C5 clutch master cylinder

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
bencowell
Posts: 507
Joined: 20 Oct 2002, 13:47
Location:
My Cars:
x 1

C5 clutch master cylinder

Post by bencowell »

Having written here previously about the moving biting point on my 43,000 mile 2002 model C5 2.0 HDI 110, and the dealer finding nothing wrong while in warranty, I feel the symptoms are getting worse now.
When holding the clutch down for any legnth of time, say 5 to 10 seconds, while the engine is hot, the biting point moves so that the slightest movement of the clutch makes it bite. A few more presses of the clutch, say 1st to 2nd gear, and 2nd to 3rd while moving, and the clutch feels normal again.
There is no slippage and I do not 'ride' the clutch, I match my gears and revs well when changing, so I am sure there is minimal wear to the friction material.
Having inspected, and the garage done the same, there is no fluid leakage.
I have obtained prices for the master and slave cylinders to be replaced, the master is a very long job, taking about 3 hours, the slave is well under an hour.
Do you think this is definatly the master, or is it worth changing the slave first to see if it makes a difference?
Thanks in advance
Ben
jeremy
Posts: 3959
Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
My Cars:
x 2

Post by jeremy »

Assuming its of normal master and slave cylinder designthen your problems sound like air in the system. The old curse used to be leaking slave cylinders (much more rapid than brake cylinders as the things travel miles further) but these usually bled themselves through the leaky seals and would go on for a long time being a bit messy. The give away for a leaking master cylinder was that fluid would often leak down the pedal and dissolve the paint.
What I think is happening is that air in the system expands when the clutch is not being used and pushes the fluid back to the reservoir, giving a soft pedal whan first applied. Pumping the pedal compresses the air and admits more fluid making it work properly and then the cycle repeats itself.
I don't know if there is a bleed nipple on the slave cylinder but if not you will probably get much the same result if the hydraulic pipe is loosened while someone presses the pedal down, tighten and do the same again.
I have seen somewhere that this system is sealed. It would normally be necessary to top up during bleeding but this may be a problem. However as the dealer seems able to replace individual components there must be some way in.
Jeremy
Sir Clive

Post by Sir Clive »

Surely its the slave cylinder thats going to be the long job? As far as I know, the slave cylinder is one of those annular jobbies that hides in the clutch housing, and requires the engine and 'box to be split to get at it?
I also found this on Honest John's website which may have some relevance:- EU wide problem with clutch of HDIs: release bearings are failing on average at 30K miles and the hydraulic actuators at approx 70K miles. Both cause significant damage (£700 - £1000) to repair. Basically, the clutch assembly "blows-up", though not the actual clutch disc, which can have as little as 20% wear.
Perhaps it should be investigated now before it does cause any damage?
406 V6
Posts: 593
Joined: 02 Sep 2004, 01:52
Location: Lisboa, Portugal
My Cars:

Post by 406 V6 »

Ben, i've been told several times (as i suspect i have a problem on the dual-mass flywheel of the C5 - the engine starts shaking after a bit of stop-and-go at city traffic) that even if the problem hasn't been taken care of or correctly diagnosed while on warranty, and been reported, the dealer/Citroën can at least absorb some part of the cost of replacing the component, after the warranty period.
I know this doesn't help with your particular problem directly, but may help out your wallet :-/
Sir Clive

Post by Sir Clive »

I'm sure that it's only the 2.2 litre engine that has the dual mass flywheel, the 2 litre has an ordinary one.
bencowell
Posts: 507
Joined: 20 Oct 2002, 13:47
Location:
My Cars:
x 1

Post by bencowell »

I've been told that the 2.0 has a dual mass flywheel too.
The slave cylinder is well under an hours work. Hmmm.
Does anyone know the signs of a dual mass flywheel failing?
I really hope it isn't that as that would be an engine/gearbox out job. Shame cos the car was in the dealer a month ago and the warranty finished 3 weeks ago.
406 V6
Posts: 593
Joined: 02 Sep 2004, 01:52
Location: Lisboa, Portugal
My Cars:

Post by 406 V6 »

if you mentioned that problem last month, still under warranty, try to talk to the dealer and see what you can get.
It' seems that when it starts to fail the engine starts to vibrate as there is no simetry on the flywheel weight as it rotates.
Newer C5's have that fixed [:(].
A bit of-topic, but Ben, does your HDI make a squeal when pressing/releasing the clutch? I was told it's a 2.0HDi thing not a problem. Oh well...
Best of luck[;)]
bencowell
Posts: 507
Joined: 20 Oct 2002, 13:47
Location:
My Cars:
x 1

Post by bencowell »

No, the clutch is silent. Dad's 206 (3 years long gone!) squeaked when you pressed the clutch. It was the release bearing. They went many times, but my Xsara with the same engine and gearbox didnt have the problem, different clutch maybe.
I sometimes get a small vibration at idle speed when the car is half warm, not hot or cold.
bencowell
Posts: 507
Joined: 20 Oct 2002, 13:47
Location:
My Cars:
x 1

Post by bencowell »

Some posters on HJ's site suggest air in the system or a faulty pressure plate. Any ideas from the Citrophilles?
Post Reply