Xantia constant clicking

[Goran]

Hi,
I am back with another problem with my Xantia, i hear clicking from pressure regulator in 2 sec interval. I know from what i read here that the main suspect is the accumulator sphere. So i check it, it was ok. My question is, can the pressure regulator be faulty so it cant hold the pressure, or the hydraulic pump is on its way out and cant make enough pressure and is constantly turning on? Just to say car is rising up normally after some 5 - 10 sec depending how long its been siting, and has a good ride.

[white exec]

How did you check the accumulator sphere?

[Stickyfinger]

What is the pattern of clicking ?

How many seconds does it click for then how many seconds without clicking ?

[Goran]

@white exec: swapped the sphere from the car that is working normally
@Stickyfinger: the pattern of clicking is one click every 2 sec constantly, i think it doesn't change no matter if am driving or standing stil

[CitroJim]

It can be a faulty regulator but it's more likely a heavy internal leak...

Is the car a Hydractive? If so then the Hydractive electrovalves are prime suspects... Try forcing hard mode (by removing the Hydractive ECU fuse) and seeing if that changes the tick rate

Else that it'll be a case of determining what is leaking by checking each leakage return line and determining which item is responsible. A good suspect can be the brake dosuer valve...

[xantia_v6]

I don't think that this is likely to be an internal leask, because the pump does not deliver enough LHM to fill a good accumulator sphere in 2 seconds, even without an internal leak.

So probably a coast accumulator sphere or faulty regulator.

[CitroJim]

I've experienced very frequent ticking due to a leaky Hydractive electrovalve in the past Mike...

[Goran]

I don't have hidroactive. After I read your suggestions I suspect on the brake valve. I will post the update after I sort it out.

[Mandrake]

I've experienced very frequent ticking due to a leaky Hydractive electrovalve in the past Mike...

On my first Xantia which had a leaky front electrovalve the regulator was ticking every 8 seconds despite a good, new accumulator sphere. After the valve was replaced, the tick rate went up to about 3-4 minutes...

I don't think that this is likely to be an internal leask, because the pump does not deliver enough LHM to fill a good accumulator sphere in 2 seconds, even without an internal leak.

You're looking at it wrong - it doesn't have to "fill" the sphere from scratch, only pump it up from the cut in pressure of 145 bars to the cut out pressure of 170 bars. Even on a good accumulator sphere this would happen in under 5 seconds. Combine that with a partially flat accumulator sphere and it could easily be down to 2 seconds. (See above my cycle time with a leak with a brand new accumulator sphere)

I'd say the problem is a significant internal leak in the system somewhere combined with a somewhat flat but still usable accumulator sphere. As it's not a hydractive model I'd say brake valve or maybe an anti-sink valve.

[Goran]

I still did not get the chance to change the brake valve, but i got a new symptom. My brakes are acting weird, when am pressing the pedal there is no response from the brakes right away, and then they clamp suddenly. Its looking like beginner at first drive Also the brakes are not letting go right away after u lift of the brake. Just to say am not driving the car in this state Is this the definitive clue that brake valve is faulty and it is the cause of my initial problem, sure seams that way to me now.

[Mandrake]

Silly question - have you tried bleeding the brakes ?

[Goran]

Hmm, probably a good idea. Next thing on my check list. Kinda embarrassing oversight on my part

[Mandrake]

In general a delay in the brakes would be either lots of air in the brake lines (common on the rear brakes, not very common on the front brakes) or a flat accumulator sphere. (front brakes affected only)

But bleeding all four callipers costs nothing and doesn't take long so I'd try that first, and its a good thing to do anyway. I assume you know that bleeding the brakes on a Xantia is not done by pumping the pedal, and must be done with the engine running ?

The way I do it is take off each wheel one at a time and get the bleed hose and jar ready, wedge a piece of 2 by 4 between the drivers seat and brake pedal to hold the pedal down hard (very easy if you have electric seats to adjust the pedal depression) then whilst the engine is idling open the bleed screw to bleed then close it again - with the brake pedal held down the whole time. Then repeat for each wheel. Easy.

Because the brake system is pumped you don't pump the pedal, you simply hold it down and wait until enough fluid has been removed. If the fluid removed is clean and green just pour it back into the LHM tank, if its dirty replace the lost quantity with fresh fluid - so probably best to have a litre bottle of LHM at the ready when doing this job.