to be replaced??

Many thanks for any advice.....

GeoT3

Greg, it sounds like its the clutch slave cylinder needing to be replaced. Its a common problem with the G50 trans. I cannot tell you why a slave cylinder is responsible for the noise - have not disected my old one yet, but it did solve my noisy clutch problem and hard pedal.

Adrian

Dear Greg,
This question was answered for you on another thread. First thing to do is get the system bled. Before opening things up and replacing perfectly serviceable components, bleed the clutch and get the air out. For George, did you have your system bled properly. A very hard pedal is often insufficient pressure in the line leading to the slave cylinder,
Ciao,
Adrian
911C4

greg1234

Hi Adrian.

Thanks for your info. The question was *not* answered clearly anywhere. I understand your advice is to bleed the system properly, since this eliminates a number of problems and (I agree completely with you on this) it makes no sense to replace components that are perfectly serviceable.

But something is making that loud creaking / squeaking noise, and I just wanted to know what people's experiences are in terms of what causes this. I had heard that it could be the release bearings, and George has suggested it could be the slave cylinder. You are suggesting it could be alleviated by bleeding.

The reason why I'm skeptical about bleeding being a fix is that it sounds to my (untrained) ear like it's some mechanical component grinding or rubbing or straining. It doesn't sound like the sort of thing that can be fixed by bleeding. I also don't understand how a sound like that can be caused by the slave cylinder.. but that's why I posted the question. I want to understand what is making that noise before I let anyone go ahead and start replacing things.

And when people say "it's the slave cylinder" - what exactly do they mean? What typically is the problem with the slave cylinder?

[I guess if you heard it you'd probably know instantly what it was. It's hard to describe hear - it's a mixture of creaking / squeaking / groaning every time the clutch pedal is depressed. But it's not there when the car is cold.]

Anyone else recognise the sound? If so what was it caused by?

greg1234

Just to explain why I don't just get it bled and see if the problem goes away -

I plan to go back to the dealer with a list of the more important problems that have been identified. At the moment the clutch is a possible serious issue. I only have 3 months from when I bought the car in which to go back with problems, so I need to decide which ones I am going to complain about, and what I am going to insist on them doing. The situation I want to avoid is where I go back to them, and they tighten a couple of things, stick some lube in somewhere, bleed the system and - hey presto - the problem goes away. Then it comes back 4 months later, and now it's outside the warranty period and I end up having to pay for a new clutch myself.

I hope that explains why I'm so keen to get everyone's opinions as to the most likely explanations for my symptoms...

greg1234

Just to explain why I don't just get it bled and see if the problem goes away -

I plan to go back to the dealer with a list of the more important problems that have been identified. At the moment the clutch is a possible serious issue. I only have 3 months from when I bought the car in which to go back with problems, so I need to decide which ones I am going to complain about, and what I am going to insist on them doing. The situation I want to avoid is where I go back to them, and they tighten a couple of things, stick some lube in somewhere, bleed the system and - hey presto - the problem goes away. Then it comes back 4 months later, and now it's outside the warranty period and I end up having to pay for a new clutch myself.

I hope that explains why I'm so keen to get everyone's opinions as to the most likely explanations for my symptoms...

GeoT3

Adrian, yes, the system was properly bled 2x. The noise went away after initial bleeding - alot of dark fluid came out. clutch worked like butter after first bled but noise and hard pedal came back after one drive. Replaced the slave cylinder and noise is gone and operation is smooth. this has been discussed many times on the 993 board. Replacing the slave cylinder was the only way to cure this. Don't ask me how or why. have not disected the faulty part yet - how can rubber seals make all this noise?

Adrian

Dear George,
The slave cylinder is the second thing you do. First thing is to bleed the system always. The reason is that you have to bleed the system when you change the slave cylinder. You will never know if it really was the slave cylinder or just the bleed which fixed the problem. Simply a cost issue. Why replace something unless you can prove it unserviceable. In your case you did it perfectly. A lot of people have 20/20 hindsight but I always advocate, start cheap and work towards expensive. From my early days of Porsche ownership I ended up with a basement of what we call at work, NFFs (No fault founds) units. Cannot sell them because they really never fail they were just the easiest for inexperienced mechanics to replace, and for me to pay for,
Ciao,
Adrian
911C4

Riccardo

I think I won't be of any help here, but I had a similar problem recently and thought I'd share my experience.

My clutch creaked if I pressed on the pedal when the car was cold and off. The noise would go once the car was warm/hot. Also, the pedal does not return fully, this happens more when the car is cold.

The system was bled as soon as I bought my car, after that is when the problems first caught my attention. The car already had, I think two years before, had clutch master and slave cylinders replaced, and one year before the whole clutch assembly changed.

I took it to JZ and they suggested replacing the master cylinder, which I did. System was bled again. I don't hear as much of a creak now, but the pedal is still iffy.

Who knows what on earth is the problem????

Bill Wagner

Greg:

I tend to agree with the previous poster. High pedal is frequently caused by something failing in the clutch assembly. The fact that it gets worse if the car is warmed up also implies it's clutch related (a binding throw out bearing, to be specific). If it is only a throw out bearing, which I think is a good possibility, unless the clutch for some reason is in good condition, it would be normal to replace the clutch disk as well...particularly when the cost of labor to re-install it later will be much more than the cost of the parts.

The only other thing I could think of is actual binding in the clutch pedal mechanism itself. It's certainly worth looking at FIRST because it's the cheapest thing you can do and it is a possiblility. Pedal noise will only occur in most cars if the pedal mechanism is being strained (which indicates a heavy load...like a failure in the clutch) or some type of binding. Slave and master cylinder release failures are usually exposed when pushing in the clutch pedal doesn't allow complete release of the clutch. If you put the car in first gear on a perfectly flat surface, push in the clutch, and the car starts to move and/or you have a hard time shifting into gears from a standstill, hydraulics are a good thing to suspect. Another symptom of hydraulic failure is a sticking pedal or a pedal that won't return "home" when released. Rarely do hydraulics contribute to a high pedal effort...possible but unlikely.

If I was in your position I would look at the clutch pedal binding first because it is without a doubt the cheapest fix. If that doesn't work, well then it's up to you...I really don't understand how bleeding the system would help unless the fluid has been in there for years and/or there's some reason to suspect the system has been contaminated. Brake fluid changes on these cars are not cheap.

My guess: Your clutch and/or throw out bearing are failing.

Hope this helps,

Bill Wagner

greg1234

Hi Bill.

Thanks for the info. You say that master and slave cylinder failures normally result in the clutch failing to take the car out of gear completely. Well my symptoms are that the clutch seems to operate fine - the clutch bites when the pedal is depressed around 1/6 of the way down it's entire travel, and there's no hanging or looseness at the top. However there is this loud creaking from the rear (worse, as I say, when the car is warm ie after town use) and the pedal feels "sproingy" once it's past the bite point (again it's worse after heavy town use). Once it's got creaky and sproingy, I can leave the car for half an hour, come back, and it's still creaky and sproingy.

But it does seem to operate properly in terms of taking the car out of gear.

Bill Wagner

I'm afraid I don't fully understand what the term "sproingy" means. If you mean spongy, like a car that needs it's brakes bled, then as Adrian said, you may well have a bleeding that needs to be done. I don't know if you have a "car stethoscope", but if you do, you might be able to get the car warmed up to the point it's noisy again, shut the car off, and the then use such a tool to try and isolate the source of the noise. I would put it on the slave cylinder itself, the bell housing body, and any other places the noise seems to be coming from. The car will need to be in the air to do this.

When the master and/or slave cylinders fail, the gaskets on the pistons usually allow fluid to seep past them. When you push the pedal in as the fluid seeps past the gasket, a portion of the fluid that should have been used to drive the clutch lever forward doesn't get applied to it. In this case, it would be equivalent to only pushing your pedal down about 1/2-3/4 of the way...hence the incomplete release of the clutch and creeping when in first or hard shifting (because the clutch never quite releases fully and it's dragging on the flywheel). In the more extreme case, some of the fluid that got behind the cylinders (most notably the slave clyinder) stays there and the pedal doesn't fully return when the foot is taken off the pedal. If your something in your hydraulics is JUST STARTING to go bad, then maybe the master or slave cylinder could cause the noise, but I sort of doubt it because the fluid also behaves as a lubricant.

Hope this helps,

Bill Wagner

greg1234

Hmm.

It's beginning to sound like the slave cylinder is not likely. I have showed it to two independent Porsche specialists - one thought it was something to do with a guide tube?? and the other thought it was something to do with needle bearings (?) or something like that. He's the one that reckoned it would need a new clutch.

Oh well - I'm taking it round to the dealer that sold it to me this afternoon so they can listen to the noise and make their first move...

greg1234

The saga continues -

I took the car back to the dealer yesterday and asked them to look at the creaky clutch and to check whether the front wishbones need replacing (I already knew that the RH wishbone bush has come away from the metal and needs replacing).

Their answer regarding the wishbone bush was 'Yes, it's "starting" to come away a little, but there's no more play than there is on the other side' - an anwer that left me feeling fairly unimpressed. I bet at speed when cornering hard the two *will* behave differently.

As far as the clutch goes, they confirmed that it creaks loudly (impossible to miss it really) and that the pedal feels notchy. Their answer here was "something's just dry", so they:

a) Spent some time squirting lubricant at various parts of the clutch from beneath the car (as I predicted!) - made no difference

b) Said that it's probably because the car was unused for so long and is now being used, so it might go away (!)

c) Said "Well, if it fails, we'll replace it" (!!)

d) Resisted all attempts to acknowledge any sort of obligation to cure the noise (or, more importantly, whatever problem is causing the noise)

So I will leave it for a few days, get an independent specialist to produce a report, and then go back and confront the guy who sold it to me.

At this stage I'm not hopeful, but I have to try.

Bill Wagner

Greg:

I'd really be interested in hearing what the report from the independent mechanic comes up with....I can add it to my database of 964 problems, symptoms, and cures

Thanks,

Bill Wagner