I had a call from a friend yesterday and she was with her late s2 24v XM at the mechanic's. The mechanic is Citroen friendly but not a full on hydraulic specialist. They were both puzzled at what the car was doing and as I was heading their way today I said I would drop in and have a look.

When I arrived at the workshop the car was "arse up" parked at the two post hoist. I assumed that the anti sink was keeping the rear up. However the car would not lift its nose. There is also no brake pressure.

The mechanic lifted the car with the hoist and we could see noting bizarre underneath (by the way, it is always a pleasure to look under a Cit of any type in Aus - none of that nasty rust stuff you guys go on about - particularly on cars from BXs on)

There were signs of very minor leakage from the 6+2 pump, but this is acceptable and the car has done 260 000km.

We opened and closed the bleed valve on the regulator and interestingly there was no "clunk" which to me either means the pump is not producing pressure OR the regulator is jammed open.

Power steering functioned normally indicating the 6 piston side of the pump is OK. There was obvious flow of returned fluid into the LHM tank.

A phone call to Peter Raffels at Pleiades in Queensland seems to confirm that the regulator is the culprit.

Has anyone here experienced anything like this with their XM or perhaps Xantia? What was the cause and solution?

Anyone have a comment?

Hi UFO

First thing is that I though that all V6 XM's were not Anti-sink fitted right up to the last ones made in year 2000. A look at the hydraulic pump will tell you with the single pipe pump of the original system or the twin pipe of the 6by2 anti-sink pump. If it is conventional hydraulics then something is stopping the back dropping rather than a problem with the front. DerekW might well be able to confirm as he has a very late built V6.

John

Hi Craig,

I understand that the 6+2 pump and its associated antisink was fitted from 1998 on to the V6. Logic says that the problem is either a stuck front height controller, failed 2-piston part of the pump or the regulator.

The lack of brake pressure points to your theory of either pump or regulator being faulty. Problem as you well know is proving one or the other. How about cracking the output from the pump to see whether there's a regular pulsed flow?

I don't know if the regulator is capable of being stripped and repaired, I would have thought so but maybe George could confirm.

Derek

Sorry, I should have added that "late S2 24v XM" to us means Exclusive with anti sink fitted. This is a late 1998 car I believe. Yes it has 6+2, back to front and sphere pointing down regulator etc. I left the mechanic with instructions on how to test flow. Have heard no more so maybe he is on the trail.