XM mk2 LHM change & power steering

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nino1
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XM mk2 LHM change & power steering

Post by nino1 »

Hi,

A week ago a complete lhm change was performed on my 98 XM.
The "lhm" that was extracted was, for a lack of a better word, mud.
It was barely transparent brownish :shock:
Anyhow after the change the improvements in the softness and servo are significant.
However i do have a few questions.

One is the power steering (it's not diravi). When idling and moving the wheel besides from the revs coming up very slighty (afaik normal), i get a sound that resembles fluid wooshing through something (my best description).
When riding slowly it is barely noticable only near the wheel lock to the either side.

The second is the rising/droping.
The anty-sink works flawlesly, and the initial leveling after starting the engine is significantly faster.
On the other side response to the height weel changes is way slower since the lhm change.
The drop happens nice and smooth (tho i sometimes get some sudden droping for a sec, then it resumes normaly)
The rising from the lowest to the normal position takes ages if not assisted by the gas pedal :)
From normal to top position the rear does so straight away but same as above for the front.
Brakes and suspension feel better excellent.

Also if i rev it the power steering seems to loosen some, but the speed sensitive part feels tight as you go faster.

Tnx
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AndersDK
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Post by AndersDK »

3 quick shots :

1) Citaerobics (full ups & downs) were done intensively ?
2) and then the brakes were bled out the old fluid ?
3) dead sure the pump intake side (reservoir feed) rubber hose is leaktight - on studs - & over the complete run (leaktight = vacuum tight ! )?

I seem to remember the whooshing sound from the XM PAS is a telltale on something no longer in fresh condition - try a forum search. Its definately been discussed before.

BTW : peep in on this related thread :
http://www.frenchcarforum.co.uk/forum/v ... hp?t=17901
Anders (DK) - '90 BX16Image
nino1
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Post by nino1 »

Brakes were not bled, it was done trough the return pipe.
Citrobics then bled, then topped up and then bled some more with the engine running.

Accumulator sphere, and gearbox oil also changed.
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AndersDK
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Post by AndersDK »

nino1 wrote:Brakes were not bled, it was done trough the return pipe.
You mean the brakes were serviced/overhauled and all caliper pistons bottomed in the bores ? (after Citaerobics)

If not - then the brakes were never bled at all !
Anders (DK) - '90 BX16Image
nino1
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Post by nino1 »

No service was done on the brakes, shouldn't the fresh lhm circulate a bit through them?
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AndersDK
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Post by AndersDK »

How would the fluid circulate in the calipers ?

- are you using modified calipers on your XM ? :wink:

The calipers are dead ends in the system. As the discs and pads wears over time - more and more of the fluid residing in the pipes is moved into the caliper cavities - but never returned.

Life aint that easy - sorry :lol:

So out for a regular brakes bleeding job you are 8)
- and you'll again have a date with that muddy fluid I bet.
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nino1
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Post by nino1 »

So it seems.
Maybe the other problems can be associated with the pump/belt area.
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Post by jeremy »

If you are still getting strange noises it sounds to me that air is getting into the system. The likely culprit is the hose from the reservoir to the pump which was probably removed at the reservoir end for priming purposes. The end may be loose or split - but its worth investigating. Have a careful look at the pump end to see if that has been disturbed - if not its probably OK but otherwise do the same here and look at the pipe connection or whatever to the pump - as some Xantia's can leak here with the connectin to the body of the pump or something giving trouble.

You may be able to see something resembling green milk in the reservoir - this is a sure sign of air.
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nino1
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Post by nino1 »

Can't really see where the air would be getting in.
I know its pressurised but wouldn't i at least get a drop of lhm under the car after being parked for longer periods of time?
Anyhow i'll be getting a new pump so with a bit of luck...
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Post by jeremy »

Air can only get in on the suction side of the pump. The pressure on the outlet side is enormous and will find any weak point and leak.

If your pump was working before it should work now. As I suggested above check the pipe from the reservoir to the pump very carefully - and I'm certain you will find the problem and probably be able to cure it at no cost or for the cost of a hose clip.

If you search this board you will find that this is quite a common problem.
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Post by Robin »

On reading everything through I can say that the 'whooshing' sound at extreme steering lock ends is normal, it is the excess fluid passing via a relief valve, just ease off the steering and it stops.
Brakes, sorry but they will need flushing/bleeding through, and yes that muddy stuff again.
As for slow rising, the front will be slower to rise than than the rear because it's heavier with the engine.
When lifting from a totally down condition it does take a while because the pump has to repressurise the whole system, accumulators and all the spheres before the system can start to lift the car.
Great cars these XM's! :D
Citroens are dedicated to those who take a big bite - and just keep on chewing!
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Post by Peter.N. »

If the 'rise time' is longer than it was, just check the tension on the hydraulic pump belt.
nino1
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Post by nino1 »

So, to finish the job i need to bleed a bit of oil (how much?) from the four ends and then topup the lhm if needed?
andmcit
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Re: XM mk2 LHM change & power steering

Post by andmcit »

nino1 wrote: One is the power steering (it's not diravi). When idling and moving the wheel besides from the revs coming up very slighty (afaik normal), i get a sound that resembles fluid wooshing through something (my best description).
Also if i rev it the power steering seems to loosen some, but the speed sensitive part feels tight as you go faster.
The wooshing sound is common on Xm DIRASS steering as well as the DIRAVI type. Nothing to worry about.

Thing is, if your V6 is a non DIRAVI, it wont have speed sensitive steering...

Andrew
nino1
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Post by nino1 »

You are right, its not DIRAVI.
Never given it much thought but i does seem tighter at higer speeds
(as at lower speeds for that matter :))

But, how about the amount of oil to be bled from the brakes? :)
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