Citroen c5 - air in LDS

[XantiaNonStarter]

I have a 2007 C5. About 6 months ago I noticed the suspension getting crashy/rough. I went through the LDS bleeding procedure described elsewhere in this forum:
- LDS cap off
- Suspension up to high
- Suspension down to low
- Steering lock of lock a few times
- The LDS turns light orange due to air being present. Wait until it turns back to dark orange
- Suspension to normal
- LDS cap back on
That fix works a treat but is temporary. About a week later I need to repeat

The LDS level is fine. There are no leaks. If I rock the car up and down at the front offside, I can hear a wheezing sound coming for the LDS tank area. I can't pin the noise down to an exact location.

Do you know what might be causing the problem? Is there any way of proving it is the LDS tank?

[GiveMeABreak]

Changing colour of LDS is not relevant, not sure where you got that from, but do point it out to me and I will check the post.

It is to do with the air bubbles that are present like the 'fizz' in a soft drink. After the procedure, the LDS cap is left off for a while to allow the air in the LDS to escape and the 'fizz' should be greatly reduced before replacing the cap.

If there are no signs of a leak anywhere then it may be internal the one of the valve blocks or the BHI - or the spheres themselves. When was the LDS fluid changed? If it's on the original fluid it will be near 18 years old! I'd suggest treating it to some nice fresh LDS - considering your brake fluid should be changed every 2 years......

[XantiaNonStarter]

Thanks GiveMeABreak. After the bleed process my LDS turns milky orange like the photo in this thread:
viewtopic.php?t=72576
I thought that might be evidence of very fine air bubbles but perhaps misunderstood. Is that milky orange colour normal then?

I haven't see "soft drink" fizz you describe

No I don't think the LDS has ever been changed

[GiveMeABreak]

Try not to add you own interpretation of the official procedure as the colour is not mentioned and this is how disinformation is spread.

Focus on the 'fizz' and allowing the air bubbles to dissipate. The fizz is simply the tiny air bubbles that are causing the lighter colour as they rise to the surface and dissipate. That is the 'Fizz' we are talking about - not giant bubbles as in a bar of aero.

[xantia_v6]

My experience with older LHM hydraulic systems is that air only gets into the hydraulic fluid in 3 ways:

• A component of the high pressure system (e.g. a sphere) has been removed, allowing fluid out and air in.
• A sphere has a leaking diaphragm, allowing nitrogen to leak into the hydraulic fluid.
• There is a pinhole leak between the reservoir and pump (on the suction side) allowing air to be sucked into the system. This could be a loose fitting or failing pump seal.