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Clutch issue - advice gratefully received

A993LAD

Hockenheim
Joined
20 Mar 2007
Messages
721
Hi folks

Suddenly encountered a problem with my clutch pedal/clutch action and would be grateful for any thoughts on whether I should try and find the cause so I can fix it or just take it to a workshop.

Got in the car at the weekend and noticed that the clutch pedal was much lower down than I expected it to be and the clutch action was greatly reduced - i.e. the car goes into gear okay, but you hardly have to release the pedal before the car starts moving. Normally the pedal sits much higher and the biting point is quite high when pulling away.

Anyway, I decided to take the car out for a spin and the pedal action and position improved very quickly on my journey such that after only a few miles everything seemed normal again.

Parked the car up overnight, but when I went out in it the following morning the clutch pedal was low again and the biting point was low. After a quick run to the shops, once again the pedal was back to normal position.

What would be causing this?

The symptoms, when the pedal is low and action is short, are similar to what happened a few years ago when my slave cylinder failed and at that point I replaced it with an MPL one which I've been very happy with. Could this one now have also failed? When the original clutch slave cylinder failed the problem just got worse and worse the more I drove the car to a point where I could barely get it into gear until the new slave cylinder had been fitted. Where is this time the problem quickly disappears if I drive the car a short distance.

I was thinking perhaps there was a leak somewhere in one of the connections so when I parked the car up air is leaking into the system. But surely I would then get hydraulic fluid pumping out of the hole and the fluid level would drop. I have checked it a couple of times now and the fluid remains at the high mark in the reservoir.

Any thoughts or suggestions will be much appreciated
 
I would lean towards it being air in the clutch hydraulic system , any mechanical fault would tend to be permanent .

You could try pumping the pedal like mad the next time and see if it gets better .

If slave cyl replaced then you also have master cyl .. not seen a pipe leak yet but always possible.

Theres not a huge amount of fluid in the system and it only takes a small amount of air so i doubt you would see the lvl drop .
 
Can you hook your foot under the pedal and pull it up to normal when this happens? If yes, it's probably this:

http://p-car.com/diy/pedal/clutchlever.html

I had this problem when I bought my car in 2011, Northway changed the slave cylinder and it was fine for a few years, then started again.

Had the new kinematic lever fitted last year and all is now fine (but time will tell).
 
martinfc said:
Can you hook your foot under the pedal and pull it up to normal when this happens? If yes, it's probably this:

http://p-car.com/diy/pedal/clutchlever.html

I had this problem when I bought my car in 2011, Northway changed the slave cylinder and it was fine for a few years, then started again.

Had the new kinematic lever fitted last year and all is now fine (but time will tell).

Thanks Martin

Once I've used the pedal a few times it comes back up to the normal location and the clutch works as normal. So I suspected something to do with the hydraulic fluid but I will try pulling it up manually before I use the car next to see if it is the issue you describe.
 
Hi Marc

I recently did some work on a 4S that had the same symptoms as you describe.

We changed the kinematic lever (It was already fitted with the later one), the spring and plastic item in the clutch pedal assembly.

We then bled the system and it has worked without incident for the last couple of weeks. (originally it played up on every trip)

My current assessment is that the bleed/fluid change that made the difference rather than the components that were fitted.

My ramp is free this weekend if you fancy a run over to bleed the clutch.
 
martinfc said:
Can you hook your foot under the pedal and pull it up to normal when this happens? If yes, it's probably this:

http://p-car.com/diy/pedal/clutchlever.html

I had this problem when I bought my car in 2011, Northway changed the slave cylinder and it was fine for a few years, then started again.

Had the new kinematic lever fitted last year and all is now fine (but time will tell).

A quick update on this - pulling the clutch pedal backup as you described has for now rectified the problem. So, you are spot on and I'm grateful for the tip.

However, does this mean that my clutch pedal is worn or has a fault and will continue to present this problem on a regular basis?

If so, then I guess I also need to fit the Kinematic lever.

Kevin - thanks for your offer to help bleed the hydraulics. But as the problem is rectified - although maybe only temporarily - I'll keep driving it for a while and see what happens.
 
I can only tell you my experience, which is:

- Once it started it didn't go away of its own accord and became annoying in stop/start traffic
- The first repair of new slave fixed it for about three years then it came back
- The last repair was the new kinematic lever last year BUT, they also changed the Master, it's been fine since, but can't be sure which fixed it or now long it will last...

My amateur advice would be have the slave inspected and if it's ok leave it, replace the Master and update to the latest kinematic and see how you go.

HTH
Martin
 
The two problems can be interconnected. Bearing in mind that the return action of the clutch pedal is derived from the spring action of the clutch pressure plate, and that this action depends on the hydraulic action of the slave cylinder acting against the master cylinder. In turn the master cylinder is directly connected to the clutch pedal.

A leak in the slave cylinder can cause the pedal to not return fully. Hooking the pedal back up and using the clutch causes the master cylinder piston to move to its fully "up" position, at which point fluid can flow from the clutch fluid reservoir into the clutch master cylinder, replenishing any loss. Hence the problem appears to be resolved for the time being.

Equally, if the clutch mechanism including the kinematic lever and master cylinder, gets dirty with dust and old grease, the friction here can cause the pedal to be reluctant to come fully up.

If the new aftermarket slave cylinder you had fitted didn't have a new dust boot fitted it is quite likely that the old boot (no boot?) is letting dust into the slave cylinder, which will lead to rapid failure of the slave cylinder piston seal. No choice but to replace the seal (checking the cylinder is still OK) and refitting with a new dust seal. Unfortunately these only seem to be available as part of the original pattern slave cylinder, which is why these alloy slave cylinders get fitted with an old or no dust boot (they're not supplied with a boot).

In my view therefore the only proper cure is:

i) Replace kinematic lever and ensure clutch pedal assembly and master cylinder are in excellent condition and fully greased and clean.

ii) Ensure slave cylinder is working properly (no leaks) and fit it with a new, working dust boot.

Anything less is only a temporary fix and you'll end up doing the job again in a few thousand more miles.
 
9xxnick said:
Anything less is only a temporary fix and you'll end up doing the job again in a few thousand more miles.

So for most owners it should last 7-10yrs then :grin:
 
Zingari said:
9xxnick said:
Anything less is only a temporary fix and you'll end up doing the job again in a few thousand more miles.

So for most owners it should last 7-10yrs then :grin:

We have put 22k miles on this 993 In the last three years, so it's certainly no garage queen, that's for sure.

The clutch seems to be back to normal since I pulled the pedal up to its normal position and have done about 350 miles without any re-occurrence of the problem so far.

I'm tempted to just keep driving it and see how quickly it crops up again in which case I will have to investigate more thoroughly, so thanks for all the tips about what to rectify.

I'll update this thread. If there are any more developments
 

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