Xantia V6 leaking hydraulic pump and regulator

[Mandrake]

While out doing other work today I discovered that both my hydraulic pump and pressure regulator appear to be leaking now, the pump significantly so...

As far as I can tell, its not leaking from either of the two steel output pipes, nor the low pressure inlet pipe, it seems dry around the top of the pump where these pipes are, and no oil is visible from the top of the engine bay:

However one of the power steering piston plugs (the ones with the torx drive) that I can't see down near the bottom just in front of the alternator feels quite wet, so I'm assuming its one of the lower pistons thats leaking which means new o-rings need fitting. There's quite a lot of oil dripping off the alternator and A/C compressor even after wiping it dry then going for a drive:

I've had the hydraulic pump out of my previous 2 litre Xantia in fact stripped it down, however I was never able to get the torx drive piston caps out as they were exceptionally tight, so I'm worried that I might have trouble getting these ones out too. As well as that it doesn't look like its possible to get that piston out without removing the pump from the car, and its not obvious how difficult it is to get the pump out of the V6 as its partially hidden by the timing belt cover and I'm not familiar with the routing and tensioning of the auxiliary belt on the V6...

Can anyone who has had the HP pump out of a V6 give me some idea of whats involved ?

The pressure regulator also seems to be leaking, possibly from the sphere neck itself which seems unusual:

Is it likely to be leaking at the seal sphere, or is it more likely one of the pipes further up, bearing in mind that the pressure regulator is mounted upside down and back to front on the V6 ? I'll have to take the air filter box out next time and have a closer look at where the leak is. This leak seems to be minor compared to the one on the pump though - I wiped it clean and its still clean after a drive while the HP pump has continued to leak.

[CitroJim]

Simon,

Both common faults on the V6. Pump will be the O rings on the 2 piston side. the lower one leaks more than the top one and the lower one is inaccessible without removing the pump...

If not O rings check the rubber stub pipe on the feed pipe for small splits under the Jubilee clip.

The pump is easy to remove...

Remove the ECU box and ECUs. Remove the aux. belt and remove the pump pulley. Get at the two pump mounting bolts with a 1/4 drive socket set, long extensions, Blu Tak and a universal joint.

The regulator will be leaking from the O ring at the top. Very common on the V6..

The regulator is a bit of fun to remove but not impossible.

I believe it's all caused by underbonnet heat.

Tip for removing the Torx socketed piston caps from the pump even though they rarely leak - give them a good dead-blow with an engineers hammer before attempting to loosen them. You'll find the shock loosens them a treat.

[Mandrake]

Thanks Jim, very helpful. Could you clarify which o-ring you're referring to on the pressure regulator though - is it sealing one of the steel high pressure lines ? If so are they still available ?

[addo]

I use an impact driver to loosen/tighten the pump plugs. It negates any damage to the rather soft metal of the plugs.

Look at any exploded reg pictures to see the two O-rings; they have been the same since dinosaur days.

[CitroJim]

Thanks Jim, very helpful. Could you clarify which o-ring you're referring to on the pressure regulator though - is it sealing one of the steel high pressure lines ? If so are they still available ?

Nope, none of those. It's the big O ring on the end of the regulator body, the one that seals the plug above the big spring. It's a hell of a job to replace as you need to press the plug down and pop out a C clip...

You can prove it by removing the vaguely egg-shaped plate on top of the regulator that ties it to the gearbox, cleaning up and seeing it weep from there..

Best to let Pleiades sort it although Deanxm has posted a guide on how to do it...

If no there then give it a good clean up and suspect the functional return line rubber pipe..

[Mandrake]

Bother. I know what o-ring you're talking about, I will not be tackling THAT job myself as I know what's involved. I'll give it a clean up and see if it leaks again and from where, it seems to be a fairly minor leak compared to the pump as I cleaned both leaks up, drove about 40 miles and there was fresh oil from the pump (well, on the A/C compressor, still can't see anything on the pump) but there was no visible fresh oil on the pressure regulator. Hopefully it's just the low pressure return hose. Didn't earlier pressure regulators also have a Citroen style rubber sleeve on one of the steel pipes ? Or will my 1998 have the seal-less flared joint ?

I'm going to see if I can order some o-rings for the pump today, although its not loosing much at the moment it could get ugly real fast. Only problem is I don't have a vice to hold the pump while removing the piston caps...

PS Jim - remove the pump pulley you say ? I don't remember the pulley being removable from the shaft on my old Xantia, unless the V6 pump is different ?

[Mandrake]

Finally got around to registering myself on service.citroen.com, all it needed was a little white lie that I was a "service professional - other" and a business name of "."

I can get part numbers from Citroen Service Box as well but they might be out of date and don't include any prices... I notice that the pump pulley and the pump as a whole unit are NFP as well, why am I surprised... mind you I bet the price if it was available would be more than the car is worth.

[CitroJim]

PS Jim - remove the pump pulley you say ? I don't remember the pulley being removable from the shaft on my old Xantia, unless the V6 pump is different ?

It is, unique to the V6. It's got to be as it need the pulley off to be removable from the engine.

In fact the V6 pump is unique in other ways too. Used on no other Xantia or XM...

The pulley is held on to the hub with four 10mm screws. Very easy to remove...

[Ben82]

Finally got around to registering myself on service.citroen.com, all it needed was a little white lie that I was a "service professional - other" and a business name of "."

I don't think Citroen really care, I sent a PDF to my mum of the parts needed from the parts section showing the prices etc, she took that in, all they wanted to know was what the car was. (She couldn't remember, but showed a pic I had sent her a while back - my avatar, and they thought it was a Xsara )

[Mandrake]

I think you're right Ben.

Success, I think! I just phoned Citroen Glasgow to order a new set of o-rings for the pump, got an answer quickly, the guy on the phone was friendly and helpful, I gave him the part numbers from service.citroen.com and he had them up on his system straight away, was happy to order them for me with just a name and contact number, said they should arrive tomorrow and that I should get a text message when they arrive! Quite a revelation compared to the lack luster customer service from those who shall not be named who screwed up my wheel balance and left my wheel bolts loose.

They're within walking distance of work during my lunch break as well, so in that respect more convenient for me to pick up parts during the week - as long as I can carry them and get them on the train!

All going well I may get a new coolant expansion tank and a couple of height corrector dog bones from them next month, assuming they're still available...

[xantia_v6]

Prices are available on service.citroen, but only after you have put an item into your basket, and the user interface is a bit dodgy, so it normally takes me a couple of attempts.

[Mandrake]

Yep, found how to get the prices by adding them to the basket a full set of 9 seals is about £15.

[lexi]

I had the pump off that one Simon.........and the previous one. If you have big hands like me........they are in for a scraping

IIRC I replaced the smaller seals. The larger ones were not leaking and were very tight? I left them. I may have put a new bit of hose on at top. as I went to Pirtek to get it for one of those cars. Make sure that is tight as fluid can and does migrate from there in an insidious manner. It's hard to keep that area totally dry IME with both V6 Xantia's.

Even the MK 1 with new seals at the top of pump did not stay dry long.

[Mandrake]

Not to worry lexi, I have long skinny fingers, not big fat ones

So you replaced the 6 small green o-rings under the torx bit caps, but not the two larger black o-rings behind the hex head caps ? Its the latter that leak most often, and they're the easiest to replace fortunately. How tight they are doesn't really matter from a sealing perspective, they don't have to be super tight as the sealing comes from the bolt compressing the o-ring sideways - as long as they're nipped up and the o-ring is good they won't leak, tightening them more wont do anything.

Even since I tightened the jubilee clamps on the inlet pipe last April it hasn't leaked at all until a few weeks ago. I haven't checked the clamps again to be honest, although I can't see or feel any sign of a leak at the base of the inlet pipe. My guess is its probably the bottom one of the two hex head caps leaking, although the bottom front torx cap did feel wet as well. I've ordered the seals now anyway so its a good idea to do the job properly as I don't want a hydraulic leak that could get drastically worse without warning hanging over my head.

I'm trying to get the car back to a condition where I can trust it on a long trip - I definitely can't at the moment, for several reasons including this new found leak...

[lexi]

Better weather coming now anyway for all of these Shenanigans I seem to remember being left with the large O rings because the caps were not coming off?
Ie. they were tight..........and that was in the vice with proper leverage. You will find out soon enough which ones I speak of

It is hazy.......I have slept a few nights since and battered and welded many things into submission !
There is also my stick whittling classes........they tend to unwind me and I forget many things