Technical Clutch pedal jerky / sticks down

[pgainf]

Greetings!

I did have this problem until a few days ago.
The brake fluid was 2 years old or less but the car has been parked most of that time.

When I made a cold start the clutch would stick down to floor and I would have to pull it up with my foot.
Usually it would behave like this for the first 3 minutes and then it would work well the rest of the day.

Saw the 'Eric the car guy' video on how to change the brake fluid and bleed the system, and I changed it.
Problem fixed.
Now the clutch never sticks down or comes up slowly.
This made me realize how important is to change the brake fluid when the clutch system is hydraulic.

My regards

ps. My Fiat is a Stilo MW 1.9 JTD 2003.

Does this happen when it's very cold and the car has been left for several hours? Mine does exactly the same, and once warm it's fine.

 

[Sweetsixteen]

It is also possible that there is internal bleeding within the clutch hydraulics. Not so likely nowadays, but a long shot.

This is a 'closed' system, and if contamination has affected the fluid, the master cylinder (or slave cylinder more rarely) can allow fluid to seep past it's seals from one side to t'other when the pedal is depressed. The spring action will allow the pedal to eventually return, without any leaks showing up, or drop in fluid levels. If this is so, the pedal action will feel 'gritty' rather than smooth.

How to tell? Difficult, but by holding the pedal to the floor with gear engaged, sometimes the clutch will begin to bite after a moment or two. Not always a foolproof test. Just a thought - remembering times of long ago when you could buy master or slave cylinder kits in Halfords for this very reason.

Sweetsixteen.

 

[varesecrazy]

This is a 'closed' system, and if contamination has affected the fluid, the master cylinder (or slave cylinder more rarely) can allow fluid to seep past it's seals from one side to t'other when the pedal is depressed. The spring action will allow the pedal to eventually return, without any leaks showing up, or drop in fluid levels. If this is so, the pedal action will feel 'gritty' rather than smooth.


Sweetsixteen.

the slave is the lowest point..so any crud from inside the lines will naturally collect there

 

[Sweetsixteen]

the slave is the lowest point..so any crud from inside the lines will naturally collect there

Thanks for the observation. Good point.

One reason why - and I'm talking of moons ago when I tinkered with cars of a bygone age - the master cylinder often gave trouble even though higher up in the system, was that water or other contaminants entered through the reservoir, then corroded or softened the rubber seals right next to its point of entry - the master cylinder.

Slave cylinders got hit too, of course, but the height of the cylinders in the closed system did not seem to be the main determining factor.

- Sight easier to fix a hydraulic cylinder than to mess with the clutch! That was before the crazy fashion of burying slave cylinders inside the bell housing! And they call it progress.

Sweetsixteen.

 

[Prontissimo]

I have 'woken up' this thread as I too am having similar issues. When the car is cold, all is well, but after driving for a while, especially in heavy traffic, the clutch pedal begins to 'creak' and becomes very stiff to use. On the odd occasion, the problem becomes so bad that the pedal goes to the floor and stays there. Once out of traffic (so I guess under-bonnet temperature drops) it will free up again and all is well again.

The clutch fluid was pretty horrible, with crystalline deposits as described in other threads (hadn't been changed in 8 years...). I've cleaned the resevoir, replaced fluid and bled the system (several times) with Gunson's Easibleed. It is better, but still becomes stiff and creaky when hot, so I don't seem to have cured the underlying problem.

So, I suspect I need to replace the master cylinder... or the slave...? How best to tell which, and what's more likely to be the problem? I guess the master cylinder as that's where the creaks come from. Fair assumption??

(Should add, clutch and release bearing where replaced fairly recently, so that shouldn't be the issue)

In passing, what's the purpose of the black cable tie round the slave cylinder, which has a piece of white cable tie tucked under it?? The new part shown in the photo here also has this 'pointless' tie... http://www.shop4parts.co.uk/?name=store&op=details&ProdId=3254&sku=7839 . (press 'click to enlarge' to see the part photo larger).I ask, because the white piece of cable tie has dropped out... surely that can't be the problem, can it?

I have an 05 1.3 remapped multi jet Sporting with 56k miles. I'd noticed intermittent clutch slip during the last year of driving but recently it had been driving fine.....then things changed big time one day....plenty of clutch slip. I bit the bullet and booked it in for a new clutch but when I got it back it still slipped and engaging forward and reverse gears was crunchy. It was clear to me , because of the non gradual (sudden) failure that something mechanical rather than clutch plate wear , was the cause. I had the clutch slave cylinder replaced and all is now fine. Mechanics are awful at changing hydraulic fluid which should be done every two years.....on brakes AND hydraulic clutches! Most of these clutch faults are on older cars which almost certainly have NEVER had their clutch fluid changed. That allows moisture in the fluid to corrode components in the Master and Slave cylinders which makes their actions notchy or sticky. That causes the clutch to not fully disengage drive or to allow the clutch not to fully engage. The former means notchy gear engagement and the latter ......a slipping clutch. My car is plenty quick after the remap and I'd noticed before the recent clutch failure, smoke coming from the back of the car on a longish blast at 100mph!!! I'd thought it was oil but the sump level never dropped a millimetre. My clutch driven plate was shot at 56k miles.....why? I reckon the smoke was from a slightly slipping clutch at speed ......maybe the engine revs were 100 rpm disengaged from the road wheels......a slightly slipping clutch which over time wore out the driven plate. So....before you replace the clutch check your hydraulic fluid is new and that both your master cylinder and slave cylinder are operating freely! You could save yourself £300!!!! They're fabulous little cars .....and very quick with a software remap and EGR blanked off. But modify/check the air cleaner is set up right.....see my other thread. And also change the oil at 10k miles max. I use Fuchs GT1 longlife 5-30w but change every 6k miles.....it only holds 2 litres of the stuff!!! That way you'll protect the camchain .

 

[davehob]

Hi jrkitching
I know it's been a while since this post ended, but I need to replace the white nylon bush in your pics.
Do you have any idea how to go about this?
Thanks in advance davehob.

 

[DaveMcT]

Hi jrkitching
I know it's been a while since this post ended, but I need to replace the white nylon bush in your pics.
Do you have any idea how to go about this?
Thanks in advance davehob.

JR will be along soon, but I might be able to help.

My clutch was replaced last year, because it was not releasing properly and drive was delayed by about a second after lifting the pedal making it almost impossible to drive smoothly. It turned out the friction plate was actually still serviceable, but the pressure plate was knotchy (likely to be causing the delayed action).
The second problem was the hydraulics. The clutch worked better after bleeding the fluid but would soon be failing again and causing gear selection issues. The cause is air getting past the master cylinder seals. A severely worn master cylinder will eventually drip fluid onto the carpet inside the car.
So I'm basically saying that if the clutch has worn out from normal use, the hydraulics (master cylinder, pipe and slave cylinder) will also be worn out and should be changed.

You can test the hydraulics by pumping the pedal. It's not a fix but if the gears shift a little easier after two or three quick pumps its likely you need new hydraulics. There is no repair kit available.

If there is any brake fluid on the carpet, you need a new master cylinder.

 

[JonboyPandamonium]

I’ve noticed a lot of different theories on this thread, but can anybody recommend a prioritised checklist?
My 06 4x4 has the symptoms as described and the clutch pedal stuck to the floor for the first time last week.

Stiff clutch
Squeaky clutch
Intermittent juddering when accelerating of in 1st, especially when cold.

I don’t know if it’s a coincidence but I did take the kids up a couple of green lanes in it a few days prior, after the heavy rain, and had water over the bonnet!

Thanks.

 

[DaveMcT]

I’ve noticed a lot of different theories on this thread, but can anybody recommend a prioritised checklist?
My 06 4x4 has the symptoms as described and the clutch pedal stuck to the floor for the first time last week.

Stiff clutch
Squeaky clutch
Intermittent juddering when accelerating of in 1st, especially when cold.

I don’t know if it’s a coincidence but I did take the kids up a couple of green lanes in it a few days prior, after the heavy rain, and had water over the bonnet!

Thanks.

There are two areas to consider. The clutch itself and the release system (hydraulic in a RHD car).

Clutch -
Juddering and squeaking suggest the clutch is getting close to being worn out. The spring plate fingers get worn and when the friction plate becomes worn too thin the mechanism cannot work smoothly. You might also notice a lag when lifting the pedal and the pedal may feel heavy and even bouncy rather than if its moving the clutch.

Hydraulics -
Pedal does not release the clutch properly, pedal does not return to the top after use sometimes the clutch is lagging behind pedal action.

Your case sounds like the clutch is worn out, but if the hydraulics are the same age, they are likely to also be at end of life. I suggest you confirm the clutch by changing the hydraulics. If that solves your problem then great. If not, then you'll need to change the clutch. This is not false economy because new hydraulics will be needed with the new clutch.

It's already been discussed that changing the slave alone is pointless. This is because the slave will leak fluid before it sucks in air. A worn master however will suck air causing the soggy pedal etc. Change the whole hydraulic system and be done with it.

 

[JonboyPandamonium]

There are two areas to consider. The clutch itself and the release system (hydraulic in a RHD car).

Clutch -
Juddering and squeaking suggest the clutch is getting close to being worn out. The spring plate fingers get worn and when the friction plate becomes worn too thin the mechanism cannot work smoothly. You might also notice a lag when lifting the pedal and the pedal may feel heavy and even bouncy rather than if its moving the clutch.

Hydraulics -
Pedal does not release the clutch properly, pedal does not return to the top after use sometimes the clutch is lagging behind pedal action.

Your case sounds like the clutch is worn out, but if the hydraulics are the same age, they are likely to also be at end of life. I suggest you confirm the clutch by changing the hydraulics. If that solves your problem then great. If not, then you'll need to change the clutch. This is not false economy because new hydraulics will be needed with the new clutch.

It's already been discussed that changing the slave alone is pointless. This is because the slave will leak fluid before it sucks in air. A worn master however will suck air causing the soggy pedal etc. Change the whole hydraulic system and be done with it.

Thanks DaveMcT, that is really great information. Maybe it was just wishful thinking, believing there would be a cheap fix!!!
Cars only done 50k though, I’m sure I’m not alone in thinking the clutch should have a longer life than that?

 

[DaveMcT]

Clutch life is very dependent on the driver and the type of use the car has had. Mechanically sympathetic driver doing mostly long journeys will see at least 100K on the clutch. Town driving with a person who holds the car on hills might see 50K or less.

First of all try bleeding the clutch hydraulics. You will need to remove the battery and support box to access the slave bleed screw. If that helps but the problems return you will need to replace the hydraulics. Its not worth doing a part job just change the lot - pipe-line and all.

If bleeding the clutch makes no difference to the symptoms, you will need a new clutch and would be wise to fit new hydraulics at the same time.