10 minute Xantia mod....what a difference!

[Mandrake]

I think its more a case that when they added the anti-sink system to keep customers (who don't like waiting for their cars to rise in the morning) happy, they didn't anticipate some of the negative side effects of the anti-sink system.

One is that the suspension is no longer self bleeding, (sinkers loose pretty much all pressure over night, so by definition are self bleeding) the other is that the spheres don't last as long when they're constantly held under oil pressure. When they're "at rest" with no oil pressure pushing on the sphere, the metal button on the diaphragm seals at the bottom of the sphere giving you "shelf life" in that state. (Eg nitrogen leakage rate drops to the shelf life rate)

They worked around that somewhat with the multilayer long life spheres though.

[Mandrake]

Any improvement Paul ?

I've done another 100 odd miles over the same route yesterday and the ride is still exactly the same, smooth and crash free, feels great at high speed, no deterioration at all.

For my car (with modification) at least, avoiding the maximum height position, or if I use it then fully lowering/depressurising the suspension before returning to normal ride height seems to do the trick Going from maximum height directly to normal ride height and leaving it there seems to leave it in a crashy state.

Now that I know what to do its a small price to pay for consistent crash free ride quality.

[isisalar]

Sadly yes Simon, I left it ticking over on low for 5 mins and went for an afternoons mixed driving. Fantastic, but the ride deteriorated over the course of the afternoon and I'm still getting bubbles in the tank. Having now experienced the ride with totally bubble free oil, notwithstanding the massive improvement from the mod and the new pipe, I'm coming to the conclusion that air's coming in from the pump, more than the mod can cope with.
When fitting the new pipe to the pump there was a drop of oil on the underside of the pump and some dried oil on top of the alternator, which I cleaned up. Checking yesterday there was another drop of oil on the pump, the alternator was dry.
There are other symptoms which may indicate low pressure from the pump also.
Car won't stay up on the brakes in the test recently discussed.
Very slow to respond to raising. Going from low upwards it takes at least a minute for the stop light to come on.
Stop warning light together with temp warning light often stays on when starting until throttle used. Not the low level light.
Still fails 'dig' test on P.A.S. after flushing and new oil.
Very poor braking compared to my other Xantias.
The pump is nicely accessible but likely to be expensive to replace. Does anyone know if repair kits are available and is it an easy job? Is it worth spreading a bit of grease over the pump?
Not the best week I've ever had and I've now got to go to the local A&E and do battle.
Cheers
Paul
P.S. There is virtually no contact between the PTFE and the oil.

[Mandrake]

Hi Paul,

I know what you mean, once you've enjoyed that crash free smooth ride its very hard to go back to it being poor again, which makes chasing intermittent harsh ride very frustrating indeed! I chased it for four years on my previous Xantia and made a lot of improvement but never nailed it like I have on this car.

If you're still seeing bubbles in the top of the tank there's definitely still air getting in somewhere. Since the modification I see no bubbles on the surface of the tank at all, its like the surface of a lake on a calm day now. There are a few bubbles within the top of the return filter but none escape outside the filter and none seem to get sucked down into the pump filter inlet based on the ride remaining good.

As for the pump, there's no repair kit as such, however all but two of the seals (9 seals) are available from Citroen for a total of about £15. The following diagram shows where leaks can occur on the HP pump:



The most common place to leak is the upper location 1 on the diagram, this is the large hex bolt that has a steel high pressure pipe going into the middle of it. There is a second one 120 degrees away which is a bolt head without a pipe going into it. These two are the caps for the two pistons that drive the suspension and brakes, they have a black o-ring down inside and its very common for them to leak.

My pump started leaking out of the blue a month or so ago, enough that the alternator was getting a good LHM bath, those two o-rings were both leaking, they were both damaged with shards peeling off the o-rings. Fitting a new set of o-rings has cured the leak. Replacing those two o-rings is easy, especially if you have the pump off the car in a large vice.

There are 6 smaller green o-rings for the power steering pistons, the caps for those are torx head drive, (lower location 1 on the diagram above) they seem to be impossible to undo without a rattle gun, but fortunately they never seem to leak either.

I've tried and failed on both this Xantia and my previous one to get those torx caps undone with a normal socket wrench and I couldn't do it without risking striping the heads or damaging the pump so they must be really tight. (Personally I'd leave those torx head ones alone unless there is evidence of them leaking, still buy the seals, but only fit if needed)

Location 2 in the diagram is a large o-ring that seals the power steering output cup, that seal is available from Citroen and fairly easy to change. Watch out if you replace this one as there is a very thin almost invisible fibre washer between the centre and end cap on the pump - if its broken then you'll need to scrape all of it off so the face seals. It seems to seal ok with just the o-ring and the faces being clean.

Seal number 4 on the diagram can occasionally leak but can't be replaced without pressing the pulley off the shaft, and isn't available from Citroen, so you'd need to get an engineering shop to do that one if its leaking unless you have a press and are good at that sort of thing.

Seal number 5 on the diagram can leak, its not available from Citroen however I have found that it can be replaced with a square section sphere neck seal perfectly well - the diameter is not quite right but the thickness is perfect and my previous Xantia ran for four years with that type of seal fitted with no leaks.

Here's a couple of pictures of the HP pump from my previous Xantia (2 litre petrol) partially stripped down:





You can see the sphere neck seal sitting in the groove on the triangular plate.

When I replaced the seals on the pump a month or so ago to fix the leak I noticed a definite improvement in ride quality and consistency, the ride was far more intermittent and changeable before that. Whether it was one of the pump seals leaking causing it or whether I just got a better air tight seal on the low pressure inlet hose at the pump end when I reconnected it I can't be sure.

Following that up with the pipe modification in the tank seems to have got it to the point where I'm not getting any air drawn into the suspension at all.

[isisalar]

Simon your a star. I'll be checking out those 1&it's brother o rings for sure. How difficult is it to do in situ? No workshop facilities unfortunately. Before going into A&E where I'm now on a 2-3hr wait to see a doctor, I had a look at those two easy nuts and they both had enough slack that I could nip them up slightly. Fingers crossed that will do the trick but nice to know rings are available and they don't cost the earth.
Last night I timed how long it took for the level stop light to go out when raising -1 minute.
Today after tightening the nuts 30 secs and it seemed to rise faster too. Was a bit of oil around the nuts so hopefully mine will repair as yours.
Cheers
Paul

[Mandrake]

Join the no workshop facilities club Paul I took my pump out at RichardW's...

I know some people have replaced the o-rings for the two suspension and brake pistons (upper item 1) in situ, I haven't tried it myself.

Its all but impossible on a V6 because of the way the pump is shoe horned in, but on other models where the HP pump is out in the open at the top of the stack of pump, alternator and A/C it should be possible, as long as you can get a socket drive onto the lower of the two piston caps that points down towards the front. Its probably pretty close to being fouled by the alternator though.

The main snag to doing it in situ is that when you remove the cap (its more like a threaded plug) there is a small spring underneath it, you don't want to loose that spring when the cap comes out, and it needs to be centrally located when you put the plug back in. Without a mirror you won't be able see what you're doing for the bottom one, and I'm not sure how easy it would be to put the spring in the bottom one and keep it there against gravity while you're trying to screw the cap in. If you do the top easy to access one first you'll at least see what it looks like.

The way the o-ring fits means if they're leaking nipping the cap up tighter doesn't usually do any good as the cap is already bedded down hard on its stop. Only a new o-ring will fix it as the o-rings seem to get pinched and deformed, possibly due to them having to bridge too large a gap.

When you're timing how long for the stop light to go out, do you mean after the car has sat overnight, or do you mean starting with the suspension fully down then raising it to normal height ?

If you're going from the suspension right down 30 seconds sounds fine, if you mean after sitting at normal height over night then that's not good, the light should go out in 5-10 seconds.

[isisalar]

Back from A&E now and while I was in there I left the car on low while it was parked. Love the way they look, right down on the floor like that. As I was getting ready to get out of the car, parked on the roadside, there was a police car alongside and the cop driving was giving me some very strange looks. I only realized later that he must have seen the car sink and it's probably something he'd never seen before, LOL. I'd just picked up a perfectly legitimate used PC and a monitor from a friend and hidden them under a dust sheet on the back seat so it's probably just as well that he wasn't that curious, could have taken hours sorting that out!
Ran the car for a few minutes and then put it on normal and timed the stop light. It didn't come on at all and the car was up in 1 minute. Those other timings were for the same operation.
The way the pump is situated on my HDI that 120 degree vee is more or less vertical so gravity is on my side for both caps so looks fairly straightforward. When removing the HP pipe is there enough slack to remove the cap or do I need to unclamp or disconnect it elsewhere do you know? Is there something really stupid I could do and disable the car? Spring excepted.
Is there any point in giving them a coat of grease in the meantime?
Now to install new computer.
Cheers
Paul

[Mandrake]

Haha that's funny, he probably was looking at the ride height and watching to see if you drove off with it in low, as that low to the ground would be illegal or at least warrant them coming over to check whether your "modified" suspension was within legal requirements...

The trick to removing the steel high pressure pipe from the pump is to unbolt all of the clamps along the front of the engine that support the pipe, depending on engine there will be two or three. This way you end up with about half a metre of free pipe, then when you disconnect it from the pump there is enough length for it to easily bend to one side without putting a permanent kink or bend in the pipe, then when you go to refit the pipe it will precisely line up at exactly the same angle as before.

If you only undo the nearest clamp (or none) you have to bend the pipe over a short distance and put a permanent bend/kink in the pipe to clear the plug, trying to bend it back to precisely line up with the hole and on the correct axis with the hole is then quite difficult and puts unnecessary strain on the pipe.

Also don't over tighten the nut on the pipe, its a seal-less flare joint and over tightening actually crushes the flare and promotes it to leak.. well nipped is all it needs. If it leaks its either because some grit has got into the joint (wipe it spotlessly clean) or the axis of the pipe is at an angle to the axis of the hole so that its not seating all the way down. (If you follow the advice of bending the pipe over a long length that shouldn't happen unless someone before you fitted it under strain due to bending over a short length)

I wouldn't put grease on the pump externally, there's nothing good that it could do, and at worst it might get onto the pulley and cause the belt to slip.

[c.morewood]

Whilst I didn't do the "mod" today. I tried the suggestion of lowering the car and undoing the depressurising screw.
What a difference!! 2 minutes of work and an amazing difference to the ride.
I'll be doing that weekly from now on.

[isisalar]

Hi Simon
My local indy Citroen parts supplier is claiming these o rings are not available any longer 'need to buy a pump mate'.
I'm off now to do battle at the nearest main agent. Any chance of some part no's or sizes? I'm only going to try the no.1's
Cheers
Paul

[Mandrake]

They're telling porkies then as I ordered some from Citroen Glasgow only a month ago

The green ones of which the pump takes 6 come in bags of 10 but the others are available individually. A complete set of all the seals that are available is only about £15.

The part numbers are on service.citroen.com if you have a login there, otherwise I'll see if I can find them for you tonight, unless someone else beats me to it. A search on the forum should turn them up too as its been discussed in several threads.

[RichardW]

03
4026 86
HYDRAULIC OIL O-RING SEAL
44,2T3
- DIESEL XU

04
4026 87
HYDRAULIC OIL O-RING SEAL
DIAM 16-TO 1,9
- DIESEL XU

05
4026 88
HYDRAULIC OIL O-RING SEAL
DIAM 19-TO 2,4
- DIESEL XU

3 is the big one under the end cover, 4 the ones under the blanks that are difficult to change, and 5 the ones under the pipes. Dunno why it says -Diesel XU only as it is lists under XU / DW diesel, and the same part nos are listed for all pumps Prices:

Part Number Description Quantity Price excl. VAT Price incl. VAT Total incl. VAT
0000402686 HYD OIL O-RING 2.55 GBP 3.06 GBP 3.06 GBP

0000402687 HYD OIL O-RING 1.35 GBP 1.62 GBP 1.62 GBP

0000402688 HYD OIL O-RING 1.15 GBP 1.38 GBP 1.38 GBP

[isisalar]

Thanks chaps
In the event I got to the main stealers and was given the same story. With a bit of browbeating and armed with Simons pictures of his recent pump overhaul they finally gave in and admitted they were available, ordered c402688 coming in on Thursday. I had to order 5 for £6.90 so I'm going to have a few spare if anyone needs some.
Thanks again
Paul

[Mandrake]

That's bizarre Paul, sounds like they're just being lazy about not wanting to process small orders.

When I ordered mine I just phoned up, gave them the part numbers over the phone and they were happy to order them up for collection even though I was ordering over the phone and had never dealt with them before.

You need to create yourself a login on service.citroen.com - not only does it have the diagrams and parts listings (that's where Richard looked it up for you) it also has the price and whether its still available or NFP (not for purchase) if its listed on service.citroen.com as available then its available despite any attempts to fob you off! If they try to tell you they can't get it just show them a print out of their own service website saying its available and for how much.

[DickieG]

A Xantia I bought from "Bernie" a few years ago had this mod done in 2007 as shown in these old threads;

http://www.frenchcarforum.co.uk/forum/v ... sc&start=0" onclick="window.open(this.href);return false;

http://www.frenchcarforum.co.uk/forum/v ... antia+ride" onclick="window.open(this.href);return false;

Having owned a substantial number of Hydractive Xantia's over the years I can honestly say that this mod didn't make one jot of difference to the the car as it rode no better or worse than the average Hydractive Xantia, from my experience the only improvement must be down to placebo, waste of time.