Leaky ram and electrovalve!

Unread post by **Dommo** » 31 Mar 2010, 12:44

Cheers Jim. It's just a bit odd that the sinking end has swapped around, it definately used to stay up at the front and sink at the rear, now it's the opposite!

How do you test the anti sink sphere? I saw your test of the accumulator where you sit in the boot until it raises (if it can) and then get off, and try again, and will do that test later on when I get chance.

Thanks.

Unread post by **CitroJim** » 31 Mar 2010, 13:37

Yep, seen that. If the rear is in the habit of sinking for whatever reason the front stays up. My project Activa did exactly that before I sorted the hydraulic problems at the rear. Now she sinks just like yours!

Anti-sink spheres are hard to test Dom, to be honest.

One thing for sure is they have no bearing on sinking except that they have a marginal role in helping the rear not to sink when the car is first started and pressure is building by helping prevent a premature opening of the anti-sink valve.

Given the proper role of the anti-sink as a rear brake accumulator, you could somehow check that the rear brakes work for several presses of the pedal just after the engine is switched off.

Practically doing this is hard as the rear suspension really needs loading up before the brakes work that effectively. I can't think of a method that would give reliable results right now except trying to bleed the rear brakes with the engine off. On an Activa the wheels allow access to the bleed nipples so you could try this with the rear under load. If you can bleed the rears when the engine has been off for a few minutes, you can say the anti-sink is reasonable. This is theory; I've never tried it.

A sphere tester will test it in an instant of course but for the low cost of one, if it looks elderly, replace it...

Tzani · Unread post by **Tzani** » 14 Apr 2010, 10:18

Hello guyes,
I'm new in your forum, but I have spent a lot of time fighting with my Activa.

I'm verry happy to find such rich of information regarding the Activas forum.

I have read the entire thread and I want to share my experience with the sinking rear end.

My Activa does this whenever she wants.
Sometimes it can keep the clearance for a week, other times it starts sinking as soon as the car is switched off.
I have checked all spheres and they are OK.
There are no leakages that I'm able to see (externally).
So I start to wonder regarding the anti-sink valve.
But if I left the car in highest position, it stays like that - no sinking, which should mean that the anti-sink valve is OK, but...

Unread post by **CitroJim** » 14 Apr 2010, 10:57

A very warm welcome Tzani

It is good to know there is an Activa in Sofia...

You must tell us all about your Activa

I will discuss later the many reasons why the rear of an Activa can sink. The anti-sink valve is good otherwise, as you say, it would not stay up in high...

Is it sinking right down or just sinking a little?

Tzani · Unread post by **Tzani** » 14 Apr 2010, 11:57

Thank you very much for the warm welcome!

It is sinking right down (when it decides to sink).

Unread post by **Dommo** » 08 May 2010, 00:21

I realise this is a bit late, but the other day I noticed that the front end sank while I was sat in the car, the engine had been off for probably 30 minutes, and the battery was disconnected - we had been faffing, and found a hissing noise around the throttle body which turned out to be (we think) the idle control valve. When we disconnected it - as long as we kept the throttle open slightly to ensure some air got into the engine - the hiss went and the car would run, just about. This put the check engine light on for a few seconds after turning the car on, hence the battery being disconnected.

What is it that keeps the front of the car up, does the anti sink valve operate all four corners? It really is as though something works well, then after anything from 15 minutes to a couple of hours, it just gives up (even without electricity, so it is solely a physical change after a certain period of time) and releases pressure, but only at the front! Despite it potentially being normal, it is very odd...

DickieG · Unread post by **DickieG** » 08 May 2010, 07:50

Dommo wrote:What is it that keeps the front of the car up, does the anti sink valve operate all four corners?

There is an anti-sink valve for each end of the car, Hydractive/Activa's will sink if you open the doors after the engine has been switched off as that opens the Hydractive valves. So for instance if I leave one of my car's parked for several days it will remain at the same height provided I don't open any doors. If a door is opened a week later the car will sink further, leave a door open for 30 minutes and the car will pretty much end up on its bump stops.

Unread post by **Dommo** » 08 May 2010, 10:46

That was my thinking Dickie, hence why I found it odd that it did it even with the battery disconnected. So what I could do ideally is undo the battery, turn the engine off, then disconnect the battery straight away, to see if it still does it?