Suspension issues

Fox · Unread post by **Fox** » 12 Oct 2002, 03:46

Just spent some time reading previous messages and it would appear that the people on here really know their stuff

The car is a 1994 Xantia TD SX.
Thought I might as well ask if there is any solution to another problem I have, although its a pretty moot point when I cant use the car due to diesel everywhere

About, erm, 6 weeks ago I had a problem with my rear suspension. The back would refuse to come up, or fall down gradually when driving resulting in a bouncy ride. Fiddling with the height corrector every time it did it worked for a few days, but then it just refused to come up at all.
So, we decided to replace the rear spheres. We've known they needed doing since we bought the car (and negotiated the price down because of this), so we bought 3x Spheres from GSF - 2 rears, and an Anti-Sink. Took considerable effort to get off, but we learnt the knack in the end

Had a slight issue with the seals. They didnt seem to fit the spheres correctly, they were a lot looser than the old ones. But we put the spheres back on anyway, thinking thats how it should work. Screwed it all up, pressurised the system, started the car, and it subsequently dumped LHM all over the garage floor from the rear passengerside sphere

The other side was fine.
Must have been the seal, we thought. Took sphere off, cleaned up the old seal, put that on. Fitted nicely. Put sphere back on, re-pressurised. Bingo. No more LHM river on the garage floor.
Next came the Anti-Sink sphere. Problem is, the one we had and the one we were taking off looked totally different connections wise. Couldn't see how the new one would go on at all, so we left it. Asked some questions on other groups, and found out that actually the Anti-Sink sphere only controls the cars sinking overnight and isnt really required to be changed. Checked the invoice, and it turns out GSF supplied us with an XM sphere, no wonder it wouldnt fit. Put the sphere to one side with the intention of swapping it for an Accumulator Sphere to stop the new (previous owner had it fitted) pump clicking. Still not got round to that...
So, with the rear spheres done and the anti-sink left as it is, we tried to get the suspension to play ball. Nope. Not a chance - stick in high position this time. Gave up and called friendly mobile citroen specialist, who diagnosed the problem as the rear height corrector valve. He spent an hour trying to free it up and clean it off, and had no luck. Took car away, came back the next day all fixed with a brand new height corrector. Everything worked again, but I had to get the ride height adjustment sorted at an independant specialist with a big lift thing.
Total cost: £210. Hurrah

For the next few days, the rear suspension was fantastic. The ride quality was simply amazing. Then, it started to become harder and harder. Now, its back to the crap ride quality we had before the spheres were replaced (No problems with it falling or anything though, just ride quality) where I can feel every bump worse than in our Mondeo

Does anyone know what the problem could be here? It has new rear spheres. Don't suppose we messed anything up when fitting the spheres and having the issue with the seals?
Also, before all this, the car would rise from its lowest position after a few seconds. Now, the car will sit there for perhaps 20 seconds, then the STOP ( ! ) lights will illuminate, then they'll go out, and it'll happily rise back up. I've been told this is actually normal, as the system is re-pressurising. Is this the case, and if so why didnt we have it before?
Cheers!

Edited by - Fox on 11 Oct 2002 22:47:44

Unread post by **alan s** » 12 Oct 2002, 04:30

OK, let's start step by step.
This one :- "Also, before all this, the car would rise from its lowest position after a few seconds. Now, the car will sit there for perhaps 20 seconds, then the STOP ( ! ) lights will illuminate, then they'll go out, and it'll happily rise back up. I've been told this is actually normal, as the system is re-pressurising. Is this the case, and if so why didnt we have it before."
I'd suggest firstly checking the LHM level as well as the condition of the LHM and the cleanliness of the filters. Also did you bleed the air at the 12mm bleed screw at the regulator?
When this is checked, then go through the Citroen aerobics & see how it goes. This possibly may not have any effect on the ride, but needs to be got right before you proceed any further.
Go to Common PProblems & fixes on this forum to check out what you'll need to know on LHM condition & the Citroen aerobics.
Alan S

Fox · Unread post by **Fox** » 12 Oct 2002, 04:51

Thanks for your reply.
The system was emptied of LHM, and then completely refilled by the mechnic who fixed my height corrector. The level seems right.
Am I correct in assuming this is not normal? I posted somewhere else (Xantia-L list I think) and a few people there said it was becuase when you lower the car it displaces the fluid or something, which then needs to be pumped back in..
As you can tell I'm no expert

Unread post by **alan s** » 12 Oct 2002, 05:44

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>
Thanks for your reply.
The system was emptied of LHM, and then completely refilled by the mechnic who fixed my height corrector. The level seems right.
Am I correct in assuming this is not normal? I posted somewhere else (Xantia-L list I think) and a few people there said it was becuase when you lower the car it displaces the fluid or something, which then needs to be pumped back in..
As you can tell I'm no expert

<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>
I suppose it can be argued to a point that theoretically this is the case but in practical application, it is usually a case that when that warning light/buzzer comes on, it's due to lack of pressure that triggers the warning. I've found in most cases that this is due to the level either being a bit too low in the tank or the filters being clogged with minute particles of dirt, both of which causes problems with the pumps ability to suck in fluid as fast as it's trying to discharge it.
As a rule, I disregard the yellow disc in the tank as a guide to fluid level & instead work on being able to just touch the fluid with my index finger tip when the car is set at normal ride height with the engine running. If it's slightly overfilled, don't worry; if it's grossly overfilled, still don't worry, they have an overflow, but if it's underfilled, the slightest leak can create what appears to be big problems if you are not fully au fait' with the operation of the system. I personally think this underfill problem is used as a milking cow by a lot of disreputable repairers to put their greasy little hands into your wallet.
Alan S
Edited by - alans on 12 Oct 2002 00:47:26

Fox · Unread post by **Fox** » 12 Oct 2002, 15:14

Right, I've checked the level, and if anything, its slightly overfilled.

Unread post by **alan s** » 12 Oct 2002, 16:44

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>
Right, I've checked the level, and if anything, its slightly overfilled.

<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>
O.K. That's got that one out of the way, now check the condition of the LHM and the cleanliness of the filters which are inside the tank.
Here's the details on checking the LHM
http://www.aussiefrogs.com/snippets/lhm_story.htm
Then next do the aerobics (susension from lowest to highest a few times) followed by the purging at the pressure regulator; that's the 12mm bleed bolt I spoke about before; only loosen it about half to one turn when the suspension's at the highest adjustment position. It should make a hissing sound & a 'thump' as it stops. At that point you screw it back in, then lower & raise again and loosen again; do this 4 or 5 times.
This should start to show an improvement in the pressure if any air is trapped in the return of the system.
Alan S

Dave Burns · Unread post by **Dave Burns** » 12 Oct 2002, 21:35

A Xantia with all good sphere's and rising from the lowest setting with engine at idle, will indeed illuminate the low pressure warning light and stop light for a short period, this as you have already been informed is normal, though car's such as estate's with higher pressure rear sphere's may not perform this trick.
The reason for it is simple enough to understand, whan the car is lowered to the minimum setting, all the hydraulic pressure in the suspension is released and the oil returns to the reservoir, the suspension having had all its supporting fluid taken away, the car naturaly drops to the lowest position.
Also the gas in the sphere's will expand (since there is no longer a compressing force being applied to it) and discharge the oil stored in them back to the reservoir, thus the suspension system is totaly discharged of any pressure.
When you then open the valves in the height correctors by positioning the height lever to the normal setting, fluid is once again admitted into the suspension circuit, the accumulator sphere quickly discharges into this circuit because of the already empty (lower gas pressure) rear sphere's, and also the fact that the hydraulic pump can't supply this volume of oil in such a short space of time, its during this phase that the warning lights will glow.
When the sphere's are kaput, there is no gas left in them to push out the oil when the suspension is lowered, hence they remain full or nearly full, with no easily compressable element's in the suspension, such a car rising from the low setting will not be able to discharge its accumulator sphere to the level required to operate the warning light's, this is the reason you have not experienced it before.
A car with a knackered accumulator sphere may also display the same symptom's.
Dave