2.5td Brief Hydraulic History

Hi,

It didn't look too bad but until it's taken apart who knows.

Steve.

Well today I've drained off enough LHM through the brake circuits to add another container of Hydroflush then the snow started.

I'll report back on any progress. Currently doing loads of press ups with the car in hard mode.

Steve.

An interesting thought crossed my mind the other day. The white XM which had lovely suspension was being driven about by it's previous owner in sport mode (all the time from what I gather) when the strut top failed and folllowing this he sold it. Could it be the continuous use of sport mode that helped keep the hydractive blocks working correctly or is it coincidence? I know that in S2 cars it doesn't lock into hard mode but just alters the switching points and duration. It seems unlikely I know.

Steve.

Have also thought the same, could be, who knows...
G

Well today there has been a development. I awoke this morning to see 3 inches of snow on the car and the back suspension on the bump stops. I assumed rightly or wrongly that the weight of the snow had disturbed the car and it dropped. The car sat like that until about 3pm when we went out for Sunday Lunch. I started the engine and the rear rose but as we drove up the road I noticed the back suspension felt solid! Very very bouncy like flat spheres. After about 1/3 of a mile the suspension reverted to its normal (firm) self. We drove about ten miles out of town for lunch and were probably in the pub for 1 1/2 hours. When we came out the rear was down again, not right down but on the way. When we got under way the back felt normal stiff again not bouncy. The car has now been on the drive for three hours and no sign of dropping!

I know there is still lots of gunge in the system and can only assume some valve or other was held open by a foreign body allowing the fluid to drain back

I can't wait for the weather to pick up so I can carry on and finish the rear spheres. I might take the rear centre off again and try bleeding while the engine is running, and do the two wheel spheres the same.

Sounds like u had an interesting Sunday!

btw do u have antisink? State of the sphere?

These symptoms with "hard at start up" then "soft a mile afterwards" or "soft if u do up then down" etc, I read lots in the Planete-Citroen forum, it is anti-sink related (if not height corrector), but don't ask me how...

cheers
George

Hi George, I think the anti sink is original. When I changed the rear centre sphere the a/s didn't look like it had been disturbed ever. If I remember all the spheres I changed have been original so far! So much for Citroen trained mechanics maintaining the car!

Just did 80,000 miles last week!

This post has been edited by demag on April 06, 2008 07:51 pm

So it makes sense if u also put it in the programme earlier rathen than later, to also take advantage of hydraflush flowing properly at those points (I guess).

Seems things are already moving though!

cheers
George

See "Hydraflush" thread, have moved it there rather than here.

This post has been edited by jorgy9 on April 09, 2008 12:32 am

Well I haven't done much to the Xm for some time now but I've noticed a marked deterioration in the front suspension. It is now worryingly firm again (not bouncy) and I give bad roads a lot of respect. I am hoping to get the Bx on the road soon (just needs tax) and then I can take a look at the Xm. I think I'll see if I can lube the hc's in the short term.

I still haven't replaced the rear spheres and until the Bx is done I don't really want to mess. Swmbo will NOT be happy with two dead cars! I have noticed another oddity recently, o/s front higher than n/s front Very strange. The back looks ok, just the front. Probably about 20mm in it looking at the wheelarch above the tyre.

One good point though, the rear has definitely softened up while on the move. But standing with the engine running still feels firm and looks slightly high. Interestingly though I had the steering tracked the other week and as the fitter drove into the garage it settled to the correct ride height at the rear as soon as he started the engine

Hi Dave!

Good to update your thread, I should do the same to mine soon -just allowing the news to accumulate-...!

Just for the record, I don't remember if u had actually put hydraflush or some other product (petrol? or was this "Wirdy"?), or just continuing with LHM? I bought myself a little suction pump for quick LHM/hydraflush drainage.

Re. the height difference from side to side, I've read that in various forums, it is rare but does happen, problem is I can't remember anyone having found an explanation! Unless the car has had an accident and its suspension elements are not symmetrical anymore, the height of each side is only "regulated" by the car's weight (and the antiroll bar), which just brings the two sides at equal heights, that's why Cit didn't need to use one height corrector per side but can use one per axle, no? The only other element I can think of that is interfering in this formula is the friction from the suspension cylinders. So what if one of your front cylinders is *so* sticky at some point in its course, that it beats the the antiroll bar's force and just doesn't want to go *that* little bit higher (the 2cm you mention). I cannot think of anything else. Plus, this fits with you mentioning the front getting stiffer recently.

If I were you, seeing your car is an S2, I'd buy one of the new cylinders for sale on ebay at the moment from AEP for £80, and try it on the side that now remains lower, I'd bet! it would go right and soft.

cheers
G

Hi George,

Yes changed to hydraflush about 1800 miles ago. One good point the rear is softer on every trip now although I still haven't changed the rear wheel spheres. Once I change them I'm sure the rear will be a LOT softer. I just need to sort the front. How did you say you checked the pressure? Is there a take off point where I can connect a hydraulic pressure gauge?

Ah, so could be the hydraflush moving dirt around. It seems same happened to Dean -his suspesnion became harder a while after putting hydraflush-. So leave it there to do its thing and see. Remember, mine started becoming softer only after 2,500mls. I had not noted any deterioration though.

Measuring: You mean the pressure produced by the regulator? You have to put the gauge at the outlet towards the suspension -the thicker of the 2 outlet pipes (the other one is for the steering)-. One detail escapes me: what to do with the steering outlet. I think it should be blanked -I think in theory this outlet should not leak if the steering is at straight line, but what if the FDV is out of tune?-. So just in case I'd blank this outlet -after all you want to know what the regulator is doing *alone*-. So the regulator has to regulate between 145 and 170bar, +/-5 bar.

Second test, testing the regulator's internal leaking. With gauge connected same way, switch off engine just after a cutting off (ie at the highest pressure). Then wait 3 minutes and record the pressures before/after. The regulator must not have lost more than 10bars in those 3mins.

cheers
George

I just changed the front spheres for the old fronts off the BX! Bit of a desperate move but the o/s strut top doesn't look good and I needed a quick fix. The front is softer (ish) now. Probably a bit wallowy because of the bigger damper holes but not extreme.

I'm really starting to wonder if those GSF spheres were any good that I fitted. If I get time the BX will be taxed tomorrow and I can do a bit to the Xm and hopefully get the pressures checked/corrected and maybe fit a new strut top, or at least give the old one a good check.

More soon.

Well after a couple of days the car is definitely riding softer. Stange thing is if I do Citrobics the rear stiffens up so for now they are out.

BX is taxed, I'm off work tomorrow so hopefully I'll give it a run round and if all is well I can get some jobs done on the Xm.