Is your returning LHM (to the tank) bubbly at all?

If all else fails....perhaps you need a LHM fluid heater? - kenlowe do a preheater system (80 degrees C) (I've got one ready to fit one day when I get time!) - would work equally fine with LHM going through it instead of water.
Flash point of LHM is well over 115, so quite safe.

Desperate measures for desperate times.

I have recently read somewhere (here or XM-L or even a Xantia forum?) that someone found that the LHM returning to the tank (can't remember for sure where from, but think it was PAS or something) was completely aerated, and the air bubbles were not dispersing away from the pump intake - hence the pump was pulling in aerated LHM with nothing wrong anywhere near that part of the system.

They were rigging up some extra piping in the tank to deliver the returned LHM to the top and not the bottom of the tank.

Just an extra possible cause of air bubbles.

Cheers,
Rowan.

Yeah ive read that as well think it may have been frenchcar forum, but surely if there is no component/seal failure at a negative pressure point allowing air in, the system must have been doing this from new?. My resovoir gets a bit frothy but the ride is faultless.

Perhaps it's the LHM gremlins having digestion problems

Good point though. The pump intake is the obvious point to suck in air, but are there any others elsewhere? I don't really know how PAS works, so don't know if there are any in there.

It could be a ruptured sphere - but wouldn't that occur over a very short period and then stop pushing gas into the LHM? Besides - unless it is the anti-sink then most people who know their way around a citroen should notice a ruptured sphere fairly quickly. Perhaps if it happened and then the gas just keeps getting re-circulated round the system. That shouldn't survive citrobics though.

The power steering is only a hydraulic ram and i would have thought if there was a leak you would get lhm coming out? The suspension system should bleed itself anyway during use.
If im wrong someone should be correcting me soon!

Here is what the original poster said (it was frenchcarforum - Air bubbles in LHM thread):

Poor bloke, shouldnt someone put him out of his misery by letting him know?, or does he seem to be having too much fun !
On mine it was just the feed pipe cracked on the gooseneck near the pump, so after a call to my local cit dealer, who wanted to empty my bank and sell me into slave labour, i got a bit of hose from a local hydraulics specialist for £3, put an £8.50 piece of stainless braid over it, and run the new feed pipe around the engine along the bulkhead and into the LHM tank not only saving a small fortune, but making priming the system after work totaly pain free.
Still get froth in the tank but as i said before the ride is faultless.

I can almost see him, surounded by all sorts of components, chasing ghosts all over the system!
All he will find while hes under there is lots of other things that are knackered
But seriosly he should of joined here! The wealth of knoledge on this forum is amazing.