Hydraulic problems - non-sinker Xantia 2.0i 8v

[elvito]

HI all, I've been a silent member for almost a year and have learn a lot from the discussions in this forum. I live in Northern Thailand and the Xantia is my first Citroen and still need to learn a lot about it. The problem is no Citroen mechanic here speak English so impossible for me to discuss the problems. I only know one Xantia owner here that speaks English, but he's very busy.

For the last several months I've been dealing with hydraulic problem from LHM leak to harsh ride. LHM leak (external) has been solved. I have changed both of the height corrector, accumulator sphere, overhauled the HP pump, cleaning the filter, change right front cylinder. The car now runs on hydraurincage - 500km so far.
Overall the ride have much improved, but there are still several symptoms that need to be solved.

1. Rear dropped when starting the engine.
This happens every time I start the engine, regardless how long the car has been off. But the car can stay on normal position for couple of days. Some mentioned here that it might related to flat anti-sink sphere. I already test this - let the car move on the slope with engine off - the brake still working. So I guess the anti-sink sphere is still good.

2. When putting the car in highest position
When I put the lever on highest position, the rear went up (around 30 seconds if from lowest position), and then the front went up. but at almost its highest position, the front struggling to go up. It will up and down a little bit for about 5 seconds before finally settled.

3. Accumulator sphere ticking fast
This was the reason why I changed the accu-sphere. But it didnt solve the problem. The ticking now is between 10 seconds, in all positions, low-normal-high. In between the ticks, the HP pump work (rattle noise) for about 6 seconds. I also notice that everytime I turn the steering wheel, the pump noise louder. No air buble in the LHM tank.

4. LHM flow return line
The number Four return line on the LHM tank is flowing lot of LHM. From the diagram I found somewhere here, it is the return line from height corrector, suspension cylinders, safety valve, pressure regulator and power steering.

Ride quality
Ride quality has been improved, although from time to time I still experienced harsh ride symptom. I also feel that the steering is to light/wild, when I hit the hole/bump, the steering wheel turn a bit by it self. Also the front is bouncing a bit when I make 90 degrees turn at low speed - ie when turn right/left after stop at traffic light.


With all of the above symptoms, is it correct if I conclude that there is massive internal leak in the system?
If yes, what steps should I take to locate the source of the leak?
If not, then what cause these problems.


Thanks,
Elan

ps: where is the location of air conditioning expansion valve? is it accessible from the engine compartment?

[elvito]

I've found instructions to check internal leak in suspension cylinder. Regarding the front, do I need to take the wheels off to do this?

Any information on how to check internal leaking in height corrector, safety valve (where is this?), pressure regulator and power steering?

My friend here mentioned that to check internal leaking in brake valve also. How?

Thanks,
Elan

[Old-Guy]

remote diagnosis can be a bit difficult, but here goes.

1. What you describe is absolutely normal. You have to remember that your Xantia has an active suspension system. When you park, stop the engine, get out of the car, then later get back in, the height correctors compensate for for the changes in load and height while the engine isn't running - so the pressure in the suspension systems change. When you restart the car and the accumulator is re-charged, the suspension re-adjusts the height.

2. The usual reasons for this are:

• a. Dirty LHM filters - there are 2 (one is hidden up inside the pickup). Clean very gently with a soft brush and petrol, do not use an air-line as the nylon filter mesh becomes brittle with age.
  b. Low LHM level - with the engine running, put suspension on HIGH and wait for it to rise completely, wait another 30 seconds, check the position of the orange disc - it should be on or just below the top coloured ring on the indicator dome. Add LHM slowly to bring the disc up to the mark.
  c. Sticky front struts - with the suspension on HIGH, push the rubber boots up from the bottom and lubricate the strut shafts with LHM.

3. a. and/or b. above

4. Significant flow from the leak-off system is normal - many of the system components are designed to leak; or put it another way, it was easier to arrange the return of the inevitable leakage rather than trying to make the entire system completely leak-proof for life! Continuous circulation has the side benefit of keeping the LHM reasonably clean and lubricating the high-pressure seals keeping wear to a minimum. The power steering returns huge quantities of LHM when the wheel is turned.

Ride quality & steering - sounds like low LHM pressure (1a. b. again).

The A/C expansion valve is in the cold heat-exchanger - buried somewhere in the climate control system under the dash-board. Check that the cabin filter (above the passengers feet) has been changed recently if the A/C flow is poor with the air control on ' outside' (rather than 're-circulate').

Hope this helps