Technical Clutch pedal jerky / sticks down

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Technical Clutch pedal jerky / sticks down

penguin2727

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Hi,

I have an 04 plate 1.2 Eleganza, and have noticed the clutch pedal occasionally "sticks" to the floor and fails to return. Often just before it happens the clutch pedal becomes slightly juddery, moving in sort of half-inch steps rather than travelling smoothly. After a few times of the pedal sticking to the floor, all is fine for the next few weeks.

I thought initially it could be me being foolish and getting mats stuck under the pedal or in the mechanism, but I took them out to be sure and the problem still occurs. Lookign around people suggest it could be the master cylinder, but I've not noticed any leaks on the ground after the car's been parked. As it doesn't happen all the time I'm wondering if there's some dirt or water in the fluid which slowly works its way to a cylinder and causes hell before it moves on. Would it be worth draining the system and starting with new fluid? The car's in for an MOT soon so I can ask them to check it too, but I'd rather be able to give them a pointer or two to what might be wrong if people have experienced it before :)

Cheers!
 
It can do, but it has also happened in the middle ofa 200 mile drive when the car is certainly not cold!
 
I checked it when it first started happening, and the level was fine. Since then I have kept an eye on it and there hasn't been a drop in the level, which suggests it isn't leaking...
 
I looked at the clutch fluid as suggested by jrkitching (great posts by the way, thanks! :) ). There's no evidence of a deposit at the bottom, though the fluid does look ever so slightly cloudy/translucent. Perhaps water has found its way in through the breather hole in the top of the cap?

DynamicPanda, the car is regularly driven, and I would have thought that if the master cylinder was the problem then I'd see the issue all the time, rather than intermittently? But perhaps I'm wrong.

I also asked the garage to take a look when the MoT was done. Their suggestion is that it could be caused by a plastic arm on the back of the clutch pedal that has worn down over the years. Is this plausible?
 
I looked at the clutch fluid as suggested by jrkitching (great posts by the way, thanks! ). There's no evidence of a deposit at the bottom, though the fluid does look ever so slightly cloudy/translucent. Perhaps water has found its way in through the breather hole in the top of the cap?

Thank you. The breather hole by design lets air in & out of the reservoir. The moisture in that air can condense out inside the reservoir - it's particularly likely to happen when you get a combination of warm, humid days & cooler nights. The black diaphragm is supposed to stop this condensate from getting into the fluid, but over a period of years, some moisture gets past and the fluid becomes saturated.

Saturated fluid is bad news, because the water content can corrode the steel components in the hydraulic system. In the case of your brakes, it's doubly bad, because under extreme operating conditions, the water content can boil, drastically reducing braking performance.

That's why it's important to change the hydraulic fluid regularly - most have a service life of 2 years.

I'm guessing that yours may still be the original, in which case I'd recommend getting it flushed. I don't think it'll solve your current problem, but it will prevent further trouble developing later.

I also asked the garage to take a look when the MoT was done. Their suggestion is that it could be caused by a plastic arm on the back of the clutch pedal that has worn down over the years. Is this plausible?

Wear in the mechanical part of the clutch pedal is indeed a plausible cause of your difficulty. I'm not sure about the reference to 'a plastic arm on the back of the clutch pedal', but there is a white plastic (probably nylon) bush which locates & guides the return spring. If this became worn or damaged, it could indeed cause the kind of difficulties you've been having.

You can inspect it visually yourself if you don't mind doing some contortions. Look up into the driver's footwell (you'll probably need to lie on your back outside the car to do this, unless you've access to a lift), and locate the spring and bush. You need to get the viewing angle right, as the steering column shaft runs diagonally across in front of the mechanism & somewhat obstructs the part you want to look at. Now use hand pressure to press & release the clutch pedal, and see if you can see anything catching or obstructing the movement - if all is well, it should move quite smoothly, without any jerks, tight spots or hesitation. Look for anything unusual - it could be a bit of cabling that's fallen loose, a dislodged bit of trim - I've even found part of a ladies shoe in a similar place.

The photos attached show you what you're trying to see - the big spring & white bush are clearly visible in the middle. I've left them in high resolution so you can see them more clearly - just click twice to enlarge.

Hope this helps.
 

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Confused of Hartlepool here,

I like Penguin have this problem.

I like Penguin initially thought the mats were the culprit.

Then after taking the mats out and it happening again I checked the fluid level as prescribed by M E P and everything was OK (i.e fluid to the correct level).

After reading jrkitching thread about the fluid being more than two years old (my car is 53reg Panda registered in Dec 03, I had the fluid checked by my local garage who confirmed (and showed me) that everything was ok (I got a little green light on a pipette style devise which tests the fluid)

So could the fluid still be best its past despite not having any moisture in it - it doesn't look cloudy at the bottom.

Since the Panda passing it's test in Dec the usuage has dropped off dramatically (even though I only did 6K in the previous year) and I wondered whether this has caused the problem to appear or maybe that is an unrelated guess.

Anyway will keep trying to resolve, thanks the posts as I would not be this far without them.
 
Confused of Hartlepool here,

I like Penguin have this problem.

I like Penguin initially thought the mats were the culprit.

Then after taking the mats out and it happening again I checked the fluid level as prescribed by M E P and everything was OK (i.e fluid to the correct level).

After reading jrkitching thread about the fluid being more than two years old (my car is 53reg Panda registered in Dec 03, I had the fluid checked by my local garage who confirmed (and showed me) that everything was ok (I got a little green light on a pipette style devise which tests the fluid)

So could the fluid still be best its past despite not having any moisture in it - it doesn't look cloudy at the bottom.

Since the Panda passing it's test in Dec the usuage has dropped off dramatically (even though I only did 6K in the previous year) and I wondered whether this has caused the problem to appear or maybe that is an unrelated guess.

Anyway will keep trying to resolve, thanks the posts as I would not be this far without them.

Whilst changing the fluid regularly is a worthwhile precaution against possible corrosion of the internal parts of the hydraulic system, I don't think it's the cause of this problem. My best guess is that something is worn or catching in the clutch pedal mechanics, which are in the footwell. Try looking carefully at the mechanism whilst operating the clutch pedal slowly by hand - some contortions might be necessary. See if you can feel the point in the travel where it's sticking, and look to see if you can see what's stopping it moving freely. Studying the photo I posted earlier may help you identify the parts you should be looking at. It's a bit awkward, because unfortunately the steering column shaft runs diagonally in front of the bits you really want to see.

While you're down there in the footwell, you could also check the master cylinder isn't leaking. This thread has a picture of what to look for:

https://www.fiatforum.com/500/293802-clutch-master-cylinder-leaking.html

Although this is from a 500, the mechanism & parts are identical.

Good luck & keep posting what you find.
 
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Apologies, I forgot to mention in my previous post that so far I had not checked what you have suggested above (but I intended to), which would have avoided you reposting your advice twice. Anyway will do so tomorrow when I have a little bit more time (as in I don't have my 3 year old boy trying to "help" me with the car which is slightly counter productive).
 
Right back again after several days of rain which prevented me looking at the car.

Blimey you weren't wrong about needing to be flexible to look under the pedal set, my back is aching!! Should have let me 3 year old little boy do the job...

Back to the subject in hand and after looking at the pedal twice now it look fine and by that I mean it looks like the jrkitching's fab photo's and doesn't "stick" anywhere on the travel down or up, am also trying to test the carpet to see if there are any signs of weeping fluid as per the other link in the post.

Failing all of that, it will be back to my local garage to check the fluid again or maybe even replace the fluid as a precaution or inspect the cylinders as abit worried about my brakes if this persists as the pdeal does feel softer than before (maybe a sign that one of the seals on the cylinders has gone)

As an aside I did have a new rear drum brake cylinder replaced recently and the brakes were bleed and could have caused this other part to fail (newest part causes next weakest part to fail?) & I have the famaliar clutch judder (but had this since owning the car) does this help in any way?
 
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?
 
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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.

I think the symptoms you describe are more indicative of the problem being mechanical that hydraulic. Look back at the pictures of the spring & nylon bush & see if you can feel anything when pressing the pedal by hand.

I'd be tempted to give the bush/spring a very light spray with a silicone rubber lubricant (not WD40!) to see if anything changes.
 
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Hi JRK - thanks. I have already tried that, without success I'm afraid. The springs under the pedal are a mystery, as the way they are set up, they actually don't push the pedal back upwards! You can 'prove' this by opening the bleed valve in the hydraulics: initially, yes the spring will try and return the pedal, but once past half way, the spring actually helps pull the pedal downwards, as it goes 'over centre'. I suspect the return force for the lower part of the pedal's travel is provided by the clutch diaphragm spring, rather than those under the pedal.

I have bleed it again this afternoon, this time with the pedal fully down (held by a piece of timber wedged between the seat the the pedal) and this does seem to have improved things further – certainly a rush of small bubbles came out when I opened the bleed screw (again using the pressurised Easibleed set up). I have a hunch that air is still my issue...
 
OK, Top Gear out of the way, back to the clutch

I decided the easiest way to see under the pedals was to point the camera up in there - and this is what it shows. First up, no spring like jrkitching's photos -- instead of one around the pedal pivot, a long spring mounted vertically between a lug on the pedal and the mounting frame, and that seems to all be in order. But second, note (more in the second shot, where the spring is hidden behind the steering column) the weepage of hydraulic fluid where the actuator goes into the master cylinder. Suspect that'll be the problem then...
 

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First up, no spring like jrkitching's photos -- instead of one around the pedal pivot, a long spring mounted vertically between a lug on the pedal and the mounting frame, and that seems to all be in order. But second, note (more in the second shot, where the spring is hidden behind the steering column) the weepage of hydraulic fluid where the actuator goes into the master cylinder. Suspect that'll be the problem then...

Yes, a different pedal arrangement to my 1.2, and the master cylinder is a different part also. Since it's obviously weeping, it would be a good idea to change it. And when it's removed would be an excellent time to double check that all is working as it should be in the pedal department. Looks like just a couple of nuts to undo on the bulkhead side (easily accessible on the 1.2; not sure about the Mjet) & I expect the ball & socket arrangement inside the car will just snap out.
 
update: I had another go at bleeding the system a week ago, and all has been fine since (over 400 miles, inc long trip to and round Peak District) . Bled with pedal fully depressed, then, with bleed screw closed again, pumped pedal several times to operate clutch, and bled again. Repeated a few times, each letting fewer bubbles out. Suspect 'leak' seen on cylinder in car was from spraying pedal pivot with lubricant, as cleaned off and no sign of a return.
 
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