In my Xantia, the high impact sound in small pits

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DrXantia
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In my Xantia, the high impact sound in small pits

Post by DrXantia »

Hello friends,
I live in Turkey and I have a problem for a long time which I could not solve unfortunately.
Last year, I renewed all 6 balls (I do that every 5-6 years) But my problem is that the problem with the back of smaller gaps always get very hard shock. As if someone had hit with hammer.
But at normal speed, the suspension is very nice. I cleaned the rear height corrector 3-4 months ago. At the front, the brake doser and regulators height clean and all o-ring parts renewed.
With new start at least 15 sec. I get the desired height.
So what can be the problem?
I'm looking forward to your solutions.

Sorry for bad translation from german to english

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white exec
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Re: In my Xantia, the high impact sound in small pits

Post by white exec »

What you describe - Hydractive suspension being crashy over small and sudden changes in road surface, especially at the rear of the car - is something which XM and Xantia owners have suffered from for some time, when a sudden small ridge/bump is taken a bit too fast.

Even when everything is working properly...
- good spheres, at correct pressures
- no air trapped in the LHM system
- tyres not over-inflated
- suspension (Soft and Firm modes) working ok
- no other mechanical problems
...the problem can still be there.

Back in 2016, there was a bit of a breakthrough here, when we found that Xantias, from RP8155 (8 March 1999) onwards, had been fitted with an improved type of front and back suspension regulator valve.

If your car is before RP8155, you would benefit from fitting the late-type, improved valves.
The RP number should be on the car, but if in doubt, just post your VIN number (which will be masked), and we can find it for you.

There is a thread here on the Forum which describes how to change the two valves:
viewtopic.php?f=3&t=55429&hilit=Evoluti ... 30#p505370 .

The thread is worth reading from the start (go to page 1 of it, by GiveMeABreak, 27 June 2016), if you would like lots of bedtime reading. :wink:

No problem with your translated post, by the way. All easy to understand.
Let us know some more when you can.

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DrXantia
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Re: In my Xantia, the high impact sound in small pits

Post by DrXantia »

My vehicle is not hydractive.

Thank you for the information.
I'm gonna read the subject. (I'll translate it into German) :)

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white exec
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Re: In my Xantia, the high impact sound in small pits

Post by white exec »

OK, that sorts that. Forget about the valves. My error.

Pop up your VIN, and we'll check the exact spec (volume, pressure, damping) for the spheres you should have.

Other common cause of crashiness is over-inflated tyres, or air in the LHM.

Dip a sample of LHM from the reservoir, after the car has been driven a km or so, with a small transparent container. The LHM should not contain air bubbles, even small ones. If air is there, first check the suction pipe (from reservoir to pump) for splits or bad connections at each end.
Also check LHM level is correct, and that the two filters in the tank are not missing/broken/blocked.
The filters have the function of de-aerating the fluid, as well as catching dirt.

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DrXantia
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Re: In my Xantia, the high impact sound in small pits

Post by DrXantia »

white exec wrote:
25 Apr 2019, 22:27
OK, that sorts that. Forget about the valves. My error.

Pop up your VIN, and we'll check the exact spec (volume, pressure, damping) for the spheres you should have.

Other common cause of crashiness is over-inflated tyres, or air in the LHM.

Dip a sample of LHM from the reservoir, after the car has been driven a km or so, with a small transparent container. The LHM should not contain air bubbles, even small ones. If air is there, first check the suction pipe (from reservoir to pump) for splits or bad connections at each end.
Also check LHM level is correct, and that the two filters in the tank are not missing/broken/blocked.
The filters have the function of de-aerating the fluid, as well as catching dirt.


You Mean that : VF7**************[VIN obfuscated, can be read by forum staff] ?

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GiveMeABreak
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Re: In my Xantia, the high impact sound in small pits

Post by GiveMeABreak »

He has a Series II XANTIA II 5 Door Saloon 2.0 i 16v 135 with Manual gearbox 5 Chris, non hydractive as said.

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xantia_v6
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Re: In my Xantia, the high impact sound in small pits

Post by xantia_v6 »

As Chris has said, one of the most common causes of harsh suspension (particularly at the rear) is due to air in the hydraulic fluid. The usual cause is a split hose between the LHM tank and the pump, although there have also been cases reported where the lid of the LHM tank had a defect causing a leak, or the shaft seal of the LHM pump leaking, allowing air to be sucked in.

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DrXantia
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Re: In my Xantia, the high impact sound in small pits

Post by DrXantia »

xantia_v6 wrote:
25 Apr 2019, 23:48
As Chris has said, one of the most common causes of harsh suspension (particularly at the rear) is due to air in the hydraulic fluid. The usual cause is a split hose between the LHM tank and the pump, although there have also been cases reported where the lid of the LHM tank had a defect causing a leak, or the shaft seal of the LHM pump leaking, allowing air to be sucked in.


OK. Thank you very much

I'll try to check everything from tomorrow stage to stage.
I hope I find the problem.
I'll get back to you.

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white exec
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Re: In my Xantia, the high impact sound in small pits

Post by white exec »

This is the full spec for the non-HA Xantia spheres...

Click to enlarge
Xantia non-HA sphere specs.JPG
Ignore the part numbers, which have changed.

If using non-genuine Citroen spheres, make sure the Damper hole diameter is correct, because this will directly affect how the car damps out sudden surface changes. Some aftermarket suppliers don't seem to list it, which isn't helpful.

Hope useful.

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DrXantia
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Re: In my Xantia, the high impact sound in small pits

Post by DrXantia »

Hello friends
Have not written for a long time because I would like to determine the problem exactly.
So after your instructions, I checked the LHM depo and followed it several times under different circumstances. Not seen a bubble.
But I realized that this shock has also started in the front of the car.
I suspect that it may be a problem of the pump? But I'm not sure.
Because, at the rear height corrector, I noticed a little bit very low-viscosity oil.
I have a drop of drops daily at the regulator.
But I've also had that before. This could not be the cause.
What do you think. Which options do I have to control?

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white exec
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Re: In my Xantia, the high impact sound in small pits

Post by white exec »

Small amounts of LHM fluid (= low viscosity oil) dripping is usually from the low pressure rubber pipes (and rubber joiners) of the fluid return system. (A leak from a high-pressure steel pipe or joint will usially be a seriously rapid one.)

Try cleaning up and drying off the leaky area, and trying to find exactly where it is leaking from. A split rubber pipe, or rubber elbow, is not uncommon.

Good that there are no bubbles in the fluid reservoir.

Is the car riding at the correct height? Too high, or too low, can result in harsh/crashy suspension.
Try moving the height control lever by a small amount each way, either side or Normal, and see whether it improves the ride quality.

On Normal height, with engine running, if you push down on the front of the car, and then the back end, does the suspension feel soft and springy, or does it feel firm?

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DrXantia
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Re: In my Xantia, the high impact sound in small pits

Post by DrXantia »

Thank you,
I think I will uninstall the rear height corrector and check everything.