Sphere Life Report - 2.5

Folks,

I've recently replaced all the spheres on my 2.5 estate, and Martin at Pleiades kindly did a pressure test and report on them.

Mileage since replacement/recharge was circa 47K. Pressures in Bar.

Fronts (Cit. recharged) 18/20 (should be 55)

Front centre (Amtex new) 30 (70)

Rears 5/3 (Cit. rehcarged) (40)

Rear centre (Amtex new) 20 (50)

Anti-sink (Cit - never recharged/replaced in 114K...) 22 (50)

and...

Accum (Amtex new) 3 (!) (62)

The accum. was a real shock, as the regulator "ticking" had been at 40 seconds or so, and a pump belt failure some time back had showed that it could keep pressure for around two to three minutes.

The ride now, when soft, is truly amazing...

I can't recommend Martin and Pleiades enough! they were very helpful during the whole project, which involved repiping.

r

This post has been edited by rg on May 27, 2006 05:51 am

I,m afraid I don't do anything as ambitious as having them pressure tested, I only use the ammount of suspension movement and 'ticking' frequency to judge when they need replacing. I usually have to replace them all on buying a car but they will usually last 70-80k miles before needing replacement, maybe more often for the accumulator as it works harder.

Loss of pressure in the suspension spheres will not ffect the ride much untill there is insufficient suspension movement, as when under load the pressure will remain the same, but with loss of travel.

Peter.N.

Dare I ask what this work cost? I ask only as I'm considering pre-emptive action on mine.

Cheers, glad your chariot is back up to scratch

Hi All

It would be interesting to know the pressures when the spheres were installed. The assumption that they were correct is difficult to verify once spheres are fitted. Makes me think that a test rig such as Noz's could be worth having just to check pressures before fitting. Anyone ever done any checks?

Regards

XMexc

You can actually check all spheres' pressures -and other things- *on* the car, and you don't even need to construct all the gear Noz has built, just a pressure gauge and suitable adaptors. Of course this is valid for people that can easily lift their car in some way.
G

Hi George,

Curiosity has the better of me. Could you just explain that?

Cheers

noz

Hi Rob,

Nice to hear you got the old bus sorted. I have to agree its such a nice feeling when it hasn't been going well for a while and then you get it fixed.

I'm prepared to guess that most XM's are running around with the same sorts of pressures in their spheres. Only when the ride becomes just too hard to bear does it trigger the act of doing something about it.

Well done.

Cheers

noz

Hi Noz, the principle is eaxclty the same as doing it externalkly with a pump, only that you take advanatge of the already...available pumping setup of the car. In the thread "measuring cut-in pressure etc" I had written:

" You can also measure the static pressure of the accumulator sphere on place if u allow pressure to stabilise, switch off engine, untighten slightly 12mm to allow a slow pressure drop, it'll go slowly all the way down till a point where it will suddenly drop very fast: *that* point is the accumulator sphere pressure. Was 62 bars in mine (brand new sphere). "

It's the same for all the others, and in principle the same for measuring the pressures where the various valv-oid elements on an XM open/close. Problem is you need various different adaptors e.g. to measure the spheres on the front struts you need to undo the strut feed pipe and plug a "T" union in between, the pressure gauge going on the long tail of the "T". So, for one that can easily find such adaptors (difficult for me as I'm not in any related trade), it's dead easy to measure at any point if time. Rear is more difficult, but then u'd have to go under/lift the car to get those spheres out anyway, wouldn't you?

All the processes are described in some Citroen manuals I've been sent from other people, and also in a leaflet included with the measuring kit my indy borrowed me.

Regards
George

Hi Rob, may I ask, what's the production year of your car, ie is it an S1, S1.5 or S2?
cheers
George

Folks,

Sorry for the delayed reply.

Chadders:- Pleiades use a mixture of Amtex and their own reconditioned spheres on an exchange basis, which works out at around under £20 per sphere net. The advantage of using them is that you are sure of getting the right spec. first time. Plus, Martin is contactable for any questions. I also bought some tube from them, and can't recommned them highly enough for advice and service!

The difficulty of sphere replacement can "grow" in your mind as you hear of other folks' problems - the only antidote to this is actually trying the job! The Pleiades tool, plus time and patience results in a voyage of discovery about your XM! Plus, hopefully, a better ride! Whehever I got sight of any sphere during other work, I would give the the joint a squirt with releasing fluid, and this certainly helped, particularly with the notorious rear wheel spheres.

Jorgy 9 - Mine is a 2.5, hence S2. 1997 reg. ORGA 7175

Noz:- Thanks for the kind words and advice. Doing the whole lot yourself certainly rules out the uncertainties of having spheres recharged or dodgy ones replaced with possibly incorrect spec. ones.

There is a lessening problem of "stuck in hard in the rear" (oo-err!), which feels like some kind of valve freeing off, as there is a notable sudden softening, and a very slight drop, detectable through the seat of your pants. The period between start-up and this happening is becoming less and less,, and the actual occourance of hardness per driving session is becoming less and less. I wonder if some previously-unexercised valve is now progreesively freeing off?

When the system is in "soft" on long, fast cruises, it almost feels like the height corrector has come slightly loose, as the car truly does "float" like a small boat riding at anchor! Maybe this is the true feel of the soft XM? Conversely, I was tailgated into a roundabout by some small Jap. whizzmachine the other day, and simply left him behind by pouring on the power, causing the back end to squeal and drift out, and the chap to express surprise. We tend to forget that, for all it's tendency to go hard, a stiffened-up XM H2 system gives fine handling for a barge of its size. A real "Q" machine!

Thanks again, all! Now for the strut tops!

Photos at:- http://www.flickr.com/groups/xm_on_flickr/

This post has been edited by rg on June 08, 2006 09:43 am