I've Got That Sinking Feeling!, XM rear suspension

[gbarter]

Hi there!

I bought my XM last year and was told the suspension was completely replaced 2 years ago. Since then It has only done around 10'000 miles and everything pretty much does what it should.

Although...

When I place the auto box into reverse the back end sinks to the floor.
Plus she sinks at the rear when coming to a full stop and then slowly climbs back up after around 30 seconds or so when stationary.
Occasionly the sensor detects there is a problem with hydralic pressure but not that often.

We're looking to pull a caravan this year and would like to get this sorted!
So before blowing a budget at GSW (German Sweedish French) I'm going to resolve this myself.
My experience is not that great on the suspension and have been pretty lucky over the years, but now my time has come?

Any ideas you have would bill greatfully recieved.

Thanks, Graham.

[jorgy9]

Hi Graham

the rear sinking *that* much when coming to a stop sounds like the brake doseur valve is leaking alot. If the sinking cycle is repeated as you are stationary, then it could also be the rear cylinder(s) leaking -but I understand it only happens once-. You can check how much these leak by removing the appropriate return pipe found on each cylinder, engine running. If they are dripping drops, then this would defitnitely contribute to the sinking -it's excessive-.

30secs for the rear to climb back up is too much, surely you either have a very clogged height corrector, or, a big leak, or both. On my car the rear corrector reacts in no more than 10secs to height changes.

If they replaced the rear cylinders with brand new then these should be OK, but can you confirm that?

If you could also put the year and model of your XM in your signature [go to "my controls"], it would make it easier for others to help.

cheers
George

This post has been edited by jorgy9 on March 15, 2008 09:25 pm

[citroenxm]

Sounds more like a Brake valve and the slow reaction I would guess could be more like a Tired Pump, or faulty pressure regulator, that could also cause the quick sink ALONG with the brake valve..

The brake valve is out the way under the front scuttle trim along the bottom of the windscreen.. so the engie is not in the way if it needs chaging.

I understand these valve are all the same on XM and Xants?? Yes / No.. Im sure someone will correct me..


Rgds


c

[gbarter]

I believe everything was geniunly changed a couple of years ago although the guy I bought it from did not keep his reciepts. Doh.
He was the second owner and had it for a couple of years and drove it until the whole suspension crashed down!

The brake thing makes most sense and I'll give that a closer look, cheers for the thoughts it's much appretiated.

Graham.

[DerekW]

Just a quick add on to what jorgy9 and citroenxm have written. If you're suffering from an internal component leak the return fluid must go back to the hyd tank. It might be worthwhile checking each of the return pipes that go into the top, from that you should be able to narrow down the faulty component.

Derek

[gbarter]

Cheers, thanks for that!
Apart from this odd quirk she's a great specimen.