Xantia 1.9TD Loss of Power Steering, Fixed? I think

[masood_ilyas]

This fault relates to a MK2 Citroen Xantia 1.9TD automatic, dated 1998 with 145K on the clock.

This morning driving to work the Hydraulic fluid level warning came up, needed half a litre but surprisingly there was no sign of leakage on the floor. Ten miles later all of a sudden the steering became very heavy as if there was no power steering on the car. Checked the fluid level again, there was no further apparent loss. Turning the steering lock to lock made a slight improvement but very quickly back to no PAS.
Fortunately by then work place parking was at hand and thats where it is awaiting tender care and attention.

Brakes and suspension felt fine, I know there are two ports on the hydraulic pump, is it possible for one delivery port to go faulty while the other carries on fine?
There are no obvious signs of leakage around the pump or the pipes to the reservoir.
Any ideas what could be causing this loss of power steering.

As ever any thoughts will be most appreciated.

Masood

[Xaccers]

Check the tightness of the clamps on the rubber pipe that feeds the pump.
Replace them with jubilee clips.
Any air getting sucked in will affect the power steering more than the suspension as the PAS uses so much fluid.
You're not likely to be able to see any air leaks in the pipe, but open the LHM reservoir and shine a torch inside to look if it is frothy while someone turns the wheel.

[Old-Guy]

Don't wish to insult your knowledge, but:-

1. LHM and only LHM (Liquide Hydraulique Minerale) MUST be used in Xantias, any other hydraulic fluid will wreck the system. Fresh LHM is bright green to distinguish it from other fluids - it turns straw coloured as it ages (really ancient LHM can be dirty yellow-brown)

2. The level of LHM in the reservoir can only be checked with the car stationary and the suspension on HIGH. You need to wait a good 10 seconds after the front suspension has stopped moving upwards before checking the level. 1/2L is nowhere near enough to bring the level up from a level that triggers the sensor upto even the lowest mark on the indicator but it's about right from the min to max marks.

3. Leaks in the engine bay often don't show up quickly if the undertray ('floor' under the engine bay) is still in place - the undertray catches the lost fluid which then blows/flows out onto the road as the car moves.

Suggest that you don't do any checking/testing anywhere where a puddle of LHM will be unpopular. Cat litter is good for mopping oil spills - you might want to invest in a bag (about £1.50 from any supermarket) and a plastic tray (the larger the better) to put the litter in. Shove it under the car to catch the drips ASAP. You can put it in the boot when you drive home.

If you're lucky, it's only a split return pipe or a loose gland nut. As there is no pressure accumulator for the steering, that's where low pressure is first obvious around town. The suspension is locked out to save the remaining pressure in the accumulator for one last stop from high speed (if the accumulator sphere is up to scratch!). After that there's only the hand-brake - which is why it's on the front discs!

Have a look under the bonnet for leaks (all that LHM went somewhere!) and let us know what you find.

[citroenxm]

Steering "Lock Out" does not happen on later 6+2 pumps.. The pump is effectivly split into two.. One half 2 pistons, drives the suspension, the other half 6 pistons drives the PAS DIRECTLY just like a common standard PAS setup. Theres no flow divider, the pipe feeds directly from the outlet FURTHEST away from the pully passes uder the regulator and around the side over the gearbox and round and along the front edge of the subframe to the PAS rack...

S2 cars unfortunally DO NOT have this pipe coated from factory, and so suffer rust badly! I know, Im here at the moment on my mums car, so any loss of PAS will be either air ingress, BLOCKED resovior filters (!! YES Seriously! been here with mums too ) or split pipe which drains the fluid faster then it can feed the rack..

Despite the main pump being split into two, the chamber is still a single shaft drive, and it shares the LHM feed from the main tank, so the other answer in theroy is no, both side should work, unless your PAS pressure regulator (built into the pump) has packed up.. Me though, after ruling out NO leaks, check the filters for blockage.

[masood_ilyas]

After finishing work returned to find a fresh wet spot under near side wheel.
Rasied the car on highest setting, and turned the steering full out away from the kerb to discover the reason for loss of fluid. It was rubber pipe from the nearside suspension, the return pipe had split at the point it meets the metal pipe for the fluid to go back. With no spares to hand, cleaned the pipe and pushed it on again. Also used some gaffer tape to see me home at least. What I do not understand is how are the bubbles getting there? the fluid can only flow one way, on the floor and out. The return pipe will surely ends at the reservoir and takes no further part in taking the bubbles to the pump unless the return goes to the pump instead of the reservoir!. I don't have access to hydraulic circuit drawing to work this one out.

It drove all right, but it seems there are still lots of bubbles remaining in the system as the steering is hard, but driveable.
Citrobionics and turning steering from lock to lock improved it but I suspect it will take a long while for complete purgingto take place.

Time now to find two spare return pipes as the offisde pipe wont be too far behind in the perishing process.
Masood

[Xaccers]

The pump sucks LHM from the reservoir so if there are any air leaks in that rubber pipe from the reservoir to the pump bubbles will be sucked in.
If enough air is being pulled in, and it doesn't need much, the power steering won't work.

[Old-Guy]

Suspect some air got sucked into the steering circuit due to low level and now you've got some air trapped somewhere. Rapid lock to lock (park on something like nice shiny multi-storey concrete) should eventually purge it. Don't hold the steering against the stops - not good for the ram and the excessive fluid flow through the by-pass/pressure relief valve (a wet hiss) may spring a leak in the return pipe.

[citroenxm]

Just for info.. new Rams now appear Nfp on service citroen...

you could also jack the front end of the car up with two jacks.. then with both wheels off the floor you can wizz lock to lock easily...