Xantia Hydractive disaster!

[xantia_v6]

What are the minimum components you need to assemble a working valve? I have a damaged one here, but I need to check which bits are salvageable.

[aerodynamica]

Thanks, well I'm promised a refund for the eBay item.

[aerodynamica]

Well I've to send it back. It's a bit annoying though because that firmness regulator is the modified type. I wonder if I could keep it and maybe have a partial refund...

[white exec]

You could try to haggle. Maybe see whether he has an additional one too, and do a deal...?
You can find some EVs if needs be...
You have the required damper inserts (and unions) in your existing valves.

[aerodynamica]

Hi Chris, I asked him and they only had one. I think i could just send it back. Just a shame as they'll no doubt launch in in the skip.

Curiously the item is the modified late type but it already had the correct pipe union fittings as i tried the pipe in it to check. Maybe someone had already fitted it to an earlier car.

Anyway I have now received the electrovalve from chevronics - nice quick delivery.

[aerodynamica]

As an aside observation the Xantia remains 'up' for ages.

Normally the front sinks in lad than 10 min and the rear less than an hour.

With the stretched spring now in the rear and the front with the 'plugged' electro valve, it stays up for hours. 5 hours ago i got to work and the rear suspension is still at normal height. The front is sunk now but it has taken all this time.

Pretty much confirms what was already known about leaking electro valves.

[aerodynamica]

The EV from chevronics has separated lovely and the small spring measures a tad over 9mm.

Soon to refit- I hope that 'plugged' one comes out ok....

[aerodynamica]

Drove the 20 miles back to home on a variety of roads and it was working well. Nicely smooth and good switching.

Regulator cycle time up to a nominal 24 sec which is ok.

I've not quite decided what's to happen to the faulty firmness regulator from the eBay guy. I decided to clean it up a bit and remove the dampers etc. The amount of sand blast media in the block is actually not much - most of it is in the 2 fittings for the 10mm pipes. Removing the large fittings shows the dampers have actually prevented tge media going in to the unit. I've cleaned the lot with compressed air. If i can remove the terrible condition EV from this I might just keep it.

[white exec]

That sounds like a good result, Graeme, after all the hassle.
If that's all that's wrong with the ebay regulator, might be worth keeping it. You could even fit just that one, maybe to the back of the car, if that's the most crashy/thuddy. You might then be "a first" to have a half-converted Xantia! No reason not to do one end at a time.
Really pleased you've sorted the EV.

[aerodynamica]

Thanks Chris, it's amazing how well it rode when only the rear EV was working. I had to fit the coil part of the front EV to the plug because the system didn't like it being out of circuit.

[aerodynamica]

Yes it was Looking good when the clear tube on the front EV was showing no leakage.

Can confirm that the pump-regulator cycle thinness have remained high now. We're 20 sec and up to 40 now. Seems it has to bed-in to an extent.

Anyway, all done now and riding a lot better. It should have been quite a straightforward job but the snapping of the rear EV unit was not something I was prepared for- not to put anyone off the job.

Incidentally the 'corkscrewing' effect of the original thread I'd hijacked was something I think I was also getting with my car. I feel this has improved with the EVs being 'serviced' . Although I'm still getting a mild wayward feeling at times where the front feels like it wanders a bit when the weight transfers after going over a bit of a hill on the road (say 10-20m long)

I just got new tyres fitted that are back to the former 45 profile. This i think, has helped but there's still something amiss.

Got new front ball joints and rear arm bearings in the last 18m, tracking checked and adjusted.

I wonder about the Xantia rear sub frame mountings. Edith the 'passive rear wheel steering ' system, what is the long term durability of the flex mountings? I've been so far unable to test them and they 'look' ok..

[aerodynamica]

After a few days, and only really one trip out to fit a new back box, it's all still good but I'm disappointed to find that the click times are returning to higher frequency.

It's not as fast as it had been pre- electrovalve work but it's still faster than I'd have thought at about 12 seconds.

I was watching a little video I took of my previous mk1 sinker that had the same pump-FDV- regulator set up albeit non hydractive and it was running for a full 45 seconds between cycles.

I might give up on trying to solve it because it is largely working fine.

[white exec]

One more tactic could be to pull off the return pipes at the reservoir, one by one, and see which might be returning fluid at quantity. Bit of detective work then follows (as return pipes tend to join up), but it might give some clue. I know you've had quite enough visits to the reservoir in recent times...

[aerodynamica]

Chris that last sentence could be taken another way! Like I'm fed up and might want to jump in the reservoir

I'll give it some time as I noticed it also send tho vary to an extent. Some times it is faster and other times it settles to the improved count.

It's still riding better

[aerodynamica]

Update on the Hydractive investigations.

After some investigation I decided to keep the ebay firmness regulator and fit it to the front of the car using the new electro valve. It has been thoroughly cleaned of any sand with several shots on an ultrasonic cleaner and compressed air.

It has been covered elsewhere, but the revised version of the firmness regulator has one hydraulic pipe fewer. The challenge was to trace the routing of the pipe and find the port to plug with a bleed nipple. It turns out the pipe follows the same route as the thick 10mm suspension pipe and also the pipe from the height corrector. They all route together around the LH side of the engine bay. The spare pipe and the height corrector pipe route underneath the LHM tank where they both connect to 2 different pipe unions that were right next to each other making it easy to work on them (after first moving the LHM tank). So, removed the pipe end and plugged with a spare brake caliper bleed. I've left the spare pipe in place for now in case I have to reverse it all at some stage.

So, old regulator out

Old and new

All the bits swapped

And fitted

Fitted and tested for leaks etc.

As you can see I've got a theme of painting the hydraulic parts that have been overhauled - bright green brake caliper paint..

It is happily working and the bleed nipple that the modified regulators have, showed its worth because the amount of air that bled from it was surprising.

Observation!
the regulator from ebay was a Xantia one for sure because the dampers (removeable) have the same center hole size and the same etch marking '2.6'. But! I noticed that the disks of the dampers are different. The dampers from the late type modified regulator have fewer disks as seen. They have a smaller diameter top disk on both inside and outside ends of the damper.. I wonder why? Here's the difference between the two damper variations - you can actually see the thicker stack of damper disks from the original damper (left) and the thinner stack of the late type (right). All other aspects of the damper are identical.

I decided to fit the later type of dampers to the regulator to fit to the car.

So all in, after a fait bit of citaerobics and a play, the front suspension -seemed- softer and a bit more satisfying but that is stationary. Out on the journey home the ride is easily better! The harshness has all but gone. It's decidedly floatier and the sport mode is as taught as before.

Being the modified type of firmness regulator, they suspension switches to soft mode when the door is opened even when the system pressure is at nil as tested by releasing the main accumulator pressure and then checking the soft mode still engages - it does! The back suspension of course, didn't follow suit because it still has the original type regulator at the back.

Pressure regulator cycle time!
So the PRV cycle time had been really bad - 13 seconds and the front suspension sinks really quick after parking.

I timed the PRV cycles before swapping the unit.

After the new front firmness regulator was changed it was hugely improved:

Massive! well over a minute and a half! so much so that I only recorded 4 regulator cut-in/out in over 5 minutes!

Back home this evening and I note that after 20 miles of the improved ride the cycle time has once more returned to faster cycles.... Still not as bad as before but strange that it has crept back to fast tick times.

Anyway, glad it is done and will keep a watch on the performance of the system with this new part fitted.