Xm 2.0 Tct Exclusive Lpg, What's it like?

The LHM that came out of all my Citroens has been that dirty. What I haven't seen is such a build up of muck in the filter. As per usual I will be flushing several times, striping and cleaning parts in the little ultrasonic cleaner I have.

I'm aware of the non feedback nature of the electrovalve setup, providing the ECU can sense the load of the coil it will attempt to switch it. A 12v sidelight works OK for showing switching signal to the electrovalves. But as I said right at the start I think the fault lies with the hydraulic side of things, whether that proves to be low hydraulic pressue (doubtful due to the fact the front goes soft) or a split O ring (as shown below from my Xantia) or more than likely a knackered sphere.



And for those that haven't yet had that pleasure, the valve block strips down to this -



A pain to get apart without damaging something.

Steve.

This post has been edited by steelcityuk on February 12, 2009 06:00 pm

Today I stripped off the middle exhaust box to replace the Hydractive sphere, to my surprise there was a metal shield covering the Hydraulic components. I've not seen one before.



This was a faff to remove because one of the bolts was seized, it ended up snapping and the captive part fell inside the rear beam despite my best efforts with penetrating oil. When I've cleaned up and painted the shield (using Aluminium paint I think) I'll fasten it back into position using those rubber expanding cavity fixings.

This is what it looked like underneath the shield.



Needless to say I'm very pleased to see the underside and pipes so solid and rust free. A good dose around with spray grease should help keep the pivots running smoothly. After swapping the sphere the suspension has far more movement than it did so I think I can say the old sphere was well past it's best.

I've also swapped the front Hydractive sphere but that hasn't made a much difference. This doesn't surprise me because it looked OK, not ancient and rusty and it's a multilayer membrane type. Whereas the rear one is a single layer membrane type of unknown origin. Once again a good spray around all the joints and valves to help future servicing finished that off. Strangely when I loosened the pressure release bolt on the regulator a gush of LHM was dumped through the tank drain, don't know why - maybe some kind of air lock?

Ending this sudden bout of Citromania I bled about 750ml of LHM from each rear caliper whilst topping up the tank with fresh LHM. Next on the agenda is some drilled out front spheres and more Hydraflush. My theory here being that the larger orifice will allow the struts to travel further during normal driving speeding up the flushing process by allowing greater fluid flow. The fronts should have a 0.7mm opening so I'll increase it by drilling it to 1.0mm upside down, slowly with a rare earth magnet on the drill bit to catch the swarf. I'm still convinced that the turnover of fluid in the suspension cylinders is very small and what there is is provided by the leakback system so maybe this is why flushing takes so long.

Steve.

This post has been edited by steelcityuk on February 15, 2009 01:31 am

Steve,

I drilled my front sphere's out to 1mm and before the hydroflush had done its thing it gave a better ride, now that the suspension and hydraurincage has done its thing the front end is too soft with the drilled sphere's so i will be changing back soon.
Looking nice and clean underneath though, some can be a little too rusty back there.

D

How do you tell a multi membrane sphere, are they the flatter ones, are they interchangable and where do you buy from to ensure known origin?

There is a very good post somewhere on this forum about this but i cant find it,
Basically, they are identifiable by markings stamped into the sphere body, i think 3 circles indicates that it is a tri membrane type but im not 100%.
Wish i could find that old post because it had pictures too.

D

Hi Dean

Seems we need to get a few more subject entries in the self help. What I have been doing is starting a subject item there and then over time keep editing the first entry with detail as we get more information or find links on that subject. Only the subject starter (or Noz) can edit the first entry but if you do this your item can become an easily findable and searchable amalgam of all the contributors work. As long as you credit the contributor of the key points you draw in there should be no problems.

John

Hi John

I was thinking of that, since i take photo's of the work i do on the car now of posting some how to's in that section, basic sort of stuff that new members seem to ask about quite often, like the hydraulic depresurising routine and filter cleaning to MK1 dash removal, the sort of things haynes doesnt cover all too well.
Ive seen the ABS thread you have put up, again usefull info that is regularly needed and now easy to find.

D

Hi Dean

Go for it. It will be a real positive contribution to the board.

John

Well I was going to drill the old spheres that came off but the orifice is already larger than 1.0mm so I've put them back on the car tonight to see how it feels. A trip to GSF tomorrow after work for some more flush is also on the cards.

I've tried to identify the spheres with the large orifice thinking they could be IFHS comfort spheres but the markings don't match anything I can find.

The markings are -

AV BK NH75 BAR
SP CXM SF 09/03

Multilayered spheres are indentified by 3 dimples evenly spaced around the lump on the 'top' of the sphere. As far as I'm aware only Citroen use this technology. It is said to increase lifespan dramatically, which going on experience seems to be true. Maybe this is part of the technology that allows Citroen to say C5 needs no routine suspension maintenance for the first 5 years. One things for sure if I find a multilayered sphere I don't throw it in the bin.

There's loads of photos on my Flickr page if it helps anyone out.

Steve.

After work I called down at GSF and bought some more Hydraflush, so I bled out some more fluid from the back brakes before dropping it down to low and syphoning the tank then adding the hydraflush.

Already the car is so much better than when I bought it, I hope it continues to improve.

Changing the wheels is the next major step. I've seen some Volvo ones that would look right and give me the profile I want.

Steve.

This post has been edited by steelcityuk on February 17, 2009 11:48 am

I'm not convinced about drilling the centre oriface as that is the one for low amplitude fluid movement so will induce more pitch and roll, whereas the valves are for high amplitude shocks for sharper bumps.

Well I'd say if you're drilling it as an aid to flushing rather than a ride/handling modification and you're sensible then there's no problem. At the end of the day a relatively small hole still won't make a XM as 'soft' as a DS or maybe even a CX.

Personally I think the obsession with rock hard suspension and being able to corner at high speeds without body roll is stupid. Not only does it make for an uncomfortable ride on our frankly pathetic roads but it leads the foolish to push their cars past the point of their tyre grip and once that is reached no amount of anti roll technology is going to help. If you're drilling out the spheres then you should at the very least expect the handling to change and drive accordingly.

Equally I don't want a car that makes me feel seasick.

Steve.

Ive been in a Bx with slightly drilled out sphere holes, its like an ocean liner! Possibly not quite as soft as a good DS, but not very far off! Id not like to chuck it around though

That's not far off how my white XM was after fitting comfort spheres. It seemed as if it had doubled in length. Lez bought them off me, I only had them fitted for about 5 days.

Steve.

Yesterday I fitted a set of Volvo V70(?) alloys to the XM. Initial impressions are that it has dampened the jiggly feeling when going over rough or broken road surfaces. The ride itself is soft and floaty even with the other wheels so I pretty sure the suspension is working fine. Currently the alloys are fitted with 60 profile tyres but I intend to move them over to 65s. I bought a Volvo space saver wheel to keep in the boot as a spare (the LPG tank is where the spare should be).

I also changed the spark plugs and ignition leads to try and improve the smoothness of the engine when on LPG. Halfords (!) said they didn't stock leads for a XM so I bought a set for the 406, they are the right ones and fit fine. I've swapped the engine over to basic NGK copper cored plugs with the single electrode and clamped the gap down to 5mm because of the different characteristics of LPG.

Over the weekend I replaced a couple of blown dash lights, relocated the LPG changeover switch to the centre of the dash (mounted on the switch blank that would normally be used for cruise control). The stereo install was started at the same time. To get the 4AWG feed into the cabin I had to remove the LHM tank whilst routing the cable, the tank filters are still clean, so at this stage either theres still loads of gunk to come out of the system or it is clean. I'll check again in a 1000 miles or so.

Steve.