Is there a rebuild manual for Xantia hydraulic pump?

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atr
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Joined: 09 Oct 2010, 05:02

Is there a rebuild manual for Xantia hydraulic pump?

Post by atr » 13 May 2018, 14:08

I would like to rebuild my Xantia's (II, petrol, 2001) hydraulic pump. the reason is that the steering is a little hard to turn and I suspect that the pump is weak (btw- I was thinking to connect a pressure gauge to the output of the pump to measure the pressure it provides, but I dont know how much psi/bar is the right value. if you have the data - I'll be glad to hear). and therefore I think that it needs a rebuild and I would be happy to get a manual to carry out the task.
Thanx.

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xantia_v6
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Re: Is there a rebuild manual for Xantia hydraulic pump?

Post by xantia_v6 » 13 May 2018, 16:07

Most people have their pumps reconditioned by Pleiades, but if you want to do it yourself, see this description of a rebuild of an earlier BX pump:
https://bxclub.co.uk/forum/viewtopic.ph ... ld#p263827

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Mandrake
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Re: Is there a rebuild manual for Xantia hydraulic pump?

Post by Mandrake » 13 May 2018, 16:30

xantia_v6 wrote:
13 May 2018, 16:07
Most people have their pumps reconditioned by Pleiades, but if you want to do it yourself, see this description of a rebuild of an earlier BX pump:
https://bxclub.co.uk/forum/viewtopic.ph ... ld#p263827

I don't think you could glean much useful info from that thread - it looks like BX pumps are designed completely differently to Xantia pumps.

The BX pump apparently needs a press to push the pulley off - not needed for a Xantia pump, (unless you're replacing a leaking shaft seal) as the triangle bit holding the pulley just unbolts, so you can withdraw the main shaft/cam.

Ball bearings and a needle roller race are shown in the BX pump - there are none in the Xantia pump, which just uses LHM lubricated bronze bushes.

The BX pump appears to be a multi-piston swash-plate design like the earlier CX pumps with the pistons orientated lengthwise along the pump body - the Xantia pump uses an eccentric cam to drive individual pistons at right angles.

The one way valves for each piston appear to be grooved discs, while the one way valves in the pistons on the Xantia pump are spring loaded ball and cup valves.

So there isn't really anything you could translate from a BX pump overhaul to a Xantia pump.

Although I've had a Xantia pump apart before (pics posted to this forum years ago but lost now I think) I'm not sure what would go wrong in a Xantia pump that could be fixed - I suspect either the pistons/bores wear, or the one way ball valves start leaking causing back leakage and reduced total flow rate.

Also for all versions of the pump except the Xantia V6 there is a pressure relief valve in the large cup at the end opposite the pulley, this has spring steel fingers over holes, I've heard of these fatiguing or cracking - this might cause the pressure regulator for the power steering to produce less than normal pressure, which might be responsible for poor power steering performance.

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white exec
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Re: Is there a rebuild manual for Xantia hydraulic pump?

Post by white exec » 13 May 2018, 16:55

If steering becomes heavy or notchy, this can be a sign that air is being drawn into the hydraulic fluid. Usual suspect is the pipe leading from reservoir to pump, which is under suction, and so can draw air in.

Common issue is the where the hose clips are, especially if they have been replaced by stout jubilee clips, which can deform the hose; important that a genuinely circular clip is used. If necessary, trim back and remake the hose connections.

To check for air in the fluid, after driving the car for a while, dip a sample of the LHM from the reservoir with a small, clear plastic container, and see whether there are any bubbles in it, even microscopic ones. Very low fluid level also a cause of aeration.

atr
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Re: Is there a rebuild manual for Xantia hydraulic pump?

Post by atr » 13 May 2018, 17:11

Thanx for the detailed info. it gives me at least some background about the pump's way of working. I still think it might be a good start to diagnose the pump by connecting a pressure gauge in order to determine if the pump produces the right amount of pressure or not but for that one needs to what is the value of the pressure that a normal working order pump will deliver. isn't there a manufacturer data for that?