Loss Of Power Steering At Low Speed

[Jimcoted]

Cleaned filters, changed pump, checked belt tension but problem remains. At just above tickover there is no power assistance to the steering, touch the brakes and the brake pad warning light comes on rev up and it goes off and gives me a bit of power assistance, front suspension sometimes reluctant to rise.

[Peter.N.]

If it's definitely not the belt slipping the most likely culpret is the pump itself, although its unusual unless its done a very high mileage. It could also be the pressure regulator or distribution valve assembly.

Sorry I've just read your post properly! You've changed the pump. How often does the regulator tick? should be about once in 30 seconds or more. It sounds as though you have a pretty hefty leak of fluid back to the tank. Try disconnecting the thick hose from the reservoir, (the one that doesn't go to the pump) if you have a large volume of fluid flowing from it, it's probably the regulator block, it also goes to the steering rack. How long does the brake pressure stay up after switching the engine off? If its only a few minutes, the brake valve is a likely suspect.

You could try disconnecting all the rest of the pipes in turn to see if you have a lot of fluid flowing. I dont know where they all go, but I am sure somebody can tell you.

Peter.N.

[Peter.N.]

P.S. I suppose that the screw on the front of the regulator is done up tight?

Peter.N.

[Jimcoted]

I am very close to giving up on XM's. My V70 which I stupidly got rid of never needed anywhere near the attention these things do. It bordered on boring in that you never needed to stick your head under the bonnet. With this thing there is always something that needs attention. It ran beautifully for abot ten minues before coming up with this one. I am going to change the fdv and if the problem persists then it is going off to the knackers yard new spheres and all.

[Peter.N.]

I know how you feel but they are such a nice car, ireplacable even, that I forgive them. I have been running them for over ten years so imagine the faults I have had, but I still wouldn't run anything else from choice.

Once you get them fixed they can be quite reliable. I fitted a new water pump and then a head gasket to my current one in the first 10k but I have since covered about 45k with no serious problems.

Peter.N.

[jorgy9]

Jimcoted

have you ever hydraflushed the thing? It sounds as yours could need it (slow rise). Otherwise, as u probably know, if u change the FDV with another unknown one, you just play chances that it will be better than yours. The effective move would be to remove yours, clean and refurb with Cit's kit, and put back same day.

Hydraulics are not rocket science at all, but clealry one needs to know what he's doing and why. And diagnosis of faults is not always straightforward but still not difficult if you know the system and what every bit does. My XM's hydraulics were in a bad state of neglect when I got it, much like yours (intermittant steering, rising 1min+ etc) and, in real life, it took me 3 years to sort it out step by step, but I always say that if I had a 4-post I could have tested and sorted it in a week's time. Note that 3 years ago I had no clue of hydraulic Cits. And didn't have a pressure gauge from the beginning, which is the most critical tool with such a car -unfortunatelly if u don't have one, you're like trying to guess one's heart pressure by putting your hand over his chest or seeing how high he can jump, or so-.

I have also come close to be dangerously fed up with the car, but I was lucky to have tasted the real thing for 1-2 days and was determined to repair mine and have that pleasure everyday. Nowadays, my XM rises in 12secs from bottom (non-antisink) and the steering assistance is "like electric". No need to speak of the ride...The best is that this has costed me: a few shims (to bring the regulator's pressure up to the required 145-170bar range), 2 diodes (soldered on suspension ECU), 1 new electrovalve, 5lts hydraflush, and of course, all new spheres. I'm always surprised reading how much unneeded money people spend in changing pumps, FDVs, etc (and chuck the old ones!) when actually the only thing they probably needed to do is tighten a screw or similar.

Best whishes for yours! But please try to sell it of gift it to somebody that will repair it, instead of scrapping it...

regards
George

[dean]

Hi george

Where did you get the pressure gauge from?

Dean

[jorgy9]

My indy had a full kit -which he didn't know how to use...-.

I wanted to make up my own but I'm stuck in the connectors (adaptors) part i.e. connect the gauge (off ebay) to Cit piping ; all the rest of the bits, anybody can get them. I also made a sphere pressure gauge with an old pump and a pressure regulator, but again I miss this bit to be able to operate it...at home -I now have to go to the indy each time I want to use it-.

regards
George

[jorgy9]

...and Pleiades sells all the unions etc you need to plug your gauge anywhere across the system you might need to.
G

[dean]

Thanks George

Are there any specs i can get regarding what pressures i should have, and from where?

This post has been edited by dean on September 06, 2007 06:07 pm

[jorgy9]

First, your pressure regulator should regulate the pressure to between 145 +/-5 (pump cut in) and 170 +/-5 bars (pump cut out). For the hydractive valve to remain safely open the lowest pressure is critical. But I have also read accounts as to that it is not so simple, ie it depends also on the pressure waves ie if pressure remains between the specified but drops to quickly, again the valve will have difficulties remaining open. Unfortunatelly I have never come across a really sicentific and documented explanation of all those details. The above value range is same for all Citroen's up to the Xantia generation -maybe the Gs is somewhat lower, can't rememeber-. I think the C5s work at no more than 110 bars. If you find it out of limits, the way to tune it is by means of opening it up and adding shims to the springs that regulate cut-in and cut-out. Every mm of shim adds 1 bar approximately. So adding a 7mm shim will add 7 bar. You can get those shims from another regulator from any Cit or make them up alone from any other similar shim. Citroen does not sell them anymore -my branch at least-. I think you'll find details if u run a search on hte forum.

Second, the said pressure regulator must leak within acceptable levels, specifically: it must not loose more than 10 bars in 3 minutes from engine stopped. This spec I found in the gauge-kit my indy has, and you test it by plugging the gauge at the regulator's output.

Third, the FDV has a screw that regulates the pressure given to steering. There's a nominal value for it which I don't remember, but this can always be regulated by steps simply till you get a satisfactory steering assistance. Unfortunately I don't know about any document for testing the FDV, not sure if there's anything in the club's archives, but they are all over the net, just do some searching.

If you manage to test and tune these 2 components, you've already done a huge step in ensuring everything is as it should in your system. If, having set up those 2, the regulator still needs to cut-in earlier than, say, 30secs, with a good accumulator sphere (62bars), then you know there's a significant leak somewhere. Other components can be seen leaking by eye, at the return tank or "at the source", so even if you lack the critical values it shouldn't be difficult to identify a culprit. E.g. the brake doseur valve must not leak "drops", neither the suspension cylinders, neither the height corectors. All these must just be "wet"; the electrovalve must be dry.

I hope that's enough to get u started.

regards
George

[dean]

Thanks that should give me something to think about, just got to get a pressure gauge sorted out now.

[jorgy9]

Yes, -Cit recommends a gauge of 250 bars-. LEt us know if u manage to find a solution.

regards
G

[dean]

Will do, so long as i can get a gauge for a reasonable price i should be able to rustle up some fittings to get it connected with.

many thanks Dean