Rear will not rise - SOLVED!!!!!!!! at last....

Our most popular forum is for Citroën problems, discussions and chat.
Specialising in AX, BX, ZX, Xantia,C5, Xsara, Saxo and XM. CX, 2cv & Berlingo, all are welcome.NOT for selling cars/parts!

Moderator: RichardW

tranquility786
Posts: 10
Joined: 04 Mar 2002, 19:25
Location: United Kingdom
My Cars:

Rear will not rise - SOLVED!!!!!!!! at last....

Post by tranquility786 » 04 Mar 2002, 20:17

Hi,
97 Xantia 1.9TD - non hydractive with antisink sphere
Sorry to bother you, but I have a problem with my suspension and I
would appreciate if you could shed some light on it....
The rear end will not rise and the warning lights are lit. It was OK
the day before and I have not had any problems before. I thought It
might be the rear height corrector but having had it changed today
made no difference.
Further symptoms are:
Front stays at same height -
Brakes/Power steering are OK
No ticking noise can be heard from the accumulator/pump - only when
the bleed screw is loosened slightly it ticks very fast.
Moving the lever has no efect at all on front/rear.
i am confused.....
Thank You for taking the time to read this.
Taz
Edited by - tranquility786 on 04 Mar 2002 14:19:09
Edited by - tranquility786 on 10 Mar 2002 08:55:09
0x

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Post by Dave Burns » 05 Mar 2002, 00:48

If the neither the front or rear suspension will rise, this would point to a sudden loss of hydraulic pressure in the suspension circuit, either a serious lhm leak or sudden diaphragm failure causing an internal leak, both will lead to a loss or momentary loss of hydraulic pressure in the case of the diaphragm, this pressure drop would be sensed by the security valve and will close of the supply to the front and rear height corrector's, thus preserving pressure to opperate the front brakes, the hydraulic low pressure warning lamp and stop lamp will glow as a result.
If this is what's happened, it's a case of finding the leak or bad sphere.
Don't know if the s/v is auto resetting.
Have you checked lhm level and filters.
Post back with your results and good luck.
Dave
0x

tranquility786
Posts: 10
Joined: 04 Mar 2002, 19:25
Location: United Kingdom
My Cars:

Post by tranquility786 » 05 Mar 2002, 01:34

Hi,
thanks for your prompt reply. I think you are right but the question is which component has failed...
All 4 suspension spheres are 6-8wks old - and there are no lhm leaks at all - the pump is fine as otherwise power steering/brakes etc wouldn't work and it wouldn't tick when loosening the bleed screw....
Bearing the above in mind, could anyone point me in the direction of trying to locate the failed component by process of elimination....(I would really hate to have to take it to Citroen).
I have not changed the antisink or the accumulator spheres recently. I can not hear any ticking noise at all (probably as Dave said due to the fact that there is no pressure in the system)...
Once again thank you to Dave for the previous response...
Taz
Edited by - tranquility786 on 04 Mar 2002 20:02:42
0x

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Post by Dave Burns » 05 Mar 2002, 03:10

Hi, clarify some points, what warning light's are lit, does the front suspension rise after being fully lowered (engine running).
If the s/v has tripped due to a susp/antisink sphere going down as suggested, drop suspension fully and release pressure in accumulator sphere, wait a few minutes then close release screw on regulator and restart engine with susp set to normal height, the system will fill very slowly, s/v will (hopefully) reset, the bad sphere will fill with oil and the car will rise very slowly (hopefully), don't touch brake pedal.
If no joy after this, then either the diagnosis is wrong or the s/v does not reset it's self.
Try posting here, it's a BX board but they and all Hydropnumatic Cit's have a security valve.

http://members4.boardhost.com/citroen_bx/
Dave
0x

tranquility786
Posts: 10
Joined: 04 Mar 2002, 19:25
Location: United Kingdom
My Cars:

Post by tranquility786 » 05 Mar 2002, 12:43

Hi Dave,
The stop lights (both together on the left of the display) are lit. These normally light up on startup for a few seconds and then go off when the car rises...when it was OK of course.
When setting the suspension to low/normal/high the car remains as it is - the back in low and the front in normal - it will not sink or rise no matter what but is just stuck in the same height. I can tell you that the front suspension/brakes are still fully pressurised...hope this makes things clearer...How do you locate and reset this s/v?
Taz
Edited by - tranquility786 on 05 Mar 2002 08:16:22
0x

Grant Withington
Posts: 13
Joined: 11 Apr 2001, 02:03
Location: United Kingdom
My Cars:

Post by Grant Withington » 05 Mar 2002, 20:06

This sounds like a new pump is required. The pumps have up to 6 pistons inside, which can stick etc.
0x

NiSk
Posts: 1422
Joined: 24 Jan 2002, 21:11
Location: Sweden
My Cars:

Post by NiSk » 05 Mar 2002, 20:34

A rather simple suggestion, which may well have been checked when you changed the rear height corrector, but one that could explain your situation, is that the small plastic connector from the height adjustment rod to the quadrant on the rear height corrector often breaks, giving no input to the corrector, despite full movement of the height rod/lever. A wild guess, but it's cheap to check and fix.
//NiSk
0x

tranquility786
Posts: 10
Joined: 04 Mar 2002, 19:25
Location: United Kingdom
My Cars:

Post by tranquility786 » 06 Mar 2002, 00:09

I have checked the plastic link and it is still intact. what I would like someone to tel me is: what are the symptoms of a failed height corrector? For example if my rear height corrector has seized would I still be able to raise/lower the front of the car with the lever? In my case the car does not respond at all? Why does the front not sink/rise from the normal position? Should this not rise if only the rear height corrector was affected? Therefore I am led to believe that the problem is due to low pressure which is probably why the warning lights are on... but if pressure is low why is the front not sinking at all?
Anybody?......
PS: Thanks for the hints so far....
Taz
0x

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Post by Dave Burns » 06 Mar 2002, 00:18

Positive identification of the warning lamp is essential so we don't go round barking up the wrong tree.
Have you got the owners manual, the one that comes with the car when new, this will tell you what the light means, or can you describe the graphic on the lamp.
Dave
0x

tranquility786
Posts: 10
Joined: 04 Mar 2002, 19:25
Location: United Kingdom
My Cars:

Post by tranquility786 » 06 Mar 2002, 00:26

The graphic to the left is the same as the parking indicator except it has an (i) instead of (p). The next is an oblong with (stop)
The (i) represents low fluid level or pressure. I have enough fluid so it is low pressure....
Taz
Edited by - tranquility786 on 05 Mar 2002 18:31:18
0x

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Post by Dave Burns » 06 Mar 2002, 00:53

Thought so, hyd. pressure and lhm level, there is of course plenty of fluid in the res.
Not sure what to suggest next, pumps are usually very reliable, you say the brakes work ok and the regulator ticks (cut's in) when the pressure release screw is loosened, this makes me believe adequate pressure is being generated.
The steering is on a totaly seperate circuit, I have the same car, same year, it has a 6+2 pump, that means 6 pistons for the power steering and 2 for the brakes and susp.
in efect two pumps in one sharing a common intake, but with two seperate high pressure output's, if that's not how it is on your's there will be a flow distributor to supply oil to the steering, I think it's unlikely but check it out.
Did you try depressurising the acc. sphere.
The s/v is on a bracket on the left of the front subframe and above the steering rack, it can just be seen from the engine compartment, if this has tripped for some reason, how it is reset if it is not self resetting I don't know.
Keep an open mind, it may be something else completely, but I can't imagine what.
Dave.
0x

tranquility786
Posts: 10
Joined: 04 Mar 2002, 19:25
Location: United Kingdom
My Cars:

Post by tranquility786 » 06 Mar 2002, 01:06

How do I depressurize the accumulator sphere? All I did was to loosen the bleed screw at the front...
Imagine the car in its current position: low at the back- normal at the front. The warning lights are on. This is how it is every morning....until I start the engine and as soon as the rear rises to normal the lghts distinguish and off I go...the linkI amtrying to make is netween the back rising and the warning lights going off (i) (stop).
Therefore the reason the lights are still on is because the rear is not rising...the system is waiting for the rear to rise so the lights can go off...therefore the lhm is not getting to the back at all...almost as though it is not circulating all the way round...although as I mentioned...everything at the front is OK....
I think....
Taz
0x

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Post by Dave Burns » 06 Mar 2002, 01:18

12mm Hex. headed screw on front of regulator, lossen it just one or two turns, do not remove it, things will fall out if you do.
you should hear fluid escape under pressure (hissing sound) back to the reservoir.
Dave
0x

tranquility786
Posts: 10
Joined: 04 Mar 2002, 19:25
Location: United Kingdom
My Cars:

Post by tranquility786 » 06 Mar 2002, 01:23

yes have tried that many times but there is no hissing sound at all and does not affect the height in any way except when it is loose the ticking sound comes back...
Taz
0x

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Post by Dave Burns » 06 Mar 2002, 01:50

No evidence of escaping pressure, possible regulator or pump fault then, can't see how you can have brakes (engine running) and have a pump fault, unless brakes are only working poorly, do the brakes go away the moment the engine is stopped, if so no stored pressure, acc. sphere could be buggered but that wont cause light to glow, it would just fill with oil, or could be regulator.
Too many if's and but's, it's going to be trial and error to fix yourself, the proffessionals might be able to nail it in minute's, for an arm and a leg of course.
If it were me I would slacken some unions along the high pressure lines to see where there is and isn't pressure, and how much of it, but this may be a bit dodgy and messy, try some used bits from a scrapper before forking out for new parts.
May turn out cheaper and a lot less hassle in the long run to just bite the bullet and let the proff's do it.
Good luck with it
Dave
0x