Suspension fluid reservoir

[citroen since 1973]

So, I've topped up the LDS reservoir with 3.5l of fluid, it's now midway between the two slotted areas on the filler tube. Tightly screwed the cap back on, started the engine and waited. Added some revs and then moved the suspension setting from low to normal and after 5 mins, nothing's happened. Stopped car, removed the cap, expecting to see the level dropped, but it was exactly the same. Checked under the car for leaks and nothing. Repeated the process, adding more revs and changing the setting to the highest level, still nothing - including no leaks, which is a relief!

When I first removed the cap on the reservoir I noticed that there was an escape of pressure from the system, I haven't noticed any re-pressurisation yet. Also, the rear suspension was still at the normal run height, until I lowered it completely to check the fluid level, this hasn't come back up. Could there be air trapped in the system?

Sorry guys, but I now need some more help please. BTW, I was a house builder, designer and developer for 40+ years, so I am a very practical person, but not so with cars/engines. I can strip most things down and follow instructions to rebuild/repair, but only if I have a diagram to follow and it's basic, like replacing brake pads, electric window operators etc, so please bear with me. Thanks, Paul

[GiveMeABreak]

Hi Paul

1) Always check the suspension fluid level with the car on the LOWEST suspension setting and then ensure it is between the 'a' & 'b' marks as shown.

2) Bleeding:

• Apply a pressure of 0.5 bar in the LDS fluid reservoir (if necessary, especially if the car has been depressurised).
• Start the engine.
• Wait for the vehicle height to stabilise.
• Place the suspension height control in the "HIGH" position.
• Place the suspension height control in the "LOW" position.
• Turn the steering from lock to lock slowly in each direction a few times (do not hold the steering wheel at each lock)
• Stop the engine.
• Check the LDS fluid level.

So, you may find the system has got some air in so perform the bleeding procedure and then take if for a spin to get the oil circulating, then leave the cardboard underneath overnight to see if has started leaking again.

[Hell Razor5543]

I know that Paul (citroenxm) has said he was able to re-pressurise the system by sealing his lips around the reservoir top (without the cap) and blowing hard into it (the suspension needs to be on a setting other then its lowest for this to work). While I believe him, I personally wouldn't do this (as LDS probably isn't good for you! ), so what I have done is to get an LDS cap from a scrap car, drill a hole through it (of suitable size), and then fit a car tyre valve in the hole. With that in place of the normal cap (at the time of requirement), a couple of stokes from a bike tyre pump would put enough pressure for the pump to prime and get working.

[GiveMeABreak]

When I first removed the cap on the reservoir I noticed that there was an escape of pressure from the system, I haven't noticed any re-pressurisation yet. Also, the rear suspension was still at the normal run height, until I lowered it completely to check the fluid level, this hasn't come back up. Could there be air trapped in the system?

Don't worry about pressurising the system - it is only needed if the system has been totally depressurised using the diagnostic equipment - and in cases where the system has been drained. For normal use you don't need to pressurise it when the car is on the lowest setting, and as you already have topped it up and raised and lowered it, you don't need to concern yourself with this part.

There will be a slight hiss when undoing the cap - this is normal, but the fluid is not under high pressure whilst in the reservoir.

[citroen since 1973]

Hi Marc and James, thanks very much for your advice.

I'm a bit confused Marc. It does seem like the system did loose most of the LDS fluid, although there does appear to have been about 1.5l left in it. I have filled it to the lower "A" mark you've shown, whilst on the lowest suspension setting, should I make this level slightly higher (it's the Mk3 with the Sport setting)? I haven't managed to raise, or lower the system, it hasn't budged when I've altered the height setting. I've also not had any hiss from the system, it's not pressurising. I haven't tried moving the steering wheel, but will do. Is it okay to drive it carefully in the lowest setting to try and get the fluid circulating?

Repressurising the system by using a bike pump does make sense, but is there any other way of doing this without needing a spare LDS cap, as I'm not hopeful of finding one locally?

[Hell Razor5543]

Well, you could always give Pauls' method a go!

[GiveMeABreak]

Hi Marc and James, thanks very much for your advice.

I'm a bit confused Marc. It does seem like the system did loose most of the LDS fluid, although there does appear to have been about 1.5l left in it. I have filled it to the lower "A" mark you've shown, whilst on the lowest suspension setting, should I make this level slightly higher (it's the Mk3 with the Sport setting)? I haven't managed to raise, or lower the system, it hasn't budged when I've altered the height setting. I've also not had any hiss from the system, it's not pressurising. I haven't tried moving the steering wheel, but will do. Is it okay to drive it carefully in the lowest setting to try and get the fluid circulating?

Repressurising the system by using a bike pump does make sense, but is there any other way of doing this without needing a spare LDS cap, as I'm not hopeful of finding one locally?

1) No - do not drive it in the lowest setting - that will make no difference at all and will damage the system.
2) Sport mode makes no difference to the fluid levels - always fill to the same levels - between 'a' and 'b' with suspension on the lowest setting regardless.
3) Increasing revs makes no difference. I think you are thinking about the old hydropneumatic systems that were run from engine pumps - these Hydractive 3+ systems don't; they use an electric pump.

So when you start the car, can you hear the pump engaging? If you can, leave the car idling with the suspension on the normal position for about 5 minutes. Then report back. If the car has been low on fluid it may take a while.

[citroen since 1973]

Thanks, will give it a go now.

[citroen since 1973]

Okay, a result! When I started the car again and moved the steering a little, it quickly started to rise up. After a bit of playing around with the height settings, everything seemed to be getting back to normal. I took it for a couple of small runs and then a futher faster one and I'm delighted to say that all appears well. I did put a little more fluid in, as the level did drop slightly, but I can't find any leaks - nothing is dripping at the moment! I've put large areas of cardboard below the engine/steering, from wheel to wheel and done the same between the rear wheels. Maybe tomorrow I'll have a bit more of an idea what's going on.

Your item 3 above reminded me of something from years ago Marc. The first Citroen I had was a wonderful GS 1220 Club Estate, in 1973. I remember visiting friends in Yorkshire one weekend and whilst driving with the car loaded and 4 adults onboard I came to a roundabout on an "A" road. As I pressed the brake switch (not really a pedal) nothing happened, but the road was quiet and I fortunately managed to get around it and coast to a halt using the handbrake, which slid out of the dasboard. When I looked under the bonnet a rubber hyraulic pipe, on top of the engine had fractured where a jubilee clip fastened it to a junction. Fortunately, we'd just past a service station and and even more good fortune led to them having a bottle of ELF LHM fluid on the shelf. I had tools in the car and simply cut off the fractured pipe, refitted the clip, topped up with fluid and we were on our way. Scary at the time and we were lucky, but since then, I've always carried tools with me and for all of the cars, except this C5, carried a bottle of, now redundant, LHM fluid. I've now installed the remaining one and a half bottles of LDS fluid in my sons car and told him to get some tools!

Thanks guys for your help and for the wonderful information you put on this site. Even though I suspect many people looking at this site for help and guidance may not have the technical skills to do much of the work themselves, the ability to understand most of what you say and then take this knowledge, often in printed form, to the local garage and become involved in helping them solve our problems, is hugely helpful.

Thanks,

Paul.

[citroen since 1973]

BTW James, I'm really pleased that I didn't have to perform a blow job on the LDS reservoir!!!!

[Hell Razor5543]

BTW James, I'm really pleased that I didn't have to perform a blow job on the LDS reservoir!!!!

[citroen since 1973]

Update - since Friday the car did local journeys around Telford. We checked for leaks and the LDS and all was fine. My son drove the car back to Birmingham on Sunday night and it was fine. He's checking levels again before he returns to Telford tomorrow. I'm at a loss to understand where 3.5l of LDS fluid disappeared to, but I'm keeping my fingers crossed!