Xantia rear suspension

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mcgregor
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Xantia rear suspension

Post by mcgregor »

My 2001 HDi has recently started sagging at the rear end when left for a few hours. Once engine started it only takes a few seconds to get up to correct ride height. I certainly never did this before and has only started in the last week or so. Could the problem be the accumulator sphere the anti-sink sphere or is there a check valve of some sort leaking? Any ideas greatly welcomed.
Cheers
Dave
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Post by CitroJim »

Hi Dave,

Have a look through this thread for a bit of background to this issue.

http://www.frenchcarforum.co.uk/forum/v ... hp?t=22831

The most usual cause is a weak accumulator or weak rear suspension spheres. As you will see, the rear anti-sink sphere is mis-named although it is involved in the process, ensuring the rear anti-sink valve closes positively and remains shut.

Leaks anywhere in the hydraulic system can also cause the problem and in my experience, it only takes a very tiny leak to cause sinking.

Does your car have Hydractive (a sport/comfort switch on the dash)? Hydractive cars have more hydraulics to check whilst chasing tjios problem.

The following is a very valuable "bible" on Citroen Hydraulics. It gives a very good understanding of the subject.

http://www.tramontana.co.hu/citroen/guide/guide.php
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
mcgregor
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Post by mcgregor »

Jim
Thanks for that. No it is not a Hydractive car and has the standard 6 spheres. It is now 7 years old, done 102K miles and I changed out the suspension spheres in December for the first time in its life so I guess the anti-sink and accumulator are both due a change as well.
Don't much fancy doing the anti-sink one though it looks as if it might cause problems. Might be easier than the anti-sink valve as a first port of call though.
Having read the anti-sink bit in the "Citroen Guide" it looks like the anti-sink valve acts like a sort of check valve but only if it has pressure from the rear sphere to hold it.

Cheers
Dave
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Post by DaveW »

Dave,

The anti-sink/rear accumulator is not hard to do.
Unlike the corner spheres and main accumulator, the threads on the anti-sink sphere simply screw into a threaded bracket. You MUST undo the union that connects the high pressure LHM feed to the sphere (after the usual de-pressurising procedure) before attempting to remove the sphere.
A squirt of release oil (WD 40 etc.) on the exposed threads will make unscrewing the sphere easier.


Dave.
Xantia Forte 1.8i, 16v X reg.(09/2000) 93K, aircon
mcgregor
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Post by mcgregor »

Thanks guys. Will this be ok to leave for a while until we have better weather as it will have to be done outside on ramps. If not I guess I shall have to put it in to the local Citroen guy to get done.
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Dave
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Xaccers
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Post by Xaccers »

If you haven't got a pliedes, make yourself one of these.

http://www.frenchcarforum.co.uk/forum/v ... hp?t=21850

You don't happen to live near Buckingham I suppose?
I have reasonable access to some WW2 inspection ramps which are ideal for working on Xantias (unless you suffer from vertigo!)
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
mcgregor
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Post by mcgregor »

Thanks for the offer much appreciated but NE Scotland I'm afraid.
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Post by Xaccers »

Use the time until the weather gets better to buy yourself an 8mm and 9mm flare spanner (pretty sure the AS pipe union is 9mm, while the the brake bleed nipples are 8mm but someone will correct me if I'm wrong).

Have you done a hydroflush yet and cleaned the filters in the LHM tank?

If you haven't, it'll be worth while doing as it should have been done at 72,000 miles, though with a LHM change at every 36,000 miles and Hydrorincage being about £20 from GSF, many people flush every 36,000 miles.

The BoL covers the proceedure quite well.
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
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Post by CitroJim »

Don't forget to replace the 3.5mm rubber hydraulic seal on the pipe when replacing the Anti Sink sphere. You may think there is no seal as the old one usually ends up remaining in the sphere.

The seals are available from GSF for pennies and it is a good idea to hold a selection in stock as they're used all over the hydraulic system.
Jim

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DaveW
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Post by DaveW »

mcgregor wrote:Thanks guys. Will this be ok to leave for a while until we have better weather as it will have to be done outside on ramps.
I did mine with the rear of the car on axle stands. As I said, it's not a difficult job and you should be able to do it in about 30 minutes start to finish including clean-up (there will be a small amount of LHM spillage).

The 'P' tool described in Xac's link is well worth making if you think you will be replacing a lot of spheres and is very efficient. An alternative method - if a chain wrench won't 'start' the sphere (which it may well do on this one) - is to to link a couple of 'Jubilee' clips together to make one large enough to fit the sphere, tighten it around the sphere and give it a good clout with a hammer via a blunt cold chisel. This will usually break the seal sufficiently to allow you to remove the sphere by hand the rest of the way.
I used this method successfully to do all the sphere work on my old BX.



Dave
Xantia Forte 1.8i, 16v X reg.(09/2000) 93K, aircon
mcgregor
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Post by mcgregor »

Thanks for all the help and advice guys.
Dave
mcgregor
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Post by mcgregor »

For some weeks now my Xantia rear has been sinking when left for a few hours hence my question. Suddenly two days ago it stopped doing that and all seems to be well now even when left overnight. I am absolutely baffled as to why this should happen. Any ideas?
Cheers
Dave
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