C5 hdi back end sinking

toldem_oldham · Post by **toldem_oldham** » 31 May 2008, 16:46

Hi all my c5 hdi has all of a sudden has decided to sink after car has stopped for more than 1 hr ,there is no sign of a leak plus when i click the remote to open the car i can hear the motors working for longer than normal so i know something is not right

marsalek · Post by **marsalek** » 31 May 2008, 19:16

IMO it has nothing to do with height correctors or spheres. There is an antisink valve, that probably does not close (hangs). Maybe due to some dirt in LHS. Mine on Xantia behaved the same way two weeks in winter but all of the sudden, the problem disappeared by itself. The same happened to another colleague from a german xantia forum. If I were you, I would just wait a couple of weeks and if it doesn't cure by itself, you will probably need a new antisink valve. Those on C5s cannot be IMO serviced.

Karel

AndersDK · Post by **AndersDK** » 31 May 2008, 22:29

toldem_oldham wrote:when i click the remote to open the car i can hear the motors working for longer than normal so i know something is not right

Which motors ?

wheeler · Post by **wheeler** » 01 Jun 2008, 00:15

I think he means the pump motor in the BHI, when you unlock the car the BHI primes the suspension.
The antisink valves are an internal part of the BHI but i reckon the sinking is more likely to be caused by internal leakage on the rear suspension cyliders.

AndersDK · Post by **AndersDK** » 01 Jun 2008, 00:29

Tx Wheeler -

Could not make any sense of buzzing or whirring motors - except exactly the BHI.
I have found that the dreaded rearsink on the earlier BX'es is really down to leaking rear suspension cylinders. Not the brake valve as suggested by many (including me myself

).
Since the later Xantia & C5 is of exactly the same construction, its likely to be the same problem.

Next question is why they develop this leak, as there is both a tephlone and rubber O-ring to seal off the cylinder piston.

mooseshaver · Post by **mooseshaver** » 01 Jun 2008, 11:40

My rear suspension cylinders went at 6 years. Perhaps all the 02 ones are due to go?
I thought it was because we often carry a 19 stone disability scooter in the back.

toldem_oldham · Post by **toldem_oldham** » 02 Jun 2008, 17:35

I was under the car today and could not see any visible leaks or even any wet patches sugesting a slight leak

mooseshaver · Post by **mooseshaver** » 03 Jun 2008, 08:52

toldem_oldham wrote:I was under the car today and could not see any visible leaks or even any wet patches sugesting a slight leak

Mine never had any patches on oil on the ground when I parked. I jsut took it in for a service and MOT and was told they wouldn't let me drive it away again because it was leaking!

AndersDK · Post by **AndersDK** » 03 Jun 2008, 19:32

toldem_oldham wrote:I was under the car today and could not see any visible leaks or even any wet patches sugesting a slight leak

Which is the most common reason to why owners find this problem a mystery !

The leak is NOT external. No external drippping, weeping or seepage.
Not even a trace of it.

The leak is INTERNAL. Thats why you have the 2 hoses attached to the rubber bellow : the rearmost of these is the leakback hose returning the cylinder leak to the resevoir, while the frontmost is the vent hose to vent the bellow when it compress/extend during movements.
Note that the cylinders are DESIGNED to leak a small amount past their seals, to keep the piston and its seals lubricated. Its just that the piston seals takes this lubrication job a bit too serious over time ...

Post by **myglaren** » 03 Jun 2008, 19:38

Which is probably the explanation for mine - there is a very slight weep on the rear offside, going in on Thursday for a bit of a checkover and a few minor odds and ends done, including that.

Guy anticipated that it would likely be the bellows weeping a bit as it has happened on a few he has fixed of about the same vintage.

bencowell · Post by **bencowell** » 04 Jun 2008, 19:04

myglaren wrote:Which is probably the explanation for mine - there is a very slight weep on the rear offside, going in on Thursday for a bit of a checkover and a few minor odds and ends done, including that.

Guy anticipated that it would likely be the bellows weeping a bit as it has happened on a few he has fixed of about the same vintage.

How many miles have you got?

Post by **myglaren** » 04 Jun 2008, 19:15

bencowell wrote:
myglaren wrote:Which is probably the explanation for mine - there is a very slight weep on the rear offside, going in on Thursday for a bit of a checkover and a few minor odds and ends done, including that.

Guy anticipated that it would likely be the bellows weeping a bit as it has happened on a few he has fixed of about the same vintage.

How many miles have you got?

A little over 120,000.

bencowell · Post by **bencowell** » 04 Jun 2008, 21:25

Did you have the rear suspension replacement? I wonder if having mine taken apart at 12k miles will make it last longer!

Do you do Citraerobics?

den169 · Post by **den169** » 15 Aug 2008, 18:47

My brother had this problem with his c5 for about 5 months then it just stopped doing it and has been ok for about 2 months now.

Post by **myglaren** » 15 Aug 2008, 19:35

Forgot to report back to this thread.
If it was aimed at me, yes I do do Citaerobics, the only kind of excersize I get

The bellows were replaced, cost around £12 and there has been no reoccurence.

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C5 hdi back end sinking

C5 hdi back end sinking

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