Leaky ram and electrovalve!

Unread post by **Dommo** » 02 Jan 2010, 18:26

Just had a read of the owners manual and it says for my car fuse 3 under the steering wheel, so I just tried to remove that one and it also isn't the right fuse... Doh!

Unread post by **CitroJim** » 02 Jan 2010, 18:32

Dom,

I'll look up in my diagrams later and identify other contenders...

I pulled the rear hydractive sphere block off the scrap V6 today and the electrovalve has a terrible case of corrosion. A wonder it was not leaking...

Unread post by **Dommo** » 02 Jan 2010, 18:59

Such a stupid design fault isn't it...

Is it not possible to shot blast them and refurbish or has it gone too far?

Unread post by **CitroJim** » 02 Jan 2010, 19:25

Dommo wrote: Is it not possible to shot blast them and refurbish or has it gone too far?

No, refurbishment is impossible as once corrosion bites, that's it. Game over.

The electrovalves already cost a fortune and are not easily available. I reckon the time will come when we'll have to get a batch of alloy bodies made up. Luckily they're relatively straightforward to disassemble (off times they do anyway when you try to remove them) and it would be easy enough to transfer the good internals to a new body.

The body must be alloy otherwise the solenoid slug inside would not move!

So, the re is a good reason why they're made of alloy and originally they were anodised to give them some protection...

This is what their internals look like:

And here is a bare body of one (bright goldy silver thing by the sphere) still in a hydractive sphere block. It came apart attempting to remove it...

Unread post by **myglaren** » 02 Jan 2010, 20:10

Would brass not work and be more corrosion resistant or would the copper component promote eddy currents in something of that mass?

Unread post by **CitroJim** » 02 Jan 2010, 20:20

Umm, now there's a thought Steve.

I have a feeling, going back to my old Strowger telephone exchange days, that brass had the effect of "slugging" a PO 3000 relay and making it either slow to operate or slow to release...

Certain relays in the exchange selectors were deliberately "slugged" in this way.

I'll have to dig through my notes. I still have my old theory books...

Unread post by **Dommo** » 02 Jan 2010, 21:17

Looks lovely and clean inside. Shame the externals don't fare quite so well.

I'm going to have to ask how to replace the rear electrovalve too at some point, once mine arrives that is.

Is the bit at the top of your picture the slug you mentioned?

Cheers

Unread post by **CitroJim** » 02 Jan 2010, 21:40

Hi Dom,

No, the slug is the cylinder at the bottom right of the picture with the larger of the two springs sticking out of the top of it..

The brownish thing at the top is the coil.

For a good discourse on electrovalves and hydractive in general, have a look at this thread...

Unread post by **Dommo** » 03 Jan 2010, 13:57

That makes sense, cheers.

I had a look at the front ram yesterday to see where/why it's leaking, and the whole thing is wet, and the gaitor is chopped up, with a couple of cable ties on it for some reason, all they do is rub on the ram shaft though! It's really rather bizarre, I'll have to get a photo of it before I change it.

Unread post by **Dommo** » 03 Jan 2010, 17:08

More problems/causes for concern...

There's a rapid ticking sound (2 or so ticks every second) down and in front of the battery. Is this likely to be the electrovalve as it's in that sort of area. If so what needs doing to sort it? I'm fairly sure it's not the regulator but I could be wrong.

Also when steering while stationary after starting up (not tested while I'm moving as it's SORN'd and got no MOT) there's a strange noise, sounds like an air leak but I can't be sure... I'm not sure if this only happens while building up pressure or not.

Unread post by **CitroJim** » 03 Jan 2010, 18:01

Hi Dom,

The two second ticks you are hearing come from the pressure regulator, the block behind the main accumulator sphere attached to the gearbox. The pressure regulator maintains system pressure at 170 bar and allows reserve storage of hydrauic pressure in the accumulator sphere much like a battery stores electricity. The tick you hear is the pressure regulator cutting in an out to maintain that pressure, much like a thermostat maintains a temperature.

The ticks should occur at least 30s apart and in some, with good hydraulics and accumulator, the ticks can be minutes apart. A fast tick rate such as yours suggest the accumulator sphere is totally flat and cannot hold any reserve of pressure and the pump is working flat-out to try and maintain some pressure. This is bad for the pump and the pressure regulator and eventually one or the other will fail under the strain. Get that accumulator replaced as soon as possible!

Another cause may be leaky electrovalves in soft mode only. Again, pull the hydractive fuse (Engine Bay F8 - 20A - yellow) and see if the tick rate changes in hard mode. F8 is tyhe fuse. It did not change in the series 2.

The Activa has a second accumulator under the battery tray that may also be flat.

For a good grounding in all matter hydraulic, have a look at
The Citroen Technical Guide. It does discuss the Activa and is an excellent text. It's a big PDF but very easy to read and digest.

Wish you were nearby, I'd say drop round for a bit of instruction and learning!

Unread post by **Dommo** » 03 Jan 2010, 18:52

I wondered if it was that but I'm sure it didn't click like crazy when I went to buy it. It should click like crazy when building pressure I assume?

There's a bit of fluid on the front of the HP pump if that means anything.

Best bet I suppose would be to leave it idling for 5 minutes, then it should be up to pressure and see how often it clicks?

It is very slow to rise, the stop light takes about 30s to go out and then it'll take a good 2 minutes to rise up. If I keep pressing the brake pedal loads of times to use up some pressure the stop light doesn't come on, but then I dont know if it would do?

The guy I bought it off reckoned the accumulator sphere was too high pressured but I don't remember why he thought that...

I've definately removed fuse 8 in the engine bay and they electrovalves still buzz when I open a door with the engine off. And I checked my owners manual which said hydractive suspension was driven off fuse f3 under the steering column, when removed the valves still buzz with the doors open!

Thanks Jim, and yes it would be handy if I knew someone local to me with the know how on these things!

Unread post by **CitroJim** » 03 Jan 2010, 19:04

No, the regulator will not tick at all until system pressure is reached so in the initial 30 or 40 seconds an Activa takes to build pressure it won't tick.

Activas do take a long time to build full pressure and it is normal for them to take 30-40s before the stop light goes out. Also, they are very slow to rise. All perfectly normal.

No, the stop light should never come on when pressing the brake pedal. The only time you may see it on is if you go to full high, then down to full low and then back up again. It may come on briefly as it rises from full low. It's not unusual. By the way, going from high to low and back again repeatedly is a good exercise for the hydraulics and it's a routine known as "Citarobics". It is good to do it regularly as it purges any entrained air from the system.

A bit of fluid on the HP pump is not unusual and is fixed by replacing an O ring under the pump delivery valve. Costs pennies. Do teh accuumulator first as a flat accumulator will make the pump prone to leaks. The reason is that a flat accumulator causes spiky pressure pulses in the system and these can cause leaks. I sometimes wonder if a duff accumulator and the resulting spikes kill rams too...

There is no such thing as a too high pressured accumulator. It's charged to 62 bars, the highest in the system just about and it can only loose pressure, never gain it! Odds on it has NO pressure in it. Maybe that's what he meant...

Unread post by **Dommo** » 03 Jan 2010, 19:23

I just went to check how i'd describe the noise it makes, it's very odd..

Basically I've figured out that the noise I heard isn't the regulator.

At first all you hear is the injectors ticking their heads off. Then once the suspensions raised up (at least 2-3 minutes for the front to raise) you hear about 5-8 or so ticks in the space of about a second, then nothing for well over a minute, seems like 90 odd seconds, then 5-8 ticks in a second, then nothing again. It's possible that it ticks before the suspension's raised but i'd have to go and check again, and its too cold for that!

But here's the odd thing, the noise I was hearing sounds almost like a loose spark plug down below the n/s headlight that starts after a few minutes of running... I'm so confused.

by the way, if I've disconnected the hydractive fuse I'm assuming the electrovalves shouldn't buzz?

Edit - by loose spark plug I mean the sound is like a pht pht pht noise.

Unread post by **CitroJim** » 04 Jan 2010, 07:31

Dom,

That noise may be due to a blowing exhaust manifold gasket.

If it reduces slightly as the engine warms then it's a good possibility and quite a common problem on the CT engine.

Replacing the gaskets, because of the turbo being in the way, is fun...