Xantia 2.0 HDI hydraulics questions

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

Moderator: RichardW

Post Reply
christi
Posts: 26
Joined: 16 Dec 2004, 21:33
Location:
My Cars:
Contact:

Xantia 2.0 HDI hydraulics questions

Post by christi »

I actually have a Peugeot 806 HDI. The 806 / Expert / Synergie etc HDIs all seem to have the same problem which is that every one that I have driven with more than a few miles on it has a knackered power steering pump.
The HDI idles at only about 500rpm, and it simply isn't enough revs to develop enough hydraulic pressure to move the steering unless a brand new pump is fitted.
I am now on my second pump. A new one from Peugeot costs £270. A recon one costs £150 but one of those hasn't even lasted a year.
So my thinking is, could I fit a pump and accumulator sphere from a Xantia HDI (same basic engine) and run the system on LHM instead ?
Where is the pump located and what is it driven from on the Xantia HDI ?
Is the pressure in the Citroen hydraulic system in any way similar to that produced by a conventional power steering pump ?
Would the seals in the Peugeot steering control valve and rack be okay with LHM fluid in there instead of power steering fluid (ATF)?
Could a Citroen pump work with a power steering fluid reservoir or is there something special about the Citroen one?
User avatar
AndersDK
Posts: 6060
Joined: 21 Feb 2003, 04:56
Location: Denmark
My Cars:
x 1

Post by AndersDK »

The Citroen hydraulic system pump produces hydraulic pressure in excess of 300bar. The whole system is designed for LHM (mineral oil based). This is no good for the conventional power steering systems as all seals must be for LHM oil.
You can forget about adapting the Citroen system. It would be way too complicated and expensive.
It's much better to correct the original problem than trying to modify the existing system.
Any clues to why the original pump does not last ?
User avatar
Kowalski
Posts: 2557
Joined: 15 Oct 2003, 17:41
Location: North East, United Kingdom
My Cars: Ex 05 C5 2.0 HDI Exclusive 145k
Ex 97 Xantia 1.9TD SX 144k
Ex 94 Xantia Dimension 1.9TD 199k

Post by Kowalski »

The Xantia HDI hydraulic pump has two outlets, only one produces the 300bar Anders mentions, the other produces the pressure required for power steering. If you could replace your steering rack with a Xantia rack, you could swap over the pumps and run on LHM, otherwise you're going to run into seal compatability problems that Anders mentions. The pressure regulator and accumulator sphere would not be required (they are only needed if you have hydraulic suspension and brakes.).
I agree with Anders that it isn't a practical suggestion to swap over to LHM. If your pump can't produce enough volume at low revs, perhaps the pump is fine but the steering rack has an internal leak on it.
christi
Posts: 26
Joined: 16 Dec 2004, 21:33
Location:
My Cars:
Contact:

Post by christi »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Kowalski</i>

perhaps the pump is fine but the steering rack has an internal leak on it.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I will have to look into that. I will be a little upset if I have changed out a perfectly good pump.
jeremy
Posts: 3959
Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
My Cars:
x 2

Post by jeremy »

I doubt if the unused part of the Citroen pump would be happy running dry. The earlier BX ones have only one output and so this problem would not arise.
The Citroen pump is as far as I know all metallic inside with just a shaft seal. As TQF is mineral based I don't see any problem running the citroen pump on this.
However seems something strange happening here as PAS pumps generally are reliable. 500 seems a bit low for an idle - would have thought 750 was more appropriate.
jeremy
User avatar
Kowalski
Posts: 2557
Joined: 15 Oct 2003, 17:41
Location: North East, United Kingdom
My Cars: Ex 05 C5 2.0 HDI Exclusive 145k
Ex 97 Xantia 1.9TD SX 144k
Ex 94 Xantia Dimension 1.9TD 199k

Post by Kowalski »

The unused part of the pump wouldnt run dry, since there is only one input to the pump. It would end up pumping LHM constantly which would affect fuel consumption. The pump is variable output so possibly it could be blanked off although I'm not sure whether that would be possible or whether you'd have to blank it with a pressure release valve or similar.
jeremy
Posts: 3959
Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
My Cars:
x 2

Post by jeremy »

Thanks Kowalski - of course it has on input. I suppose since they are 6 x 2 the best thing would be to re-circulate the output from the 2 pistons which would be spare - or alternatively if its all the same pressure (ie pump cylinders the same,) they could be joined together providing a single output.
jeremy
Post Reply