Best way to fix my Activa ?

[CitroJim]

You will always see a considerable return flow from the pressure regulator when the system is up to pressure but this should stop when the system is building pressure.

Did you check for excessive leakage from the hydractive and roll stiffness electrovalves?

[naxmon]

Hi Jim,

sorry for replying so late... well after checking and following all your suggestions, I ended up changing the pressure regulator which returned a lot of LHM when building up pressure (should not, right?).
Additionally, re-checked and stretched springs on all 3 electrovalves. With these two actions, the system improved considerably. However, I decided after that, to dismount the SC/CAR corrector: changed it for an used one and the system improved further. I am positive now that I have now a very steady (not perfect) system with reasonable, but acceptable leaks and good pressure behaviour (more than 20secs between pump charges on the pressure regulator, even when hot).
I thank you Jim and all for the suggestions, now I am focusing on improving the assisted steering, it is very heavy, even after purging air, cleaning filters, the steering is very heavy and has not improved a bit.
I think I might have some issues on the steering valve. I changed the pump on my car for another good V6 hydraulic pump and again, no difference at all. So I suspect the problem is not pump related.
One curious behaviour on my V6 and another V6 here in Colombia, when accelerating the car (stationary) over 4000RPM the steering gets unusable, very hard... No idea why.
I'll keep you posted on the result of these actions and again thanks all for your help. Any ideas on the V6 heavy steering are very welcome!

Regards,

Nicolas

[CitroJim]

Good news on the suspension side of things

As for the steering, the V6 has a separate pressure regulator mounted low down on the LH (your driver's side) chassis rail near the pressure regulator. This is unique to the V6 and the pump, unlike every other Xantia, does not have the pressure regulator built into it.

The first check is to ensure you really are using a genuine V6 pump as using any other will effectively give you two pressure regulators in series and potentially give you the very heavy steering you have...

Another major cause, if you are sure the pump is right, is a seized and very tight universal joint at the bottom of the steering column just above where it connects to the rack... It may need a good spray of lubricating fluid to free it off..